Patent Publication Number: US-11662538-B2

Title: Slidable fiber optic connection module with cable slack management

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is a continuation of U.S. patent application Ser. No. 16/894,533, filed Jun. 5, 2020, now U.S. Pat. No. 11,131,818; which is a continuation of U.S. patent application Ser. No. 15/966,738, filed Apr. 30, 2018, now U.S. Pat. No. 10,684,435; which is a continuation of U.S. patent application Ser. No. 15/206,834, filed Jul. 11, 2016, now U.S. Pat. No. 9,958,629; which is a continuation of U.S. patent application Ser. No. 14/187,470, filed Feb. 24, 2014, now U.S. Pat. No. 9,389,384; which claims the benefit of U.S. Provisional Patent Application Ser. No. 61/770,165, filed Feb. 27, 2013, which applications are hereby incorporated by reference in their entireties. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to fiber optic telecommunications equipment. More specifically, the present disclosure relates to a fiber optic module designed for high density applications. 
     BACKGROUND 
     In telecommunications industry, the demand for added capacity is growing rapidly. This demand is being met in part by the increasing use and density of fiber optic transmission equipment. Even though fiber optic equipment permits higher levels of transmission in the same or smaller footprint than traditional copper transmission equipment, the demand requires even higher levels of fiber density. This has led to the development of high-density fiber handling equipment. 
     An example of this type of equipment is found in U.S. Pat. No. 6,591,051 (the &#39;051 patent) assigned to ADC Telecommunications, Inc. This patent concerns a high-density fiber distribution frame and high-density fiber termination blocks (FTBs) which are mounted to the frame. Because of the large number of optical fibers passing into and out of the FTBs, the frame and blocks have a variety of structures to organize and manage the fibers. Some structures are used to aid the fibers entering the back of the frame and FTBs. Other structures are provided for managing the cables leaving the FTBs on the front. The FTBs also include structures for facilitating access to the densely packed terminations. One such structure is a slidable adapter module that is incorporated into the FTBs to allow selective access to the densely packed terminations inside the FTBs. 
     Further development in such fiber termination systems is desired. 
     SUMMARY 
     The present disclosure relates to a fiber optic telecommunications device. The telecommunications device includes a slidable fiber optic connection module with features for cable slack management. 
     According to one example embodiment, the fiber optic telecommunications device includes a frame and a fiber optic module including a rack mount portion, a center portion, and a main housing portion. The rack mount portion is stationarily coupled to the frame, the center portion is slidably coupled to the rack mount portion along a sliding direction, and the main housing portion is slidably coupled to the center portion along the sliding direction. The main housing portion of the fiber optic module includes fiber optic connection locations for connecting cables to be routed through the frame. The center portion of the fiber optic module includes a radius limiter for guiding cables between the main housing portion and the frame, the center portion also including a latch for unlatching the center portion for slidable movement. Slidable movement of the center portion with respect to the rack mount portion moves the main housing portion with respect to the frame along the sliding direction. 
     According to another aspect of the disclosure, a fiber optic telecommunications device includes a telecommunications rack defining a right side, a left side, a front side, a rear side, a top, and a bottom, the telecommunications rack defining mounting locations arranged in a stacked arrangement from the bottom to the top of the rack, the mounting locations configured to receive telecommunications modules defining fiber optic connection locations. The telecommunications rack further includes a cable storage bay located at one of the right and left sides of the rack adjacent to the mounting locations, the cable storage bay defining a front cable storage area and a rear cable storage area, the front cable storage area including cable management structures configured for managing and guiding cables toward and away from fiber optic connection locations that are accessible from the front side of the rack and the rear cable storage area including cable management structures configured for managing and guiding cables toward and away from fiber optic connection locations that are accessible from the rear side of the rack. The telecommunications rack further includes a trough defined at the top of the rack, the trough configured for extending cables to other telecommunications racks in a front to rear direction, the trough further defining a cable drop-off communicating with the cable storage bay for extending cables to either the front cable storage area or the rear cable storage area of the cable storage bay for further connection to the fiber optic connection locations. 
     According to another aspect of the disclosure, a fiber optic telecommunications rack system includes a first telecommunications rack and a second telecommunications rack. The first telecommunications rack defines a right side, a left side, a front side, a rear side, a top, and a bottom, the first telecommunications rack defining mounting locations arranged in a stacked arrangement from the bottom to the top of the first telecommunications rack, the mounting locations configured to receive telecommunications modules defining fiber optic connection locations, the first telecommunications rack further including a first trough defined at the top of the first telecommunications rack, the first trough configured for extending cables in a front to rear direction to other racks, the trough further defining a cable drop-off for guiding cables to the fiber optic connection locations of the telecommunications modules mounted at the mounting locations. The second telecommunications rack defines a right side, a left side, a front side, a rear side, a top, and a bottom, the second telecommunications rack defining mounting locations arranged in a stacked arrangement from the bottom to the top of the second telecommunications rack, the mounting locations configured to receive telecommunications modules defining fiber optic connection locations, the second telecommunications rack further including a second trough defined at the top of the second telecommunications rack, the second trough configured for extending cables in a front to rear direction to other racks, the trough further defining a cable drop-off for guiding cables to the fiber optic connection locations of the telecommunications modules mounted at the mounting locations. A cross-aisle trough is coupled to and communicates with the first and second troughs of the first and second telecommunications racks for extending cables between the first and second telecommunications racks. 
     A variety of additional inventive aspects will be set forth in the description that follows. The inventive aspects can relate to individual features and combinations of features. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad inventive concepts upon which the embodiments disclosed herein are based. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a front, left, top perspective view of a high-density fiber distribution frame shown with a plurality of slidable fiber optic connection modules having features that are examples of inventive aspects in accordance with the principles of the present disclosure mounted in a stacked arrangement thereon; 
         FIG.  2    illustrates the high-density fiber distribution frame of  FIG.  1    with one of the slidable fiber optic connection modules in an extended position; 
         FIG.  3    is a rear, right, top perspective view of the high-density fiber distribution frame of  FIG.  1   ; 
         FIG.  4    is a front view of the high-density fiber distribution frame of  FIG.  1   ; 
         FIG.  5    is a right side view of the high-density fiber distribution frame of  FIG.  1   ; 
         FIG.  6    is a left side view of the high-density fiber distribution frame of  FIG.  1   ; 
         FIG.  7    is a top plan view of the high-density fiber distribution frame of  FIG.  1   ; 
         FIG.  8    is a front, left, top perspective view of one of the plurality of slidable fiber optic connection modules of  FIG.  1    shown in isolation; 
         FIG.  9    is a front view of the fiber optic connection module of  FIG.  8   ; 
         FIG.  10    is an exploded view of the center member of the slide assembly of the fiber optic connection module of  FIG.  8   , the center member shown slidably mounted to the rack mount member of the slide assembly; 
         FIG.  11    illustrates the center member of  FIG.  10    with the latch rod inserted into the base member thereof, the center member shown slidably mounted to the rack mount member of the slide assembly; 
         FIG.  12    is a perspective view of the latch rod of the center member of the slide assembly of  FIG.  10   ; 
         FIG.  13    is a left plan view of the latch rod of  FIG.  12   ; 
         FIG.  14    is a top plan view of the latch rod of  FIG.  12   ; 
         FIG.  15    is a front view of the latch rod of  FIG.  12   ; 
         FIG.  16    is a perspective view of the floating plate of the latch rod as shown in  FIG.  10   ; 
         FIG.  17    is a front view of the floating plate of  FIG.  16   ; 
         FIG.  18    is a top plan view of the floating plate of  FIG.  16   ; 
         FIG.  19    is a left plan view of the floating plate of  FIG.  16   ; 
         FIG.  20    is a cross-sectional view of the fiber optic connection module of  FIG.  8   , the cross-sectional view illustrating the rack/pinion arrangement among the rack mount member, the center member, and the main frame member of the module; 
         FIG.  21    is a perspective cross-sectional view illustrating the rack/pinion arrangement between the rack mount member and the center member of the slide assembly; 
         FIG.  22    is a close-up perspective cross-sectional view illustrating the interaction between the floating plate of the latch rod and the rack mount member of the slide assembly; 
         FIG.  23    is a cross-sectional view of an example adapter having a media reading interface configured to collect information stored in memory disposed on a fiber optic connector; 
         FIG.  24    illustrates a telecommunications rack with a plurality of prior art distribution frames or blocks mounted thereon; 
         FIG.  25    illustrates a rack mount telecommunications panel having features that are examples of inventive aspects in accordance with the present disclosure, the telecommunications panel including another embodiment of a slidable fiber optic connection module having features that are examples of inventive aspects in accordance with the present disclosure; 
         FIG.  26    is a front, right, top perspective view of one of the plurality of slidable fiber optic connection modules that are positioned adjacent the left side of the panel of  FIG.  25   , the connection module shown in isolation; 
         FIG.  27    is a front view of the fiber optic connection module of  FIG.  26   ; 
         FIG.  28    illustrates a top view of a fiber optic connection module of  FIG.  26    mounted within the panel of  FIG.  25   ; 
         FIG.  29    is an exploded view of the center member of the slide assembly of the fiber optic connection module of  FIG.  26   , the center member shown adjacent to a rack mount member of the slide assembly; 
         FIG.  30    is a cross-sectional view of the fiber optic connection module of  FIG.  26   , the cross-sectional view illustrating the fiber optic connection module at a neutral retracted position with respect to the telecommunications panel; 
         FIG.  30 A  is a close-up view of  FIG.  30    illustrating the front and rear floating plates of the centering member of the slide assembly resting within the elongate middle notch of the rack mount member of the slide assembly when the connection module is at a neutral position; 
         FIG.  31    is a cross-sectional view of the fiber optic connection module of  FIG.  26   , the cross-sectional view illustrating the fiber optic connection module at a forwardly extended position with respect to the telecommunications panel; 
         FIG.  31 A  is a close-up view of  FIG.  31    illustrating the front floating plate of the centering member nested within the front notch of the rack mount member and the rear floating plate of the centering member abutting against the front edge of the elongate middle notch of the rack mount member when the connection module is at the forwardly extended position; 
         FIG.  32    is a cross-sectional view of the fiber optic connection module of  FIG.  26   , the cross-sectional view illustrating the fiber optic connection module at a rearwardly extended position with respect to the telecommunications panel; 
         FIG.  32 A  is a close-up view of  FIG.  32    illustrating the rear floating plate of the centering member nested within the rear notch of the rack mount member and the front floating plate of the centering member abutting against the rear edge of the elongate middle notch of the rack mount member when the connection module is at the rearwardly extended position; 
         FIG.  33    illustrates the position of the pivot door of the telecommunications panel when the connection module is at a neutral retracted position; 
         FIG.  34    illustrates the radius limiter of the connection module contacting the pivot door to unlock the door as the connection module is being pulled in the forward direction; 
         FIG.  35    illustrates the pivot door being opened by being contacted by the right wall of the connection module; 
         FIG.  36    illustrates the position of the pivot door when the connection module is at the full forwardly extended position; 
         FIG.  37    is a front, right, top perspective view of the main frame member of another embodiment of a slidable fiber optic connection module having features that are examples of inventive aspects in accordance with the present disclosure, the fiber optic connection module suitable for mounting to the telecommunications panel of  FIG.  25   ; 
         FIG.  38    is a front, right, top perspective view of the main frame member of  FIG.  37    with a fiber optic cassette mounted thereto; 
         FIG.  39    is a rear, left, top perspective view of the main frame member and the fiber optic cassette of  FIG.  38   ; 
         FIG.  40    illustrates the main frame member and the fiber optic cassette of  FIG.  38    in an exploded configuration; 
         FIG.  41    is a close-up view of one of the equipment mounts of the main frame member of  FIG.  37   ; 
         FIG.  42    is a close-up view of one of the removable cable retention members of the fiber optic cassette of  FIG.  40   ; 
         FIG.  43    is a close-up view illustrating one of the bottom tabs of the fiber optic cassette of  FIGS.  38 - 40    snap-fitting into one of the openings of the main frame member of  FIG.  37   ; 
         FIG.  44    is a front, right, top perspective view of the fiber optic cassette of  FIGS.  38 - 40    shown in isolation; 
         FIG.  45    is a front, right, bottom perspective view of the fiber optic cassette of  FIG.  44   ; 
         FIG.  46    is a top view of the fiber optic cassette of  FIG.  44   ; 
         FIG.  47    is a bottom view of the fiber optic cassette of  FIG.  44   ; 
         FIG.  48    is a front view of the fiber optic cassette of  FIG.  44   ; 
         FIG.  49    is a right side view of the fiber optic cassette of  FIG.  44   ; 
         FIG.  50    is a front, right, top perspective view of another embodiment of a fiber optic cassette suitable for mounting on the main frame member of  FIG.  37   ; 
         FIG.  51    is a front, right, bottom perspective view of the fiber optic cassette of  FIG.  50   ; 
         FIG.  52    is a top view of the fiber optic cassette of  FIG.  50   ; 
         FIG.  53    is a bottom view of the fiber optic cassette of  FIG.  50   ; 
         FIG.  54    is a front view of the fiber optic cassette of  FIG.  50   ; 
         FIG.  55    is a right side view of the fiber optic cassette of  FIG.  50   ; 
         FIG.  56    illustrates a front, right, top perspective view of the fiber optic cassette of  FIG.  50    with the cover removed to show the internal features thereof; 
         FIG.  57    is a top view of the fiber optic cassette of  FIG.  56   ; 
         FIG.  58    is a front, right, top exploded perspective view of the fiber optic cassette of  FIG.  50   ; 
         FIG.  59    is a rear, left, top exploded perspective view of the fiber optic cassette of  FIG.  50   ; 
         FIG.  60    illustrates a front, right, top perspective view of the body of the fiber optic cassette of  FIG.  50   , with the cover and one of the adapter blocks removed therefrom; 
         FIG.  61    is a rear, left, top perspective view of the cassette body of  FIG.  60   ; 
         FIG.  62    is a top view of the cassette body of  FIG.  60   ; 
         FIG.  63    is a left side view of the cassette body of  FIG.  60   ; 
         FIG.  64    is a close-up perspective view illustrating a right ramped tab of the adapter block snap-fit into an opening on the center divider wall of the fiber optic cassette body; 
         FIG.  65    is a close-up perspective view illustrating a left ramped tab of the adapter block snap-fit into an opening on a side wall of the fiber optic cassette body; 
         FIG.  66    is a close-up top view illustrating the right ramped tab of the adapter block snap-fit into an opening on the center divider wall of the fiber optic cassette body; 
         FIG.  67    is a close-up top view illustrating the left ramped tab of the adapter block snap-fit into an opening on a side wall of the fiber optic cassette body; 
         FIG.  68    is a cross-sectional view of taken along line  68 - 68  of  FIG.  56   ; 
         FIG.  69    is a close-up cross-sectional view illustrating the left ramped tab of the left adapter block snap-fit into an opening on a side wall of the fiber optic cassette body; 
         FIG.  70    is a close-up cross-sectional view illustrating the right ramped tab of the right adapter block and the left ramped tab of the left adapter block snap-fit into the opening on the center divider wall of the fiber optic cassette body; 
         FIG.  71    is a close-up cross-sectional view illustrating the right ramped tab of the right adapter block snap-fit into an opening on a side wall of the fiber optic cassette body; 
         FIG.  72    is a front, right, top perspective view of one of the adapter blocks suitable for mounting directly on the main frame member of  FIG.  37    or mounting to the fiber optic cassettes of  FIGS.  44 - 49    and  FIGS.  50 - 55   ; 
         FIG.  73    is a top view of the adapter block of  FIG.  72   ; and 
         FIG.  74    is a front, right, top perspective view of another embodiment of a fiber optic cassette suitable for mounting on the main frame member of  FIG.  37   ; 
         FIG.  75    is a top view of the fiber optic cassette of  FIG.  74   ; 
         FIG.  76    is a bottom view of the fiber optic cassette of  FIG.  74   ; 
         FIG.  77    is a right side view of the fiber optic cassette of  FIG.  74   ; 
         FIG.  78    is a front, right, top exploded perspective view of the fiber optic cassette of  FIG.  74   ; 
         FIG.  79    illustrates a top view of the fiber optic cassette of  FIG.  74    with the cover removed to show the internal features thereof, the fiber optic cassette shown with a first example cable routing configuration within the cassette; 
         FIG.  80    illustrates the fiber optic cassette of  FIG.  79    with a second example cable routing configuration within the cassette; 
         FIG.  81    illustrates the fiber optic cassette of  FIG.  79    with a third example cable routing configuration within the cassette; 
         FIG.  82    illustrates the fiber optic cassette of  FIG.  79    with a fourth example cable routing configuration within the cassette; 
         FIG.  83    illustrates the fiber optic cassette of  FIG.  79    with a fifth example cable routing configuration within the cassette; 
         FIG.  84    illustrates the fiber optic cassette of  FIG.  79    with a sixth example cable routing configuration within the cassette; 
         FIG.  85    illustrates the fiber optic cassette of  FIG.  79    with a seventh example cable routing configuration within the cassette; 
         FIG.  86    illustrates the fiber optic cassette of  FIG.  79    with an eighth example cable routing configuration within the cassette; 
         FIG.  87    illustrates the fiber optic cassette of  FIG.  79    with a ninth example cable routing configuration within the cassette; 
         FIG.  88    illustrates the fiber optic cassette of  FIG.  79    with a tenth example cable routing configuration within the cassette; 
         FIG.  89    illustrates the fiber optic cassette of  FIG.  79    with an eleventh example cable routing configuration within the cassette; 
         FIG.  90    is a front, right, top perspective view of another embodiment of a fiber optic cassette suitable for mounting on the main frame member of  FIG.  37   ; 
         FIG.  91    is a top view of the fiber optic cassette of  FIG.  90   ; 
         FIG.  92    is a bottom view of the fiber optic cassette of  FIG.  90   ; 
         FIG.  93    is a front view of the fiber optic cassette of  FIG.  90   ; 
         FIG.  94    is a rear view of the fiber optic cassette of  FIG.  90   ; 
         FIG.  95    is a right side view of the fiber optic cassette of  FIG.  90   ; 
         FIG.  96    is a left side view of the fiber optic cassette of  FIG.  90   ; 
         FIG.  97    is a front, right, top exploded perspective view of the fiber optic cassette of  FIG.  90   ; 
         FIG.  98    illustrates a top view of the fiber optic cassette of  FIG.  90    with the cover removed to show the internal features thereof, the fiber optic cassette shown with the MPO connectors removed from the fiber optic cassette; 
         FIG.  99    illustrates the fiber optic cassette of  FIG.  98    with the MPO connectors mounted to the fiber optic cassette; and 
         FIG.  100    illustrates a rear perspective view of a telecommunications rack configured to house a plurality of distribution panels similar to the distribution panel of  FIG.  24   , the telecommunications rack shown with one of the distribution panels mounted thereon and with an example cable routing configuration around portions of the rack; 
         FIG.  101    illustrates an example cable routing configuration for a fiber optic cassette similar to the cassette of  FIGS.  50 - 71    mounted on the panel of  FIG.  100   , the cable routing shown for a rear side of the rack; 
         FIG.  102    illustrates an example cable routing configuration for the telecommunications rack of  FIG.  100    for an incoming cable routed to the modules located on the rack, the cable incoming from the top of the rack; 
         FIG.  102 A  is a close up view of a portion of the cable routing configuration of  FIG.  102   ; 
         FIG.  102 B  is a close up view of another portion of the cable routing configuration of  FIG.  102   ; 
         FIG.  103    illustrates an example cable routing configuration for the telecommunications rack of  FIG.  100    for an incoming cable routed to the modules located on the rack, the cable incoming from the bottom of the rack; 
         FIG.  103 A  is a close up view of a portion of the cable routing configuration of  FIG.  103   ; 
         FIG.  103 B  is a close up view of another portion of the cable routing configuration of  FIG.  103   ; 
         FIG.  104    illustrates an example cable routing configuration for the telecommunications rack of  FIG.  100    for an incoming patch cord routed to the modules located on the rack, the patch cord incoming from the top of the rack; 
         FIG.  104 A  is a close up view of a portion of the cable routing configuration of  FIG.  104   ; 
         FIG.  104 B  is a close up view of another portion of the cable routing configuration of  FIG.  104   ; 
         FIG.  105    illustrates an example cable routing configuration for the telecommunications rack of  FIG.  100    for an incoming cable that leads to a splice chassis of the rack, the cable incoming from the top of the rack; 
         FIG.  106    illustrates an example cable routing configuration for the telecommunications rack of  FIG.  100    for an incoming cable that leads to a splice chassis of the rack, the cable incoming from the bottom of the rack; 
         FIG.  107    illustrates an example cable routing configuration within the rack for a pigtail cable extending from the modules of the telecommunications rack of  FIG.  100    to a splice chassis of the rack; 
         FIG.  107 A  is a close up view of a portion of the cable routing configuration of  FIG.  107   ; 
         FIG.  107 B  is a close up view of another portion of the cable routing configuration of  FIG.  107   ; 
         FIG.  108    illustrates a front perspective view of the telecommunications rack of  FIG.  100   , showing an example cable routing configuration at the front side of the rack, the cables extending from the modules mounted on a distribution panel similar to the distribution panel of  FIG.  24    which is mounted on the rack; 
         FIG.  109    illustrates an example cable routing configuration for a fiber optic cassette mounted on the panel of  FIG.  100   , the cable routing shown for a front side of the rack; 
         FIG.  110    illustrates an example cable routing configuration for cross-connect cabling within the same rack from one module on a panel to another module on another panel within the rack, the modules located on opposite sides of the rack; 
         FIG.  111    illustrates an example cable routing configuration for cross-connect cabling within the same rack similar to that shown in  FIG.  110   , however, between modules on the right side of the rack and between modules on the left side of the rack; 
         FIG.  112    illustrates an example cable routing configuration for cross-connect cabling between two of the telecommunications racks of  FIG.  100   ; 
         FIG.  113    illustrates an example cable routing configuration for an interconnect routing on a single frame, wherein incoming patch cords are routed to the modules located on the rack, the patch cords incoming from the top of the rack; 
         FIG.  114    illustrates certain example methods of managing cable slack for cables routed within the rack of  FIG.  100   ; 
         FIG.  115    is a perspective view of a bottom portion of the telecommunications rack of  FIG.  100    including a sliding frame configured to hold telecommunications equipment such as splice cassettes; 
         FIG.  116    is an isolated view of a sliding frame of  FIG.  115    with the splice cassettes removed for ease in viewing; 
         FIG.  117    is a top plan view of the telecommunications rack shown in  FIG.  115    taken along a lateral cross-section so that the splice area is visible with the frame slid out to show the storage region; 
         FIG.  118    is a schematic diagram showing example cables routed through the storage area and sliding frame of  FIG.  117   ; 
         FIG.  119    is a front perspective view of another embodiment of a telecommunications rack configured to house a plurality of distribution panels similar to the distribution panel of  FIG.  24   , the telecommunications rack including features similar to those of the telecommunications rack shown in  FIGS.  100 - 118   ; 
         FIG.  120    is a rear perspective view of the telecommunications rack of  FIG.  119   ; 
         FIG.  121    is a front view of the telecommunications rack of  FIG.  119   , the rack shown with an example cable routing configuration at the front side of the rack for an incoming cable routed from the upper trough of the rack to the modules located on the rack; 
         FIG.  122    is a top view of the telecommunications rack of  FIG.  121   , shown with the cable leading from the upper trough of the rack downwardly; 
         FIG.  123    is a rear view of the telecommunications rack of  FIG.  119   , the rack shown with an example cable routing configuration at the rear side of the rack for an incoming cable routed to the modules located on the rack, the cable incoming from the top of the rack; 
         FIG.  124    is a left side view of the telecommunications rack of  FIG.  119   , wherein it should be noted that the terms “right” and “left” are used to refer to the right and left sides of the rack when looking at the rack from a rear view thereof (i.e. when a person is standing at the rear of the rack); 
         FIG.  125    is a perspective view illustrating two of the telecommunications racks of  FIG.  119    coupled with a cross-aisle trough for routing cabling from one telecommunications rack to another; and 
         FIG.  126    illustrates the telecommunications racks of  FIG.  125    from a top view. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to examples of inventive aspects of the present disclosure which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
     A high-density distribution frame  10  is illustrated in  FIGS.  1 - 7   . The fiber distribution frame  10  defines a front side  12 , a rear side  14 , a right side  16 , and a left side  18 . The fiber distribution frame  10  includes a plurality of fiber optic connection modules  20  mounted thereon in a stacked arrangement. As will be described in further detail below, each of the connection modules  20  is separately slidable with respect to the frame  10  between a retracted position and an extended position for the purpose of accessing the fiber optic equipment located in or on the modules  20 . The connection modules  20  are slidably extendable from a neutral position on the distribution frame  10  to an extended position in either the front or the back directions. Thus, if the fiber optic connection locations within the module  20  need to be accessed from the rear  14  of the distribution frame  10 , the modules  20  can be slidably extended from the neutral position toward the rear  14  of the frame  10 . Similarly, if the fiber optic connection locations within the module  20  need to be accessed from the front  12  of the distribution frame  10 , the modules  20  can be slidably extended from the neutral position toward the front  12  of the frame  10 . As will be explained in further detail below, the modules  20  include a latching arrangement configured to lock or position the modules  20  in the neutral retracted position and allow the modules  20  to be unlocked for slidable movement in either direction. 
     Still referring to  FIGS.  1 - 7   , as will be explained in further detail, the high-density fiber distribution frame  10  includes cable management features located on the left side  18  of the frame  10  and also generally underneath the stack of connection modules  20  for guiding input cables toward the frame  10  and guiding output cables away from the frame  10 . In the present application, although the connection modules  20  are shown and described as being mounted on a fiber distribution frame such as that shown in  FIGS.  1 - 7   , the distribution frame  10  is only one example of a piece of fiber optic equipment to which such modules  20  may be mounted. It should be noted that the high-density fiber distribution frame  10  described herein may be used in a stacked arrangement in a telecommunications rack such as that described in U.S. Pat. No. 6,591,051, incorporated herein by reference in its entirety. Such a telecommunications rack  300  is also shown in  FIG.  24    with a plurality of prior art distribution frames or blocks  302  mounted thereon in a stacked arrangement. The example rack defines a vertical cable path  304  with cable management structures  306  for leading cables away from and toward the distribution frames/blocks  302 . 
     Now referring to  FIGS.  8  and  9   , one of the slidable fiber optic connection modules  20  is shown in isolation. The connection module  20  is shown in the neutral (retracted) position. The connection module  20  utilizes a three-piece slide assembly  22  that includes a rack and pinion arrangement allowing the connection module  20  to be slidable between the retracted and extended positions. By using a three-piece slide assembly  22  with a rack and pinion arrangement, a center member  24  of the slide assembly  22  moves with respect to both a main frame member  26  and a rack mount member  28  of the connection module  20 . Due to the gear arrangement, the center member  24  moves at half the linear speed that the main frame member  26  moves with respect to the stationary rack mount member  28 . Portions of the center member  24  of the slide assembly  22  may be used as handles for pulling and pushing the main frame member  26  between the extended and retracted positions. Since the center member  24  also moves while main frame member  26  is moving (at half the linear speed of the main frame member  26 ), the module  20  is configured to manage the slack in the cables routed through the module  20 . The slide assembly  22  is configured such that when the connection module  20  is moved to either the front or the back extended position, cables extending from the main frame member  26 , around radius limiters defined at the two ends of the center member  24 , can maintain the same path length and are not stressed or pulled during the travel of the main frame member  26 . Also, when the module  20  is being slid from the extended position to the neutral position, the slide assembly  22  allows the main frame member  26  to move in the same direction as the center member  24  (and the radius limiters located on ends of the center member  24 ), providing management of any slack in the cables routed through the module  20 . 
     Still referring to  FIGS.  8 - 9   , as discussed, the connection module  20  includes a main frame member  26 . The main frame member  26  is configured to provide connection locations  30  for the module  20 . For each main frame member  26 , at each of the right and left sides  32 ,  34  thereof, the main frame member  26  defines a dove-tail shaped longitudinal protrusion  36 . At the left side  34  of the main frame member  26 , the dove-tail shaped longitudinal protrusion  36  slides within a matching longitudinal groove  38  defined on the right side  40  of the center member  24 . For each main frame member  26 , at the right side  32  of the main frame member  26 , the dove-tail shaped longitudinal protrusion  36  slides within one of a plurality of tracks  42  defined on the right side  16  of the high-density distribution frame  10 . 
     As will be described in further detail below, the center member  24  slides between the rack mount member  28  (which may be stationarily mounted to a device such as the distribution frame  10 ) and the main frame member  26 . The center member  24  defines a similar second longitudinal groove  44  on the left side  46  thereof that slides over a longitudinal protrusion  48  defined by the stationarily mounted rack mount member  28  such that the center member  24  can slide between the main frame member  26  and the rack mount member  28 . 
     Each of the longitudinal protrusion  36  of the main frame member  26  and the longitudinal protrusion  48  of rack mount member  28  defines a rack. The racks  50 ,  52  in each of these members, respectively, meshes at the same time with a gear wheel  54  that is located within the center member  24 . With such a rack and pinion arrangement of the slide assembly  22 , synchronized slidable movement of the center member  24  and the main frame member  26  is established, while the rack mount member  28  stays stationary. 
     Thus, by pulling and pushing the center member  24 , a user can slidably pull and push the main frame member  26  at the same time at twice the speed of the center member  24 . Conversely, by moving the main frame member  26 , the center member  24  also moves in the same direction as the main frame member  26 , at half the speed of the main frame member  26  relative to the stationary rack mount member  28 . 
     As such, the slide assembly  22  provides synchronized slidable movement for radius limiters located on the ends of the center member  24  relative to the main frame member  26 . As noted above, the synchronized movement of the radius limiters of the center member  24  and the main frame member  26  ensures that cables routed from the connection locations  30  of the main frame member  26  do not bend too sharply when the main frame member  26  is being extended or retracted. If the cables were to bend too sharply or if the cables were stressed or pulled, loss of signal strength or loss of transmission may occur. 
     The rack mount member  28 , in the depicted embodiment, includes fastener openings  54  for receiving fasteners for stationarily mounting the rack mount member  28  to a piece of telecommunications device such as the high distribution frame  10  shown in  FIGS.  1 - 7   . 
     Referring specifically now to  FIGS.  10 - 15   , the center member  24  that is used to pull and push the main frame member  26  includes a base member  60 , a latch rod  62 , and a cover member  64 . The cover member  64  is configured to be coupled to the base member  60  with snap-fit connections, capturing the latch rod  62  therewithin. 
     When the center member  24  is initially in the neutral retracted state, it needs to be unlatched before it can be pulled or pushed. The latch rod  62  is configured to unlatch and latch the center member  24  with respect to the stationary rack mount member  28 . 
     The latch rod  62  includes a front end  66  and a rear end  68  and a length  70  extending therebetween. At the front and rear ends  66 ,  68  thereof, the latch rod  62  includes a handle  72 . Each handle  72  is used to pull or push the center member  24 . At about midway along the length  70  of the latch rod  62 , a gear housing  74  is located. The gear wheel  76  of the rack/pinion arrangement is located within the gear housing  74 . As noted above, the gear wheel  76  includes gear teeth that are configured to simultaneously mesh with a first rack  52  provided in the rack mount member  28  and a second rack  50  provided on the main frame member  26 . Adjacent both the front and rear sides of the gear wheel  76  is located a latching arrangement  80 . The latching arrangement  80  includes a floating plate  82  defining a pin  84  therethrough. The pin  84  of the floating plate  82  resides in a groove  86  defined on the latch rod  62 . The groove  86  defines an upside down V-shape configuration and has a middle peak point  88  and lower end points  90  at either side. When the pin  84  is positioned at the middle peak point  88 , the plate  82  is at an upward position and is located within a notch  92  defined on the rack mount member  28  (please see  FIG.  22   ). When the latch rod  62  is pulled or pushed, the pin  84  of the floating plate  82  moves downwardly along the groove  86  (having an upside down V-shape). The movement of the plate  82  downwardly clears the plate  82  from the notch  92  and the center member  24  can now be slidably pulled or pushed with respect to the rack mount member  28 . The floating plate  82  is spring biased upwardly such that when the center member  24  is moved toward the neutral position, the plate  82  moves upwardly into the notch  92  of the rack mount member  28  when the plate  82  aligns with the notch  92 , locking the center member  24  in place. Although only one of the floating plates  82  is shown in  FIG.  11   , the latch rod  62  includes a similar arrangement on both the front side and the rear side of the center gear wheel  76 . Thus, the first rack  52  defined by the rack mount member  28  also includes notches  92  on both sides of the center gear  76 . 
     As noted previously, once the floating plate  82  clears the notch  92 , the gear  76  meshes with the racks  52 ,  50  defined on the rack mount member  28  and the main frame member  26  to start moving the main frame member  26  relative to both the center member  24  (at twice the speed of the center member  24 ) and the stationary rack mount member  28 . It should be noted that when the handle  72  is pulled or pushed to unlock the module  20  and to move the pin  84  of the floating plate  82  from the peak  88  of the groove  86  toward either side of the groove  86 , the gear wheel  76  rotates slightly to move the main frame member  26  in the same direction as the center member  24 . When the pin  84  of the floating plate  82  reaches either of the lower ends  90  of the upside down V-shaped groove  86 , the floating plate  82  is now completely out the notch  92  and the module  20  can freely slide. 
     At each of the front and rear ends  94 ,  96  of the center member  24  is located a cable management structure  98 . The cable management structure  98  defines a spool  100  and a pair of cable management fingers  102 . Along with the handle  72  and the spool  100 , the cable management fingers  102  define a cable path  104  for fiber optic cables coming from or going to the main frame member  26 . Once cables are lead around the spool  100 , they are guided to the left side  18  of the high density distribution frame  10  to cable management structures found on the left side  18  of the frame  10 . 
     It should be noted that cables from both the front and the back ends  25 ,  27  of the main frame member  26  are guided around a spool  100  located at each of the ends  94 ,  96  of the center member  24  and lead to the left side  18  of the distribution frame  10 . 
     When the center member  24  moves, moving the main frame member  26  therewith, cables coming from the main frame member  26  that are routed around the spools  100  at each end  94 ,  96  of the center member  24  maintain a generally uniform length as they extend to the left side  18  of the distribution frame  10 . For example, while the front end  25  of the main frame member  26  is moving toward the front  12  of the distribution frame  10 , the front end  94  of the center member  24  and thus the spool  100  located at the front end  94  of the center member  24  also moves simultaneously with the main frame member  26 , taking up any slack in the cable. Similarly, at the same time, while the rear end  27  of the main frame member  26  is moving toward the front  12  of the distribution frame  10 , the rear end of the center member  26  and thus the spool  100  located at the rear end  96  of the center member  24  moves simultaneously in the same direction, reducing any pull or tension on the cable routed through the main frame member  26 . The slide assembly  22  functions in the same manner when the main frame member  26  is moved in the rearward direction for accessing connection locations  30  from a rear side  14  of the distribution frame  10 . 
     The interaction of the gear  76  within the center member  24  and the first rack  52  on the rack mount member  28  and the second rack  50  on the main frame member  26  is illustrated in  FIGS.  20  and  21   . 
     Referring to  FIG.  10   , tabs  110  located on the rack mount member  28  flex to fit within notches  112  defined on the cover member  64  of the center member  24  to provide stop points to indicate to a user a neutral position for the slide assembly  22 . 
     Even though the base member  60  and the cover member  64  of the center member  24  are depicted as being coupled together with snap-fit interlocks via tabs  65  and recesses  67 , other types of coupling arrangements may be used. For example, threaded fasteners may be used. 
     Referring back to  FIGS.  8  and  9   , the main frame member  26  is illustrated. The main frame member  26  includes a right wall  120  and a left wall  122 . The right wall  120  defines the longitudinal protrusion  36  allowing the main frame member  26  to be slidably coupled to the right side  16  of the distribution frame  10 . The left wall  122  includes a similar longitudinal protrusion  36  for sliding within the center member  24 . As noted above, each of the longitudinal protrusions  36  of the right wall  120  and the left wall  122  defines a dovetail shaped profile for slidable insertion into dovetail shaped longitudinal groove  38  of the center member  24  and longitudinal track  42  defined on the right side  16  of the distribution frame  10  as shown in  FIGS.  1  and  2   . The dovetail shaped profiles provide for longitudinal slidable coupling between each center member  24  and main frame member  26  and each main frame member  26  and the distribution frame  10  while preventing uncoupling in a direction perpendicular to the sliding direction. 
     The longitudinal protrusion  36  on the left wall  122  of the main frame member  26  also defines the second rack  50  for meshing with the gear  76  located within the center member  24 . 
     As discussed previously, by meshing with both the first rack  52  on the rack mount member  28  and the second rack  50  on the main frame member  26  at the same time, the gear  76  located on the center member  24  allows the center member  24  to move at half linear speed simultaneously with the main frame member  26  in the same direction. 
     The main frame member  26  is configured to provide fiber optic connection locations  30  for the connection module  20 . By stacking a plurality of the modules  20  on a distribution frame  10 , density of connections for fiber optic transmission can be increased and the slidability of the modules  20  in either the front direction or the back direction provides for easy access at both the front  12  and the rear  14  of the distribution frame  10 . As shown in  FIGS.  8 - 9   , the depicted version of the main frame member  26  includes a mount  130  for mounting fiber optic adapters  132  which define the fiber optic connection locations  30  in this embodiment of the module  20 . Specifically, in the module  20  shown and described in the present application, the fiber optic connection locations  30  are defined by adapters  132  having an LC type footprint. In the depicted embodiments, twenty-four LC adapters  132  are mounted to the mount  130  via fasteners through fastener openings  134  defined on the mount  130 . In the high density distribution frame  10  shown in  FIGS.  1 - 7   , twelve slidable modules  20  are mounted on the frame  10 . 
     It should be noted that other standards of fiber optic adapters  132  (such as SC adapters) can be mounted to the mount  130 . Fiber optic adapters  132  are only one type of fiber optic equipment that provides connection locations  30  for the module  20  and the module  20  can be used with other types of fiber optic equipment. For example, equipment such as fiber optic splitters, couplers, multiplexers/demultiplexers, or other types of equipment wherein cables may be routed away from the connection locations  30  may be housed on the main frame member  26 . 
     If fiber optic adapters are used, the connection locations may be defined by adapters individually mounted in the mount or may be defined by blocks that include integrally formed adapters. In other embodiments, the connection locations may be in the form of a cassette that includes fiber optic adapters on one side wherein the opposite side either has a multi-fiber connector or a cable extending outwardly therefrom, as described in further detail in U.S. Pat. No. 9,535,229, incorporated herein by reference in its entirety. 
     As long as plurality of fiber optic cables or even a single fiber optic cable is being routed from the main frame member, around the radius limiters  100  of the center member  24 , toward the left side  18  of the distribution frame  10 , the slide assembly  22  of the module  20  provides access to those fiber optic terminations while managing the cable slack to prevent pinching and preventing pulling or stressing of the cables. 
     The left wall  122  of the main frame member  26  defines a cable management structure  136  adjacent the front side  25  of the main frame member  26 . A second cable management structure  138  is also defined between the left wall  122  and the rear wall  123  of the main frame member  26  adjacent the rear  27  of the main frame member  26 . Each of the first and second cable management structures  136 ,  138  includes a radius limiter  140 ,  142  and a pair of cable management fingers  144  for guiding cables from connection locations  30  toward ends  94 ,  96  of the center member  24 . 
     The front side  25  of the main frame member  26  includes a plate  150  that is pivotably disposed. The plate  150  is configured to pivot downwardly by gravity when the module  20  has been extended forwardly and pivot upwardly by contact when the module  20  has been retracted to the neutral position. The plate  150 , by pivoting downwardly, provides easier access to the connection locations  30  when the module  20  is in the forward extended position. 
     As noted above, after the cables coming from the connection locations  30  have been guided from the main frame member  26  around the spools  100  located at the ends  94 ,  96  of the center member  24 , they are lead to the left side  18  of the distribution frame  10 . 
     The distribution frame  10  defines a plurality of cable management fingers  170 ,  172 , respectively, adjacent both the front  12  and the rear  14  at the left side  18  of the frame  10  for guiding cables downwardly/upwardly depending upon whether the cables are input or output cables. 
     After or before the cable management fingers  170 ,  172  (depending upon whether the cables are designated as input cables or output cables), the cables are routed through a trough system  180  located generally underneath the stacked modules  20 . 
     Although an example cable routing will be described herein, it shall be understood that the routing used within the distribution frame  10  is only one example and that the distribution frame  10  may be used in a different manner. 
     According to one example use of the distribution frame  10 , the rear sides  131  of the adapters  132  located within the module  20  may be used for connecting input signals and the front sides  133  of the adapters  132  may be used for output signals. According to the example routing, the cables carrying the input signals may be routed upwardly from the lower ramp  182  shown in  FIG.  3    into the first horizontal trough  184  defined underneath the stacked modules  20 . After going around a radius limiter  186  located adjacent the rear side  14  of the distribution frame  10 , the cables are lead around a pair of management structures  188  located at the rear, left side  14 / 18  of the distribution frame  10  and up and around the cable management fingers  172  located adjacent the rear, left side  14 / 18  of the distribution frame  10 . After the cables are passed around the cable management fingers  172 , the cables may be guided around the spools  100  located at the back ends  96  of the center members  24  and into the main frame members  26  of the modules  20 . 
     The cables carrying the output signal may be lead out of the main frame members  26  and around the spools  100  at the front ends  94  of the center members  24 . After going over the cable management fingers  170  adjacent the front, left side  12 / 18  of the distribution frame  10 , cables carrying the output signal can go around a pair of management structures  190  located at the front, left side  12 / 18  of the distribution frame  10 . From the pair of management structures  190 , the output cables can either be directly lead downwardly through a vertical path  192  defined at the left side  18  of the distribution frame  10  or can be lead around a radius limiter  194  located at the front side  12  of the distribution frame  10  into a second horizontal trough  196  as shown in  FIGS.  1 - 3   . Within the second horizontal trough  196  that extends underneath the stacked modules  20 , the output cables can go diagonally from the front, left side  12 / 18  of the frame  10  to the rear, right side  14 / 16  of the frame  10  for further connection. 
     As noted above, the distribution frame  10  may be modified to reverse the input and output cables and change the cable management paths thereof accordingly. 
     In accordance with some aspects, certain types of adapters  132  may be configured to collect physical layer information from one or more fiber optic connectors  135  received thereat. For example, as shown in  FIG.  23   , certain types of adapter modules  132  may include a body  200  configured to hold one or more media reading interfaces  220  that are configured to engage memory contacts on the fiber optic connectors  135 . One or more media reading interfaces  220  may be positioned in the adapter body  200 . In certain implementations, the adapter body  200  defines slots  210  extending between an exterior of the adapter body  200  and an internal passage in which the ferrules of the connectors  135  are received. 
     Certain types of media reading interfaces  220  include one or more contact members  221  that are positioned in the slots  210 . As shown in  FIG.  23   , a portion of each contact member  221  extends into a respective one of the passages to engage memory contacts on a fiber optic connector  135 . Another portion of each contact member  221  also extends out of the slot  210  to contact a circuit board  230 . Portions of the main frame member  26  may define conductive paths that are configured to connect the media reading interfaces  220  of the adapter  132  with a master circuit board. The master circuit board may include or connect (e.g., over a network) to a processing unit that is configured to manage physical layer information obtained by the media reading interfaces. 
     Example adapters having media reading interfaces and example fiber optic connectors having suitable memory storage and memory contacts are shown in U.S. Pat. No. 8,690,593, the disclosure of which is hereby incorporated herein by reference. 
     Referring now to  FIGS.  25 - 36   , another embodiment of a slidable fiber optic connection module  300  having features that are examples of inventive aspects in accordance with the present disclosure is illustrated. 
     In  FIG.  25   , a plurality of the slidable fiber optic connection modules  300  are shown in a stacked arrangement on a rack mount telecommunications panel  302  (e.g., a 19-inch panel in the depicted example). As noted for previous embodiments, even though the connection modules  300  are shown and described as being mounted on a rack mount telecommunications panel such as that shown in  FIG.  25   , the panel  302  is only one example of a piece of fiber optic equipment to which such modules  300  may be mounted and other telecommunications equipment may be used. The rack mount panel  302  will be used to illustrate and describe the inventive aspects of the connection modules  300 . 
     The telecommunications panel  302  defines an open front end  304 , an open rear end  306 , a right side  308  defined by a right wall  310 , a left side  312  defined by a left wall  314 , a top side  316  defined by a top wall  318 , and a bottom side  320  defined by a bottom wall  322 . The panel  302  includes mounting brackets  324  attached to the right and left walls  310 ,  314  for mounting the panel  302  to a standard telecommunications rack. The panel  302 , in the depicted embodiment, includes a center divider  326  that splits the panel  302  into a right half  328  and a left half  330 . 
     In the given embodiment, the arrangement of the modules  300  on the right half  328  of the panel  302  mirrors the arrangement on the left half  330  of the panel  302 . As such, in the depicted example, panel  302  includes twelve modules  300  in a stacked arrangement from the bottom to the top side of the panel  302  at the left half  330  of the panel  302  and twelve modules  300  in a stacked arrangement at the right half  328  of the panel  302 . 
     As will be described in further detail below, the connection modules  300  include certain features that are similar to the modules  20  describe above. However, the connection modules  300  are configured such that if connection locations of the modules need to be accessed from a front end  304  of the panel  302 , a front handle  332  must be pulled (and pushed in retraction of the module  300 ) from the front end  304  of the panel  302  and if the connection locations of the modules  300  need to be accessed from a rear end  306  of the panel  302 , a rear handle  334  of the connection modules  300  must be pulled (and pushed in retraction of the module  300 ) from the rear end  306  of the panel  302 . As will be discussed in further detail below, each module  300  provides stop features such that the front handle  332  cannot be used to push the module  300  all the way to the rear end  306  where it can be accessed from the rear end  306  and that the rear handle  334  cannot be used to push the module  300  all the way to the front end  304  where it can be accessed from the front end  304  of the panel. Each of the front and rear handles  332 ,  334  can only be used to move the modules  300  from a neutral position to their respective sides and back to the neutral position. 
       FIGS.  26 - 32    illustrate a module  300  in isolation. Similar to the modules  20  described above (with certain differences), each module  300  utilizes a three-piece slide assembly  336  that includes a rack and pinion arrangement  338  allowing the connection module  300  to be slidable between a retracted neutral and an extended position. By using a three-piece slide assembly  336  with a rack and pinion arrangement  338 , a center member  340  of the slide assembly  336  moves with respect to both a main frame member  342  and a rack mount member  344  of the connection module  300 . As discussed with respect to the previous embodiment  20 , due to the gear arrangement  338 , the center member  340  moves at half the linear speed that the main frame member  342  moves with respect to the stationary rack mount member  344 . 
     Since the center member  340  moves while main frame member  342  is moving (at half the linear speed of the main frame member  342 ), the module  300  is configured to manage the slack in the cables routed through the module  300  as discussed previously. 
     The main frame member  342  of the module  300  is configured to provide connection locations  346  for the module  300 . Referring now to each module  300  that is located at the left half  330  of the rack mount telecommunications panel  302 , for example, the main frame member  342  of the module  300  defines a dove-tail shaped longitudinal protrusion  348  at each of the right and left sides  350 ,  352  thereof. For those modules  300  that are at the left half  330  of the rack mount panel  302 , at the left side  352  of the main frame member  342 , the dove-tail shaped longitudinal protrusion  348  slides within a matching longitudinal groove  354  defined on the right side  356  of the center member  340 . At the right side  350  of each main frame member  342 , the dove-tail shaped longitudinal protrusion  348  slides within one of a plurality of tracks  358  defined by the center divider  326  of the rack mount telecommunications panel  302 . This configuration is reversed or mirrored for modules  300  that are at the right half  328  of the telecommunications panel  302 . As such, the details of the modules  300  at the right half  328  of the telecommunications panel  302  will not be discussed further, with the understanding that the configuration and the operation of the modules  300  on the right half  328  of the panel  302  are similar to the configuration and the operation of the modules  300  on the left half  330  of the panel  302 . 
     Regarding the modules  300  at the left half  330  of the panel  302 , as in previous modules  20  described above, the center member  340  slides between the rack mount member  344  (which is stationarily mounted to the panel  302 ) and the main frame member  342 . The center member  340  defines a similar second longitudinal groove  360  on the left side  362  thereof that slides over a longitudinal protrusion  364  defined by the stationarily mounted rack mount member  344  such that the center member  340  can slide between the main frame member  342  and the rack mount member  344 . 
     Similar to the previous embodiments discussed, each of the longitudinal protrusion  348  of the main frame member  342  and the longitudinal protrusion  364  of rack mount member  344  defines a rack. The racks  370 ,  372  in each of these members, respectively, meshes at the same time with a gear wheel  374  that is located within the center member  340 . With such a rack and pinion arrangement  338  of the slide assembly  336 , synchronized slidable movement of the center member  340  and the main frame member  342  is established, while the rack mount member  344  stays stationary. 
     Thus, by pulling and pushing the center member  340 , a user can slidably pull and push the main frame member  342  at the same time at twice the speed of the center member  340 . Conversely, by moving the main frame member  342 , the center member  340  also moves in the same direction as the main frame member  342 , at half the speed of the main frame member  342  relative to the stationary rack mount member  344 . 
     The synchronized movement of radius limiters of the center member  340  and the main frame member  342  ensures that cables routed from the connection locations  346  of the main frame member  342  do not bend too sharply when the main frame member  342  is being extended from or returned to the neutral position. If the cables were to bend too sharply or if the cables were stressed or pulled, loss of signal strength or loss of transmission may occur. 
     In the depicted embodiment of the rack mount telecommunications panel  302 , the rack mount member  344  of the modules  300  and the panel  302  include complementary interlock features for mounting the rack mount members  344  to the telecommunications panel  302  with a snap-fit interlock. In the depicted embodiment, each rack mount member  344  defines a dove-tail shaped longitudinal protrusion  380  that is slidably inserted into a dove-tail shaped longitudinal groove  382  defined by each of the right and left walls  310 ,  314  of the telecommunications panel  302 . The longitudinal grooves  382  of the telecommunications panel  302  extend from the front side to the rear side of the panel  302  and are configured to receive the rack mount members  344  in a direction along a front to back direction. 
     Each rack mount member  344  also defines an elastically flexible cantilever arm  384  at the front and rear ends  386 ,  388  thereof, each configured to form a snap-fit interlock with the right and left walls  310 ,  314  of the panel. As shown in  FIG.  25   , when referring to, for example, the modules  300  on the right half  328  of the panel, when each rack mount member  344  is being slidably inserted into the longitudinal groove  382  of the panel  302  in a direction from the front side to the rear side of the panel  302 , the cantilever arm  384  that is at the rear  388  of the rack mount member  344  (the cantilever arm  384  that is located forwardly in the advancing direction) flexes slightly to allow the longitudinal protrusion  380  of the rack mount member  344  to slidably fit within the groove  382  of the panel  302 . When the rack mount member  344  has been slid all the way, the flexible arm  384  at the rear  388  flexes back to snap over a portion of the right wall  310  of the panel  302 . The flexible cantilever arm  384  at the front end  386  of the rack mount member  344  provides a stop and prevents further advancement of the rack mount member  344  within the longitudinal groove  382 . When removing the rack mount member  344  from the panel  302 , depending upon which direction the rack mount member  344  will be removed, one of the rear or front flexible arms  384  must be flexed outwardly to clear the panel  302  before the rack mount member  344  can be slid in an opposite direction. The same procedure for inserting and removing rack mount members  344  can be used for rack mount members  344  that are on the left half  330  of the panel  302 . It will also be noted that the rack mount members  344  that are used at the right side of the panel  302  can also be used on the left side of the panel  302  if they are flipped 180 degrees. 
     Referring specifically now to  FIGS.  29 - 32   , the configuration and the operation of the center member  340  of the modules  300  will be described. 
     Referring to a module  300  that is, for example, oriented to be located at the left half  330  of the rack mount panel  302 , the center member  340  of the module  300  includes a base member  390 , a cover member  392 , and a front latch rod  394  and a rear latch rod  396 . The cover member  392  is configured to be coupled to the base member  390  with snap-fit connections, capturing the front and rear latch rods  394 ,  396  therewithin. 
     When the center member  340  is initially in the neutral state in the panel  302 , it needs to be unlatched before it can be pulled to an extended state. As will be described in further detail, the front and rear latch rods  394 ,  396  are configured to cooperate in unlatching and latching the center member  340  with respect to the stationary rack mount member  344  for movement between the neutral position and the extended position. As also will be described in further detail, the front and rear latch rods  394 ,  396  also cooperate to ensure that the front handle  332  cannot be used to push the module  300  all the way to the rear end of the panel  302  where it can be accessed from the rear end and the rear handle  334  cannot be used to push the module  300  all the way to the front end of the panel  302  where it can be accessed from the front end and that each of the front and rear handles  332 ,  334  can only be used to move the modules  300  from a neutral position to their respective sides and back to the neutral position. 
     Still referring to  FIGS.  29 - 32   , the front latch rod  394  includes a front end  398  and a rear end  400 . At the front end  398  of the front latch rod  394  is the handle  332  that is used to pull the center member  340  from a neutral position to an extended position and is used to push the center member  340  from the extended position back to the neutral position. The handle  332  is positioned and slidably rides within a slot  402  defined at the front end  404  of the base  390  of the center member  340 . Similarly, the rear latch rod  396  also includes the handle  334  that is positioned and slidably rides within a slot  406  defined at the rear end  408  of the cover  392  of the center member  340 . The handles  332 ,  334 , as will be discussed in further detail below, are configured for unlatching the center member  340  from the rack mount member  344  for moving the center member  340  with respect to the rack mount member  344 . As will be described, for example, when the handle  332  at the front of the center member  340  is used to unlatch the center member  340 , the handle  332  moves the front latch rod  394  slightly forwardly with respect to the base  390  of the center member  340  in freeing up the center member  340  from the rack mount member  344  to move the center member  340 . When the handle  332  is used to unlatch and push the center member  340  back to the neutral position, the handle  332  also moves the front latch  394  slightly in the rearward direction in freeing up the center member  340  from the rack mount member  344  to move the center member  340 . 
     As shown in  FIG.  29   , at the rear end  400  of the front latch rod  394  is a crescent shaped cam groove  412 . The cam groove  412  is configured to impart movement to a floating plate  414  that includes a pin  416  extending therethrough. The floating plate  414  is axially fixed with respect to the base  390  of the center member  340 . The floating plate  414  resides and is configured to slidably ride within a slot  418  (similar to slot  446  on the base member  390  that receives another floating plate  426  as shown in  FIG.  29   ) defined on the base  390  of the center member  340  along a direction extending between left and right. The floating plate  414  is constrained from moving front or back with respect to the base  390  of the center member  340  due to the slot  418 . 
     The pin  416  of the floating plate  414  is configured to slide within the cam groove  412  such that floating plate  414  can move axially with respect to the front latch rod  394  and also in a direction from right to left with respect to the front latch rod  394 . 
     Since the floating plate  414  is constrained axially with respect to the base  390  of the center member  340  along a front to back direction by being housed within the slot  418 , any movement of the base  390  of the center member  340  moves the floating plate  414  axially in the same amount. As noted above, the front latch rod  394  is configured so that it can move or float with respect to the base  390  to a certain extent to cam the float plate  414  out of engagement with the rack mount member  344 . And, any axial movement of the floating plate  414  with respect to the front latch rod  394  occurs within the cam groove  412  of the front latch rod  394 , wherein the floating plate  414  is always constrained from moving axially with respect to the base  390  due to being housed in the slot  418 . 
     The rear latch rod  396  includes a similar configuration to the front latch rod  394 . The rear latch rod  396  also includes the handle  334  at a rear end  420  and a cam groove  422  adjacent a front end  424  thereof. The rear latch rod  396  includes a floating plate  426  with a pin  428  extending therethrough that allow the rear latch rod  396  to act in a similar fashion to the front latch rod  394 . 
     The base  390  of the center member  340  also defines a gear housing  430 . The gear wheel  374  of the rack/pinion arrangement  338  is located within the gear housing  430 . As noted above, the gear wheel  374  includes gear teeth that are configured to simultaneously mesh with a first rack  372  provided in the rack mount member  344  and a second rack  370  provided on the main frame member  342 . 
     As shown in  FIGS.  29 - 32   , the rack mount member  344  defines a front notch  432 , a rear notch  434 , and an elongated middle notch  436 . The notches  432 ,  434 ,  436  of the rack mount member  344  are configured to interact with the floating plates  414 ,  426  of the front and rear latch rods  394 ,  396  in allowing movement of the center member  340  of the module  300  with respect to the rack mounting member  344 , as described below. 
     When the center member  340  (and thus the module  300 ) is in the neutral position, the floating plate  414  of the front latch rod  394  is positioned at a front edge  438  of the elongate middle notch  436  and the floating plate  426  of the rear latch rod  396  is positioned at a rear edge  440  of the elongate middle notch  436  (please see  FIGS.  30  and  30 A ). At this point, both of the floating plates  414 ,  426  are positioned at the peaks  442  of the cam grooves  412 ,  422 . It should be noted that the front and rear latching rods  394 ,  396  can be spring loaded to position the floating plates  414 ,  426  at the peaks  442  of the cam grooves  412 ,  422  as long as the floating plates  414 ,  426  have the clearance to move into the notches  432 ,  434 ,  436  defined on the rack mount member  344 . In one example embodiment, a spring can engage the floating plates  414 ,  426  directly and bias the plates  414 ,  426  in a direction from the right to left to cause the plates  414 ,  426  to fit into the notches  432 ,  434 ,  436  when the plates  414 ,  426  are aligned with any of the notches  432 ,  434 ,  436 . In other embodiments, springs could be positioned axially within the front and rear latch rods  394 ,  396  to cause the latch rods  394 ,  396  to move until the latch rods  394 ,  396  position the floating plates  414 ,  426  into any of the nearby notches  432 ,  434 ,  436 . 
     Still referring to  FIGS.  29 ,  30  and  30 A , in the neutral position, when both of the floating plates  414 ,  426  are positioned within the middle notch  436 , pulling on the front handle  332  starts to move the floating plate  414  from left to right out of the elongate middle notch  436  of the rack mount member  344 . This is caused by the pin  416  encountering the cam profile of the cam groove  412  and moving to a lower point along the groove  412  at the rear end  444  of the groove  412 . At this point, the front latch rod  394  has floated slightly forwardly with respect to the base  390  of the center member  340 . 
     As the pin  416  of the floating plate  414  contacts the rear end  444  of the cam groove  412 , the front latch  394  stops floating within the base  390  and starts moving the base  390  therewith. The rear latch rod  396 , which is axially engaged with the base  390  of the center member  340  through the floating plate  426  within a slot  446 , starts moving with the base  390 . Since the rear floating plate  426  is riding along the elongate notch  436 , the pin  428  of the rear floating plate  426  simply stays at the peak  442  of the rear cam groove  422 . 
     Referring now to  FIGS.  29 ,  31 , and  31 A , when the floating plate  414  of the front latch rod  394  encounters the front notch  432  of the rack mount member  344 , the plate  414  is spring biased into the notch  432 , providing a stop point to indicate to a user that the module  300  is at an extended position. At this point, the floating plate  426  of the rear latch rod  396  has encountered the front edge  438  of the elongate notch  436  of the rack mount member  344 . Any more pull on the front handle  332  at this point will move the front latch rod  394  slightly within the base  390  until the pin  416  of the front floating plate  414  contacts the rear end  444  of the crescent cam groove  412  and the front latch rod  394  will start to move together with the base  390 . However, since the base  390  is axially fixed with respect to the rear floating plate  426  via the slot  446 , and the rear floating plate  426  is contacting the front edge  438  of the elongate notch  436 , the base  390  cannot be pulled any further with respect to the rack mount member  344 . Thus, the rear floating plate  426  and the front edge  438  of the elongate middle notch  436  cooperatively act as a stop feature for the extended position of the module  300 . 
     When the front handle  332  is used to push the center member  340  back to a retracted neutral position, a rearward push on the handle  332  slightly floats the front latch rod  394  with respect to the base  390 . The pin  416  of the floating plate  414  starts to encounter the cam profile of the cam groove  412  and starts moving the floating plate  414  rightward out of the front notch  432  of the rack mount member  344 . The pin  416  of the floating plate  414 , once it contacts a front end  450  of the cam groove  412  stops the floating of the front latch rod  394  with respect to the base  390  of the center member  340  and starts to move the base  390  with the front latch rod  394 . This is, again, due to the front floating plate  414  being within the slot  418  and not being axially movable with respect to the base  390 . 
     At this point, since the entire base  390  is moving and since the rear floating plate  426  is still within the elongate slot  436  and is able to move freely, the rear latch rod  396  also moves with the base member  390 . The rear floating plate  426  slides along the elongate middle notch  436  until the front floating plate  436  reaches the front edge  438  of the middle elongate notch  436  and the rear floating plate  426  encounters the rear edge  440  of the middle notch  436 . The front floating plate  414  is then biased back into the middle notch  436  in a right to left direction. This provides an indication to the user that the module  300  is now in the neutral retracted position. 
     As noted previously, the front and rear latch rods  394 ,  396  cooperate to ensure that the front handle  332  cannot be used to push the module  300  all the way to the rear side of the panel  302  where it can be accessed from the rear side and that the rear handle  334  cannot be used to push the module  300  all the way to the front side of the panel  302  where it can be accessed from the front side. Each of the front and rear handles  332 ,  334  can only be used to move the modules  300  from a neutral position to their respective sides and back to the neutral position. 
     This is accomplished because the floating plates  414 ,  426  are both constrained axially with respect to the base  390  of the center member  340  along a front to back direction by being housed within their respective slots  418 ,  436 . Any movement of the base  390  of the center member  340  moves the floating plates  414 ,  426  axially in the same amount. The floating plates  414 ,  426  can only move axially with respect to the front latch rod  394  or the rear latch rod  396  as the front latch rod  394  and the rear latch rod  396  float within the base  390  of the center member  340 . 
     Thus, when the center member  340  is in the neutral position, any push on the front handle  332  will either move the handle  332  slightly until it contacts the end of the slot  402  defined at the front  404  of the base  390  or move the front latch rod  394  within the base  390  slightly until the pin  416  of the floating plate  414  contacts the front end  450  of the cam groove  412 . When this occurs, the front latch rod  394  will no longer float within the base  390  and the two will have to start moving together. Since the base member  390  does not move axially with respect to the floating plates  414 ,  426  (due to, for example, the rear floating plate  426  being within the slot  436  defined on the base  390 ), any further pushing on the handle  332  of the front latch rod  394  and thus on the center member  340  is prevented the due to the rear floating plate  426  being in contact with the rear edge  440  of the elongate notch  436  of the rack mount member  344 . In this manner, the front handle  332  cannot be used to push the module  300  all the way to the rear side of the panel  302  where it can be accessed from the rear side of the panel  302 . 
     In the depicted embodiment, as described above, the base  390 , the front latch rod  394 , the rear latch rod  396 , and the cover  392  of the center member  340  are arranged such that the rear handle  334  is configured to ride within a slot  406  defined on the cover  392  and the front handle  332  is configured to ride within a slot  402  defined on the base  390  of the center member  340 . 
     The mechanism described above operates in the opposite manner for pulling and pushing the rear handle  334  of the center member  340  for accessing the connection modules  300  from a rear side of the panel  302 . The position of the front and rear floating plates  414 ,  426  within the middle and rear notches  436 ,  438  of the rack mount member  344  are illustrated in  FIGS.  32  and  32 A  when the modules  300  is extended rearwardly. 
     Similar to the embodiment described previously, even though the base  390  and the cover  392  of the center member are depicted as being coupled together with snap-fit interlocks via tabs  452  and recesses  454 , other types of coupling arrangements may be used. For example, threaded fasteners may be used. 
     As in the previous embodiment of the module, at each of the front and rear ends  454 ,  456  of the center member is located a cable management structure  458 . The cable management structure  458  defines a spool  460  and a pair of cable management fingers  462 . Along with the handle  332 ,  334  and the spool  460 , the cable management fingers  462  define a cable path  464  for fiber optic cables coming from or going to the main frame member  342 . For those modules  300  that are located at the left half  330  of the rack mount panel  302 , once cables are lead around the spool  460 , they are guided outwardly away from the left side of the panel  302 . 
     It should be noted that cables from both the front and the back ends  466 ,  468  of the main frame member  342  are guided around a spool  460  located at each of the ends  454 ,  456  of the center member  340  and lead away from the panel  302 . 
     For the modules  300  that are at the left half  330  of the panel  302 , for example, when the center member  340  moves, moving the main frame member  342  therewith, cables coming from the main frame member  342  that are routed around the spools  460  at each end  454 ,  456  of the center member  340  maintain a generally uniform length as they extend to the left side of the panel. 
     As discussed previously, while the front end  466  of the main frame member  342  moves toward the front side of the panel  302 , the front end  454  of the center member  340  and thus the spool  460  located at the front end  454  of the center member  340  also moves simultaneously with the main frame member  342 , taking up any slack in the cable. Similarly, at the same time, while the rear end  468  of the main frame member  342  moves toward the front side of the panel  302 , the rear end  456  of the center member  340  and thus the spool  460  located at the rear end  456  of the center member  340  moves simultaneously in the same direction, reducing any pull or tension on the cable routed through the main frame member  342 . 
     The slide assembly  336  functions in the same manner when the main frame member  342  is moved in the rearward direction for accessing connection locations  346  from a rear side of the panel  302  by pulling the handle  334  at the rear end  456  of the center member  340 . 
     Referring back to  FIGS.  26 - 28   , the main frame member  342  is illustrated. Similar to the modules  20  described above and referring again to the modules  300  located at the left half  330  of the panel  302  for reference, the main frame member  342  includes a right wall  470  and a left wall  472 . The right wall  470  defines the longitudinal protrusion  348  allowing the main frame member  342  to be slidably coupled to the divider  326  at the center of the telecommunications panel  302 . The left wall  472  includes a similar longitudinal protrusion  348  for sliding within the center member  340 . As noted above, each of the longitudinal protrusions  348  of the right wall  470  and the left wall  472  may define a dovetail shaped profile for slidable insertion into dovetail shaped longitudinal groove  354  of the center member  340  and longitudinal track  358  defined on the center divider  326  of the telecommunications panel  302  as shown in  FIG.  25   . 
     The longitudinal protrusion  348  on the left wall  472  of the main frame member  342 , as noted above, also defines the second rack  370  for meshing with the gear  374  located within the center member  340 . 
     As discussed previously, by meshing with both the first rack  372  on the rack mount member  344  and the second rack  372  on the main frame member  342  at the same time, the gear  374  located on the center member  340  allows the center member  340  to move at half linear speed simultaneously with the main frame member  342  in the same direction. 
     The main frame member  342  is configured to provide fiber optic connection locations  346  for the connection module  300 . By stacking a plurality of the modules  300  on both halves  328 ,  330  of the rack mount telecommunications panel  302 , density of connections for fiber optic transmission can be increased and the slidability of the modules  300  in either the front direction or the back direction provides for easy access at both the front side or the rear side of the panel  302 . 
     As shown in  FIGS.  26 - 28   , the depicted version of the main frame member  342  includes a mount  474  for mounting fiber optic adapters  476  which define the fiber optic connection locations  346  in this embodiment of the module  300 . In the depicted embodiment, the mount  474  is defined by a first interlock structure  478  on the right wall  470  that defines dove-tail shaped protrusions and a second interlock structure  480  on the left wall  472  that defines dove-tail shaped grooves. The first and second interlock structures  478 ,  480  are configured for receive fiber optic adapter blocks  482 ,  484  having complementary shapes to the first and second interlock structures  478 ,  480 . For example, a first fiber optic adapter block  482  shown in  FIG.  28    includes dove-tail shaped protrusions  486  on a left wall  488  thereof for slidable insertion into the second interlock structure  480  and dove-tail shaped grooves  490  on the right wall  492  thereof for slidably coupling to a second adapter block  484  with similar interlocking features. The second adapter block  484  defines dove-tail shaped protrusions  494  on the left wall  496  thereof, where it can be mated with the first adapter block  482  and dove-tail shaped grooves  498  on the right wall  500  thereof that can mate with the first interlock structure  478  of the main frame member  342 . In this manner, two adapter blocks  482 ,  484  can be aligned and slidably interlocked and engaged with the main frame member  342 . In the example module  300  shown and described in the present application, the fiber optic connection locations  346  are defined by the first adapter block  482  having adapters  476  with an LC type footprint. The second adapter block  484  that is slidably mated with the first adapter block  482  defines adapters  476  having an SC type footprint. 
     The slidable mounting of the adapter blocks  482 ,  484  provides the advantage of being able to replace the entire connection module  300  without disturbing the connections that are being routed through the connection locations  346  of the main frame member  342 . The adapter blocks  482 ,  484  can simply be slid out and provide clearance for replacing the module  300 . 
     In the depicted embodiments, twelve LC adapters  476  are provided on each block  482 . The main frame member  342  is configured such that another block  482  of twelve LC adapters  476  can be mounted side by side with the first block  482  such that twenty-four connections can be provided on each module  300 . With the panel  302  populated with twelve modules  300  at the left half  330  and twelve modules  300  at the right half  328 , the telecommunications panel  302  can include up to 576 fiber optic connections if LC type adapters  476  are used. 
     In the embodiment shown, if an SC type footprint is used, each module  300  can accommodate up to twelve connections. 
     It should be noted that the connection modules  300  can be used with a single standard or mixed standards of adapters  476  and connectors as shown in  FIG.  28   . Fiber optic adapters  476  are only one type of fiber optic equipment that provides connection locations  346  for the module  300  and the module  300  can be used with other types of fiber optic equipment. For example, equipment such as fiber optic splitters, couplers, multiplexers/demultiplexers, or other types of equipment wherein cables may be routed away from the connection locations  346  may be housed on the main frame member  342 . 
     If fiber optic adapters  476  are used, the connection locations  346  may be defined by adapters  476  individually mounted in the mount  474  or may be defined by blocks that include integrally formed adapters  476  such as those shown in  FIG.  28   . In other embodiments, the connection locations  346  may be in the form of a cassette that includes fiber optic adapters on one side wherein the opposite side either has a multi-fiber connector or a cable extending outwardly therefrom, as described in further detail in U.S. Pat. No. 9,535,229, which has been incorporated herein by reference in its entirety. 
     As long as plurality of fiber optic cables or even a single fiber optic cable is being routed from the main frame member  342 , around the radius limiters  460  of the center member  340 , the slide assembly  336  of the module  300  provides access to those fiber optic terminations while managing the cable slack to prevent pinching and preventing pulling or stressing of the cables. 
     Similar to the embodiment of the module  20  discussed previously, a first cable management structure  502  is defined adjacent the left wall  472  at the front  466  of the main frame member  342 . A second cable management structure  504  is also defined adjacent the left wall  472  at the rear  468  of the main frame member  342 . Each of the first and second cable management structures  502 ,  504  includes a radius limiter  506  and a cable management finger  508  that defines cable paths  510  for guiding cables from connection locations  346  toward ends  454 ,  456  of the center member  340 . 
     Referring now to  FIGS.  25 ,  28 , and  33 - 36   , the panel  302  defines a pair of doors  512  (one at the front side of the panel  302  and one at the rear side of the panel  302 ) for each of the modules  300  mounted on the panel  302 . Each door  512  is pivotally coupled to a hinge structure  514  located generally at the center of the panel  302 , defined by each of the front and rear ends of the center divider  326 . A first hinge  514   a  structure is located at the front of the panel  302  for the front doors  512   a  and a second hinge structure  514   b  is located at the rear of the panel  302  for the rear doors  512   b.    
     Each door  512  is spring loaded and biased to be in a closed position. As will be discussed in further detail below, the doors  512  are temporarily locked in the closed position by the main frame members  342  of the modules  300  and are allowed to be opened by the movement of the main frame members  342  from a neutral position to an extended position. 
     As shown in  FIGS.  33 - 36   , each of the cable management structures  502 ,  504  of the main frame member  342  defines a lock tab  516  that is configured to snap fit within a lock groove  518  of the door  512 . Referring to a module  300  that is at the left half  330  of the panel  302  for reference, when the main frame member  342  is at the retracted neutral position, the lock tab  516  is within the lock groove  518 , keeping the door  512  in a closed position (please see  FIG.  33   ). Once the main frame member  342  is started to initially move toward the extended position, a cam surface  520  defined by a wall  522  of the radius limiter  506  that is on the opposite side from the cable path  510 , starts to abut the a wall  524  defined adjacent the lock groove  518  of the door  512  and starts pivoting the door  512  outwardly from the panel  302  (please see  FIG.  34   ). Once the cam surface  520  has advanced the door  512  far enough to clear the lock tab  516  out of the lock groove  518  of the door  512 , the right wall  470  of the main frame member  342  starts to contact the door  512  and completely pivot it to an open position (please see  FIG.  35   ). The door  512  is shown in an initially closed position in  FIG.  33   . In  FIG.  34   , the main frame member  342  is starting to slide and the cam surface  520  of the radius limiter  506  is starting to advance the door  512  so as to move the lock tab  516  out of the lock groove  518  of the door  512 . In  FIG.  35   , the door  512  is seen as being contacted by the right wall  470  of the main frame member  342  to pivot it to a fully open position. In  FIG.  36   , the door  512  is shown in a fully open position. 
     When the main frame member  342  is moved to the neutral retracted position, the spring biasing the door  512  to the closed position pivots the door  512  to the closed position. When the door  512  is fully closed, the lock tab  516  ends up within the lock groove  518  of the door  512 , not allowing the door  512  to be opened until the main frame member  342  of the module  300  is slidably pulled forwardly. 
     Referring now to  FIG.  37   , a main frame member  600  of another embodiment of a connection module having features that are examples of inventive aspect in accordance with the principles of the present disclosure is illustrated. Except for the differences which will be highlighted hereafter, the main frame member  600  includes features similar to and operates in a similar manner to the main frame member  342  described above and shown in  FIGS.  25 - 36   . The main frame member  600  is configured to be part of a connection module that can be mounted on a rack mount telecommunications panel such as panel  302  described above and shown in  FIG.  25   . The main frame member  600  is configured to be coupled to the rack mount telecommunications panel through a three-piece slide assembly that also includes a rack mount member and a center member, wherein the main frame member  600  is configured to move at twice the speed of the center member with respect to the rack mount member due to a rack and pinion arrangement. 
     Still referring to  FIG.  37   , the main frame member  600  defines a front wall  602  and a rear wall  604 . The front and rear walls  602 ,  604  extend between a right wall  606  and a left wall  608 . A center divider  610  also extends from the front wall  602  to the rear wall  604 . As in main frame member  342  described above, the right wall  606  of the main frame member  600  defines a longitudinal protrusion  612  allowing the main frame member  600  to be slidably coupled to the telecommunications panel  302 . The left wall  608  includes a similar longitudinal protrusion  612  for sliding within the center member of the connection module. As in the previous embodiments, each of the longitudinal protrusions  612  of the right wall  606  and the left wall  608  may define a dovetail shaped profile for slidable insertion into dovetail shaped longitudinal groove of the center member and longitudinal track defined on the telecommunications panel. 
     The longitudinal protrusion  612  on the left wall  608  of the main frame member  600 , as noted for previous embodiments, also defines a rack  614  for meshing with the gear located within the center member (see  FIG.  39   ). 
     As discussed previously, by meshing with both a first rack on the rack mount member and a second rack  614  on the main frame member at the same time, the gear assembly located on the center member allows the center member of the module to move at half linear speed simultaneously with the main frame member  600  in the same direction. 
     The main frame member  600  is configured to provide fiber optic connection locations  616  for the connection module. As discussed above, by stacking a plurality of the modules on both halves of the rack mount telecommunications panel, density of connections for fiber optic transmission can be increased and the slidability of the modules in either the front direction or the back direction provides for easy access at both the front side and the rear side of the panel. 
     Similar to the embodiment of the modules discussed previously, a first cable management structure  618  is defined adjacent the left wall  608  at the front of the main frame member  600 . A second cable management structure  620  is also defined adjacent the left wall  600  at the rear of the main frame member  600 . Each of the first and second cable management structures  618 ,  620  includes a radius limiter  622  and a cable management finger  624  that defines a cable path  626  for guiding cables from connection locations  616  toward ends of the center member of the module. 
     As shown in  FIG.  37   , the depicted version of the main frame member  600  includes a first interlock structure  628  on the left wall  608 , a second interlock structure  630  on the center divider  610 , and a third interlock structure  632  on the right wall  606  of the main frame member  600  for mounting equipment for providing fiber optic connection locations  616  for the module. The first interlock structure  628  defines a groove  634  and a flexible tab  636 . The flexible tab  636  defines a ramped finger  637 , a portion of which extends at least partially into the groove  634 . The third interlock structure  632  on the right wall  606  of the main frame member  600  includes the same configuration as the first interlock structure  628 . The second interlock structure  630  on the center divider  610  is configured for cooperating with both the first interlock structure  628  of the left wall  608  and the third interlock structure  632  of the right wall  606  in receiving telecommunications equipment that provides connection locations  616 . As such, the second interlock structure  630  defines a groove  638  having twice the width as the grooves  634  of the first and the third interlock structures  628 ,  632 . 
     As will be described in further detail below and as noted previously, the first, second, and third interlock structures  628 ,  630 ,  632  are configured to receive equipment such as fiber optic adapter blocks  640  having mounting structures with complementary shapes to those of the first, second, and third interlock structures  628 ,  630 ,  632 . For example, a fiber optic adapter block  640  that may be mounted on the main frame member  600  is shown in  FIGS.  72  and  73   . In the depicted embodiment of the main frame member  600 , two such fiber optic adapter blocks  640  may be mounted in a side by side configuration, wherein one adapter block  640  extends between the left wall  608  and the center divider  610  and the second block  640  extends between the center divider  610  and the right wall  606 . 
     Referring now to the example fiber optic adapter block  640  shown in  FIGS.  72  and  73   , on each of the right and left sides  642 ,  644  of the adapter block  640  is provided a dovetail shaped mounting structure  646 . Each of the dovetail mounting structures  646  is configured to be slidably inserted into the grooves  634 ,  638  defined by the first, second, and third interlock structures  628 ,  630 ,  632  of the main frame member  600 . Since the second interlock structure  630  of the main frame member  600  defines a groove  638  having twice the width of the grooves  634  of the first and third interlock structures  628 ,  632 , dovetail mountain structures  646  of two adapter blocks  640  can fit in a side by side arrangement into the groove  638  of the second interlock structure  630 . The flexible tabs  636  of the first and third interlock structures  628 ,  632  are configured to elastically flex and snap back into position when receiving the dovetail mounting structures  646  of the adapter blocks  640 , with the ramped finger  637  retaining the adapter blocks  640  when received therein. 
     As noted previously, the slidable mounting of the adapter blocks  640  provides the advantage of being able to replace either the blocks  640  themselves or the entire connection module without disturbing the connections that are being routed through the connection locations  616  of the main frame member  600 . If the entire module needs to be replaced, the adapter blocks  640  can simply be slid out and provide clearance for replacing the module. 
     In the depicted embodiments, twelve LC type adapters  650  are provided on each block  640 . The depicted main frame member  600  is configured such that two blocks  640  having twelve LC adapters  650  each can be mounted side by side providing a total of that twenty-four connections on each module. With a telecommunications panel such as the panel  302  shown in  FIG.  25    populated with twelve modules at the left half and twelve modules at the right half, up to 576 fiber optic connections can be provided if LC type adapters  650  are used. 
     In the embodiment shown, if an SC type footprint is used, each main frame member  600  can accommodate up to twelve connections. 
     The adapter block  640  illustrated in  FIGS.  72  and  73    defines a generally one-piece molded body  652  that defines a plurality of integrally formed adapters  650  (LC format in the depicted example) for optically connecting fiber optic cables terminated with connectors. Each of the adapter blocks  640  defines a plurality of adapters  650  provided in a stacked arrangement in a longitudinal direction D, such as from a right side to a left side of the adapter block  640 , wherein every other adapter  650  of the block of adapters is staggered in a transverse direction T, such as in a front to back direction with respect to an adjacent adapter  650  for facilitating finger access. The adapter blocks  640  shown in  FIGS.  72  and  73    are similar in configuration to adapter blocks described and shown in U.S. Pat. No. 9,075,203, the entire disclosure of which is incorporated herein by reference. Thus, further details of the adapter blocks  640  will not be described herein. 
     As noted previously, fiber optic adapters  650  are only one type of fiber optic equipment that may provide connection locations  616  for the module and the module can be used with other types of fiber optic equipment. For example, equipment such as fiber optic splitters, couplers, multiplexers/demultiplexers, or other types of equipment wherein cables may be routed away from the connection locations may be housed on the main frame member  600 . 
     In yet other embodiments, the connection locations  616  may be provided by telecommunications equipment in the form of a cassette that includes fiber optic adapters  650  on one side wherein the opposite side either has a multi-fiber connector or a cable extending outwardly therefrom, as described in further detail in U.S. Pat. No. 9,535,229, which has been incorporated herein by reference in its entirety. 
     In  FIGS.  38 - 49   , an example of a fiber optic cassette  660  that has a pair of the fiber optic adapter blocks  640  mounted on one side and a pair of multi-fiber connectors  662  extending from the opposite side is shown as being mounted on the main frame member  600 . In  FIGS.  50 - 71   , another example of a fiber optic cassette  760  that has a pair of the fiber optic adapter blocks  640  mounted on one side and a pair of cables  762  extending outwardly from the opposite side is shown as being mounted on the main frame member  600 . 
     Now referring back to  FIGS.  72  and  73   , each adapter block  640  defines a ramped tab  654  adjacent the dovetail mounting structure  646  on each of the right and left sides  642 ,  644  of the adapter block  640 . As will be discussed in further detail below, the ramped tabs  654  allow the adapter blocks  640  to be snap-fit and become part of telecommunications equipment such as the fiber optic cassette  660  of  FIGS.  38 - 49    or the fiber optic cassette  760  of  FIGS.  50 - 71   . The ramped tabs  654  are positioned and configured such that they allow the adapter blocks  640  to be mounted directly to the main frame member  600  if desired via the dovetail mounting structures  646 . Or, the tabs  654  allow the adapter blocks  640  to be first snap-fit to the fiber optic cassettes  660 ,  760  and then mounted to the main frame member  600  as part of the fiber optic cassettes  660 ,  760  using the same dovetail mounting structures  646  of the adapter blocks  640 . 
     Now referring to  FIGS.  38 - 49   , the fiber optic cassette  660  is shown in further detail. The fiber optic cassette  660  includes a body  664  defining an open front  666 , a rear wall  668 , a pair of sidewalls  670 ,  672  (i.e., right and left sidewalls), a bottom wall  674 , and a top in the form of a removable cover  676 , all defining an interior  678  of the cassette  660 . 
     Cassette body  664  defines a cable entry location  680  which in the illustrated embodiment is along the rear wall  668 . A pair of MPO style connectors  662  coming from an exterior of the cassette  660  are coupled to a pair of MPO style connectors  662  through a pair of adapters  682  at the cable entry location  680 . The adapters  682  are provided in a staggered arrangement along the longitudinal direction D for facilitating finger access. 
     As shown, each of the connectorized cables  684  extending outwardly from the cassette  660  includes a boot  686  to provide strain relief at cable entry location  680 . 
     As shown, two of the adapter blocks  640  are configured to be snap-fit to the cassette  660  in a side by side configuration at the open front  666  thereof, closing the front  666  of the cassette  660 . The bottom wall  674  of the cassette body  664  defines a front end  688  that matches the staggered configuration of the adapters  650  of the adapter block  640 . 
     Once coupled, the adapters  650  of the blocks  640  are stacked along the longitudinal axis D. The cables  684  at cable entry location  680  extend parallel to the longitudinal axis D, although some bending is permitted relative to the longitudinal axis D. 
     In general, the top defined by the cover  676  and the bottom wall  674  of the cassette  660  are generally parallel to each other and define the major surfaces of cassette body  664 . Sidewalls  670 ,  672 , front  666 , and rear wall  668  define the minor sides of cassette body  664 . The cassette  660  can be oriented in any position, so that the top and bottom surfaces can be reversed, or positioned vertically, or at some other orientation. 
     In the interior  678 , LC connectorized cables that are broken out from each internal MPO connector  662  are led toward the front  666  of the cassette  660  and coupled to the rears  692  of the LC adapters  650  of each adapter block  640 , wherein they can mate with LC connectors  651  coupled at the fronts  694  of the LC adapters  650 . 
     As shown in  FIGS.  40 ,  44 , and  46   , the front end  677  of the cover  676  of the cassette  660  is notched to accommodate the latches  653  of the inner LC connectors  651 . The notches  679  of the cover  676  also provide a visual indication to the exterior of the cassette  660  which adapters  650  have been populated. Since a number of LC connector manufacturers provide their connectors in different colors to indicate different properties of the connections, being able to visually see the different types of LC connectors  651  through the cover  676  may also assist a technician in determining to which telecommunications manufacturers/providers the populated connections belong and the types of the populated connections. 
     Referring now, for example, to  FIG.  109   , the main frame member  600 , the notched front end  677  of the cover  676  of the cassette, and the telecommunications panel  302  to which the main frame member  600  is slidably mounted are configured such that when the module is pulled all the way out of the panel  302  (with the door  512  pivoted all the way out), the cassette  660  extends out of the panel  302  just enough to be able to see the different colors of the latches of the inner LC connectors  651  from an exterior. In this manner, when a technician pulls out one of the modules, the positioning of the cassette  660  on the main frame member and the positioning of the notched front end  677  of the cover  676  on the cassette are such that visual identification of the colors is possible without having to remove the module from the panel  302 . The positioning of the notches of the front end  677  of the cover  676  of the cassette  660  relative to the panel  302  is shown in  FIG.  109    from a top perspective view to illustrate this advantage. 
     This feature may be used on all of the embodiments of the modules/cassettes noted in the present application. Main frame member  600  and the panel  302  are used as an exemplary embodiment to describe and illustrate this feature and should not be used to limit the scope of the disclosure. 
     Disposed within interior  678  of cassette body  664  are a plurality of radius limiters  696  which provide cable bend radius protection for the fibers disposed within interior. Cable radius limiters  696  can be in the form of discrete interior structures, and/or curved exterior surfaces which form around the front, rear wall, and side walls. 
     Removable cable retention fingers  698  may also be provided for retaining cables within the interior  678  of the cassette  660 . Each cable retention finger  698  defines an L-shaped configuration, wherein a mounting portion  697  is removably received within a pocket  700  defined around various parts of the cassette  660  and a retaining portion  699  extends toward the interior  678  of the cassette body  664 . 
     Fibers may be provided with excess length between the interior MPO connectors  662  and the inner LC connectors  651  coupled to the rears  692  of the adapters  650 . Severe bending of the fibers is to be avoided. In the illustrated embodiment, the small size of the cassette  660  may require that some fibers reverse direction. 
     As noted above, the adapter blocks  640  are configured such that they can be snap-fit to the cassette body  664  and also be mounted to the main frame member  600  as part of the cassette  660 . The ramped tabs  654  adjacent the dovetail mounting structures  646  snap into openings  702  provided on the right and left sidewalls  670 ,  672  and at a center divider wall  671  at the front  666  of cassette body  664 . The right and left sidewalls  670 ,  672  of the cassette body  664  are elastically flexible in receiving the ramped tabs  654 . On each side of each adapter block  640 , a protrusion  704  that is above the ramped tab  654  also provides a guiding effect in sliding the ramped tab  654  into the openings  702  and sits on top of a front portion of the cassette  660  after the adapter block  640  has been snap-fit thereto, as shown in  FIG.  41   . 
     Once the adapter blocks  640  have been snap-fit to the cassette  660 , the dovetail mounting structures  646  are used to slide the adapter blocks  640  and thus the cassette  660  into the first, second, and third interlocking structures  628 ,  630 ,  632  of the main frame member  600  as noted above. 
     The fiber optic cassette  660  also includes certain structures that are used to key and couple the cassette  660  to the main frame member  600  in addition to the mounting structures  646  provided by the adapter blocks  640 . For example, as shown in  FIGS.  43 ,  45 ,  47 , and  49   , the cassette  660  defines a pair of protrusions  706  extending from the bottom wall  674  thereof adjacent the rear of the cassette  660  that are configured to snap into openings  708  in the front wall  602  and the rear wall  604  of the main frame member  600  (shown in  FIG.  37   ). Depending upon which orientation the cassette  660  is being used, either the openings  708  on the front wall  602  or the openings  708  on the rear wall  604  of the main frame member  600  are utilized. In the depicted embodiment of  FIGS.  38 - 49   , the rear wall  604  of the main frame member  600  is used for mounting the cassette  660 . It should also be noted that each of the front wall  602  and the rear wall  604  defines a gentle curvature that is matched by a bottom portion  710  of the cassette  660  surrounding the pair of protrusions  706 , as shown in  FIGS.  45 ,  47 , and  49   . The bottom wall  674  of the cassette  660  also defines a notch  712  extending in a front to back direction for accommodating the center divider  610  of the main frame member  600  when the cassette  660  is mounted thereto. 
     A similar snap-fit structure in the form of protrusions  706  extending from the bottom wall  674  of the cassette body  664  and also the notch  712  for accommodating the center divider  610  of the main frame member  600  are also provided in the embodiment of the cassette  760  shown in  FIGS.  50 - 71   . 
     Now referring to embodiment of the fiber optic cassette  760  of  FIGS.  50 - 71   , the fiber optic cassette  760  is another piece of telecommunications equipment that may be mounted to the main frame member  600  of  FIG.  37    for providing connection locations  616  for the module. 
     The fiber optic cassette  760  of  FIGS.  50 - 71   , as depicted, includes many of the features of the cassette  660  of  FIGS.  38 - 49   , such as the adapter block snap-fit features, cable management and retention features, features for mounting the cassette  760  to the main frame member  600  and also cover features that accommodate the LC connector latches. 
     For example,  FIGS.  64  and  66    are close-up views illustrating a right ramped tab  654  of an adapter block  640  snap-fit into an opening  764  on the center divider wall  766  of the fiber optic cassette body  768 .  FIGS.  65  and  67    illustrates a left ramped tab  654  of the adapter block  640  snap-fit into an opening  764  on the left side wall  770  of the fiber optic cassette body  768 .  FIG.  69    is a close-up cross-sectional view illustrating the left ramped tab  654  of the left adapter block  640  snap-fit into an opening  764  on the left side wall  770  of the fiber optic cassette body  768 .  FIG.  70    is a close-up cross-sectional view illustrating the right ramped tab  654  of the right adapter block  640  and the left ramped tab  654  of the left adapter block  640  snap-fit into the opening  764  on the center divider wall  766  of the fiber optic cassette body  768 .  FIG.  71    is a close-up cross-sectional view illustrating the right ramped tab  654  of the right adapter block  640  snap-fit into an opening  764  on the right side wall  772  of the fiber optic cassette body  768 . 
     In the version of the fiber optic cassette  760  of  FIGS.  50 - 71   , the fiber optic signals are input or output from the cassette  760  via direct fiber optic cables  762 , rather than through connectorized cables. Cables  762  entering the cassette  760  are connected to the cable entry location  780  with a crimp tube  782  and a crimp ring  784  which crimps jacket and strength member to crimp tube  782 . A small pocket  786  captures the crimp tubes  782  in a stacked arrangement for retention with cassette body  768 . Pocket  786  captures hex end  788  of crimp tube  782  to retain cables  762  with cassette body  768 . As shown, the pocket  786  is provided in an inset portion  790  defined at the center of the right and left portions of the rear wall  792  of the cassette  760 . The portions of the rear wall  792  surrounding the pocket  786  provide gradual curves  794  as the portions extend from the pocket  786  to portions of the rear wall  792  that are parallel to the longitudinal axis D. Thus, when the cable  762  placed in the pocket  786  is bent in either direction toward the right side or the left side of the cassette  760 , bend radius protection is provided with the curved portions  794  of the rear wall  792 . This provides a built-in bend radius protection structure that may eliminate the need for a separate boot for each of the cables  762 . 
     The interior  796  of the cassette body  768  generally defines two separately identifiable chambers  798 ,  800 , each one including a radius limiter  801  (e.g., in the form of a spool) with cable retention fingers  802  extending therefrom. As shown in  FIGS.  56 - 59   , the optical fibers  804  that are input into the cassette  760  through the bottom connectorized cable  762  are led to the right chamber  798  and the optical fibers  804  input into the cassette  760  through the top connectorized cable  762  are led to the left chamber  800  before being led to the adapter blocks  640 . 
     As discussed previously, parts of the telecommunications equipment described herein such as the high density distribution frame  10  or the telecommunications panel  302  may be configured to relay physical layer information from one or more fiber optic connectors (e.g., connectors  135 ,  651 ) received into the connection locations of the main frame members (such as main frame member  26  of  FIGS.  8 - 9   , main frame member  342  of  FIGS.  26 - 28   , or main frame member  600  of  FIG.  37   ) to other parts of the distribution frame  10  or telecommunications panel  302 . 
     As described previously, certain types of adapters that may form the connection locations may be configured to collect physical layer information from one or more fiber optic connectors received thereat. For example, structures such as the fiber optic adapter blocks  482 ,  484 , or  600  may include bodies configured to hold one or more media reading interfaces that are configured to engage memory contacts on fiber optic connectors inserted into the individual adapters of the blocks. One or more media reading interfaces may be positioned in each adapter body within the blocks. Certain types of media reading interfaces may include one or more contact members that are positioned to engage memory contacts on a fiber optic connector inserted within a slot of the adapter. Another portion of each such contact member may also extend out of the adapter slot to contact a circuit board that may be positioned on the block body. Please refer to  FIG.  23    for an example illustration of an adapter configured to collect physical layer information from one or more fiber optic connector received thereat. As will be described in further detail below, portions of the main frame members, the center members, or the rack mount members may define conductive paths that are configured to connect the media reading interfaces of the adapters with a master circuit board located elsewhere on the distribution frame  10  or the panel  302 . The master circuit board may include or connect (e.g., over a network) to a processing unit that is configured to manage physical layer information obtained by the media reading interfaces. 
     Referring now to  FIGS.  29 ,  30 , and  33 - 36   , the main frame member  342 , the center member  340 , and the rack mount member  344  of the telecommunications module  300  have been shown as including structures forming part of a conductive path for relaying physical layer information from a connector mounted to the module to other portions of the telecommunications panel  302 . It should be noted that the structures used on the telecommunications module  300  that form the conductive paths can be used on any of the telecommunications modules discussed herein and that the module  300  is simply one representative example embodiment used to illustrate such features. 
     As shown in  FIGS.  29 ,  30 , and  33 - 36   , the main frame member  342  and the rack mount member  344  may include electrical connector locations  900  ( 900   a ,  900   b ,  900   c ,  900   d ) defined thereon. As shown in  FIG.  29    and  FIGS.  33 - 36   , an electrical cable  902  (e.g., a multi contact electrical cable) may extend from a connection location  900   b  on the main frame member  342  to a connector location  900   c  on the rack mount member  344 . The cable, which has been illustrated diagrammatically in the drawings, according to one example embodiment, may be a flexible, flat ribbon-type, multi-contact electrical cable. As shown in  FIG.  29   , the cable  902  that extends from the connection location  900   b  may be nested within the longitudinal groove  354  defined on the right side  356  of the center member. The cable  902  may extend from the longitudinal groove  354  through a passage defined within the interior of the spool  460  of the center member  340  to the second longitudinal groove  360  on the left side of the center member  340  (that also receives the longitudinal protrusion  364  defined by the rack mount member  344 ). From within the longitudinal groove  360 , the cable  902  extends to connector location  900   c  defined on the rack mount member  344 . 
     As shown in  FIGS.  33 - 36   , due to the three-piece slide assembly, when the main frame member  342  moves forwardly relative to the center member  340  and also the rack mount member  344 , the center member  340  also moves forwardly relative to the rack mount member  344  (at half the speed of the center member  342  relative to the rack mount member  344 ). Stated in an another way, when the main frame member  342  moves forwardly relative to the center member  340 , the rack mount member  344  moves rearwardly relative to the center member  340 . In this manner, the cable  902  used to provide the electrical pathway from connector location  900   b  to connector location  900   c  can always maintain the same length, sliding within the spool  460  as needed. The slidable movement of the cable  902  is shown in  FIGS.  33 - 36   . 
     The main frame member  342  may include internal electrically conductive structures (i.e., integrally formed with or embedded therein) that establish electrically conductive paths from the connector location  900   b  to connector location  900   a  that is provided on the mount  474 . Similarly, the rack mount member  344  may include internal electrically conductive structures that establish an electrical path from the connector location  900   c  to connector location  900   d.    
     The connector location  900   a  is configured such that it can make electrical contact with conductive portions or contact portions (e.g., on a circuit board) of an adapter block such as block  482 ,  484 , or  640  that may be mounted on the mount  474 . As such, physical layer information from a connector mounted to an adapter block of the module may be relayed from the adapter block, through the mount  474 , to the left side of the rack mount member  344  via the cable  902 . 
     Internal electrical conductive paths from the connector location  900   c  to connector location  900   d  relay the physical layer information that is transmitted via the cable  902 . At connector location  900   d , the electrical signals all the way from inserted fiber optic connectors may be relayed to a master circuit board located elsewhere on the panel  302  (e.g., at right wall  310  or at left wall  314 ). As noted above, the master circuit board may include or connect (e.g., over a network) to a processing unit that is configured to manage physical layer information obtained by the media reading interfaces. 
     Even though in one embodiment, the electrically conductive paths between connector locations  900   a  and  900   b  and connector locations  900   c  and  900   d  have been described as being provided by internal conductive structures that may be integrally formed with or embedded into the portions of the main frame member  342  or the rack mount member  344 , in other embodiments, the main frame member  342  and the rack mount member  344  can be configured such that the electrically conductive paths are provided by flexible cabling such as the cable  902 . In such embodiments, the cabling extending between connector locations  900   a  and  900   b  and connector locations  900   c  and  900   d  may be extensions of cable  902 . 
     It should be noted that although an example electrical conductive path has been discussed with respect to the front side of the module  300 , a similar path including a cable  902  and connector locations  900  can be provided at the rear side of the module. 
     Now referring to  FIGS.  74 - 89   , another embodiment of a fiber optic cassette  1000  is illustrated. The fiber optic cassette  1000  is another piece of telecommunications equipment that may be mounted to the main frame member  600  of  FIG.  37    for providing connection locations  616  for the module. 
     The fiber optic cassette  1000  of  FIGS.  74 - 89   , as depicted, shares many of the features of the cassette  660  of  FIGS.  38 - 49    and cassette  760  of  FIGS.  50 - 71   , such as the adapter block snap-fit features, cable management and retention features, features for mounting the cassette  1000  to the main frame member  600  and also cover features that accommodate the LC connector latches. In the depicted embodiment of the cassette  1000 , the fiber optic signal entry and exit points are defined by the snap-in adapter blocks  640  at the front  1001  of the cassette body  1002  rather than a cable entry point at the rear  1003  of the cassette body  1002  as in the cassette  660  of  FIGS.  38 - 49    and the cassette  760  of  FIGS.  50 - 71   . 
     In addition to the shared features, the fiber optic cassette  1000  of  FIGS.  74 - 89    also includes additional features that will be described in further detail below. For example, as shown in the exploded view of  FIG.  78   , the interior  1004  of the cassette body  1002  generally defines two separately identifiable chambers  1006 , each one including a cable management structure in the form of a plurality of discrete posts  1008 . The posts  1008  may be structures that are integrally molded with the body  1002  of the fiber optic cassette  1000 . In other embodiments, the posts  1008  may be removable structures. The plurality of discrete posts  1008  are configured and positioned to resemble the shape of a circular spool structure such that an outer perimeter defined by the posts  1008  still meets the minimum bend radius requirements for any cables that are routed around the posts  1008 . In addition to providing bend radius protection around the outer periphery of the posts  1008 , the discrete, spaced-out configuration of the posts  1008  also allows any cabling to be routed through the region  1010  defined at the interior of the posts  1008 . Example cable routing configurations are shown in  FIGS.  79 - 89   , wherein cables  1012  can be routed around the posts  1008  or through the region  1010  defined at the interior of the posts  1008 . 
     As shown in  FIG.  78   , the fiber optic cassette  1000  also includes removable cable retention fingers  1014  similar to fingers  698  of fiber optic cassette  660  of  FIGS.  38 - 49    and finger  802  of fiber optic cassette  760  of  FIGS.  50 - 71   . The cable retention fingers  1014  provide additional cable management for cables  1012  routed around and/or through the posts  1008  within the cassette body interior  1004  as shown in  FIGS.  79 - 89   . As shown in  FIGS.  74 - 89   , other integral portions of the cassette body  1002  such as the rear wall  1016  or the side walls  1018  may provide cable management features such as curved surfaces for meeting bend radius requirements. 
     Still referring to  FIG.  78   , the interior  1004  of the cassette body  1002  defines a rear pocket  1020  behind the discrete posts  1008 . As will be described in further detail below, the pocket  1020  may be used to house fiber optic equipment  1022  (i.e., devices) within the cassette  1000 , wherein fiber optic signals may be routed between the fiber optic equipment  1022  and the fiber optic adapters  650  of the adapter blocks  640  at the front  1001  of the cassette  1000  ( FIGS.  82 - 89   ). As also shown in  FIGS.  79 - 81    and will be described in further detail, the fiber optic signals may be routed from one connection point on the fiber optic equipment  1022 , through the cassette body  1002 , to another connection point on the equipment  1022 . 
     One example embodiment of a piece of fiber optic equipment  1022  that may be used within the cassette  1000  are a plurality of thin film filters  1024 , as shown in the depicted embodiment of the cassette  1000  in  FIGS.  78 - 89   . In other embodiments, other types of fiber optic equipment  1022  including fuse biconic couplers (such as fiber optic splitters, couplers, or equipment having monitoring circuitry), equipment having planar lightwave circuitry (PLC) such as splitters, or equipment such as multiplexers/demultiplexers can be used within the cassette  1000 . 
     Depending upon the type of equipment  1022  used, the inputs and the outputs for the fiber optic signals can be arranged differently. For example, depending upon the type of equipment  1022  used, the inputs and outputs may be located on opposite sides of the device  1022  (e.g., right side  1026  and left side  1028 ). For example, according to one example embodiment, the inputs for the device  1022  may be located at the right side  1026  of the device  1022  and the outputs may be located at the left side  1028  of the device  1022 . The locations of the inputs and the outputs can be interchanged, wherein the inputs may be located at the left side  1028  of the device  1022  and the outputs located at the right side  1026  of the device  1022 . 
     If a plurality of smaller devices  1022  are used in a stacked arrangement such as the thin film filters  1024  shown in  FIGS.  78 - 89   , the inputs and the outputs may be provided in an alternating arrangement between the right side  1026  and the left side  1028  from one filter  1024  to the next. 
     Also, in certain embodiments, as will be described in further detail below, the signals may simply extend from the fiber optic device  1022  to connectors within the fiber optic adapters  650  at the front  1001  of the cassette  1000  without being routed back to the device  1022 . 
       FIGS.  79 - 89    depict eleven different example cable routing configurations that may be used within the fiber optic cassette  1000 . The eleven example cable routing configurations are provided to illustrate the vast number of cable routing possibilities that may be used given the features of the fiber optic cassette  1000  and are not intended to limit the scope of the disclosure in any way. Other cable routing configurations are certainly possible and are contemplated by the present disclosure. Also, in the routing configurations shown in  FIGS.  79 - 89   , only one or two representative cables  1012  have been used to demonstrate the routing possibilities, without populating all of the equipment connection locations. 
       FIG.  79    illustrates a first example cable routing configuration within the cassette  1000  wherein a signal carrying cable  1012  is routed between a connection location  1027  at the right side  1026  of the device  1022  and a connection location at the left side  1028  of the device  1022  after extending around the cable management posts  1008 . 
       FIG.  80    illustrates a second example cable routing configuration within the cassette  1000  wherein a signal carrying cable  1012  is routed from a connection location  1027  at the right side  1026  of the device  1022  to another connection location  1027  at the same, right, side  1026  of the device  1022  after extending around the cable management posts  1008 . 
       FIG.  81    illustrates a third example cable routing configuration within the cassette  1000  wherein a signal carrying cable  1012  is routed from a connection location  1027  at the left side  1028  of the device  1022  to another connection location  1027  at the same, left, side  1028  of the device  1022  after extending around the cable management posts  1008 . This configuration is similar to that of  FIG.  80   , except for the change in the orientation of the side. 
       FIG.  82    illustrates a fourth example cable routing configuration within the cassette  1000  wherein signal carrying cables  1012  are routed from a connection location  1027  at the right side  1026  of the device  1022  to fiber optic adapters  650  located generally to the left of the device  1022  at the front  1001  of the cassette  1000 . 
       FIG.  83    illustrates another example cable routing configuration within the cassette  1000  similar to the configuration of  FIG.  82   , wherein signal carrying cables  1012  are routed from a connection location  1027  at the right side  1026  of the device  1022  to fiber optic adapters  650  located generally to the left of the device  1022  at the front  1001  of the cassette  1000 . 
       FIG.  84    illustrates a sixth example cable routing configuration within the cassette  1000  wherein signal carrying cables  1012  are routed from a connection location  1027  at the left side  1028  of the device  1022  to fiber optic adapters  650  located generally to the right of the device  1022  at the front  1001  of the cassette  1000 . This configuration is similar to that of  FIG.  82   , except for the change in the orientation of the side. 
       FIG.  85    illustrates another example cable routing configuration within the cassette  1000  similar to the configuration of  FIG.  84   , wherein signal carrying cables  1012  are routed from a connection location  1027  at the left side  1028  of the device to fiber optic adapters  650  located generally to the right of the device  1022  at the front  1001  of the cassette  1000 . This configuration is similar to that of  FIG.  83   , except for the change in the orientation of the side. 
       FIG.  86    illustrates an eighth example cable routing configuration within the cassette  1000  wherein signal carrying cables  1012  are routed from a connection location  1027  at the right side  1026  of the device  1022  to fiber optic adapters  650  located generally to the right of the device  1022  at the front  1001  of the cassette  1000  after being routed around posts  1008  on both sides of the cassette  1000 . 
       FIG.  87    illustrates another example cable routing configuration within the cassette  1000  similar to the configuration of  FIG.  86   , wherein signal carrying cables  1012  are routed from a connection location  1027  at the right side  1026  of the device  1022  to fiber optic adapters  650  located generally to the right of the device  1022  at the front  1001  of the cassette  1000  after being routed around posts  1008  on both sides of the cassette  1000 . 
       FIG.  88    illustrates a tenth example cable routing configuration within the cassette  1000  wherein signal carrying cables  1012  are routed from a connection location  1027  at the left side  1028  of the device  1022  to fiber optic adapters  650  located generally to the left of the device  1022  at the front  1001  of the cassette  1000  after being routed around posts  1008  on both sides of the cassette  1000 . This configuration is similar to that of  FIG.  86   , except for the change in the orientation of the side. 
       FIG.  89    illustrates another example cable routing configuration within the cassette  1000  similar to the configuration of  FIG.  88   , wherein signal carrying cables  1012  are routed from a connection location  1027  at the left side  1028  of the device  1022  to fiber optic adapters  650  located generally to the left of the device  1022  at the front  1001  of the cassette  1000  after being routed around posts  1008  on both sides of the cassette  1000 . This configuration is similar to that of  FIG.  87   , except for the change in the orientation of the side. 
     Now referring to  FIGS.  90 - 99   , another embodiment of a fiber optic cassette  1100  is illustrated. The fiber optic cassette  1100  is another piece of telecommunications equipment that may be mounted to the main frame member  600  of  FIG.  37    for providing connection locations  616  for the module. 
     The fiber optic cassette  1100  of  FIGS.  90 - 99   , as depicted, shares many of the features of the cassette  660  of  FIGS.  38 - 49   , cassette  760  of  FIGS.  50 - 71   , and cassette  1000  of  FIGS.  74 - 89   , such as the adapter block snap-fit features, cable management and retention features, features for mounting the cassette  1100  to the main frame member  600  and also cover features that accommodate the LC connector latches. In the depicted embodiment of the cassette  1100 , the fiber optic signal exit points may be defined by the snap-in adapter blocks  640  at the front  1101  of the cassette body  1102  and cable entry points may be defined at the rear  1103  of the cassette body  1102  by MPO style connectors  662 . In the depicted embodiment of the cassette  1100 , the cable entry points may be defined by a pair of MPO style connectors. A pair of MPO style connectors  662  coming from an exterior of the cassette  1100  are coupled to a pair of MPO style connectors  662  through a pair of adapters  682  that are mounted at the rear  1103  of the cassette  1100 . 
     Referring to  FIGS.  90 - 99   , cassette  1100  defines a rear extension  1120  that is configured to support the pair of adapters  682 . The cassette  1100  includes a cover  1122  that is sized generally smaller than the cassettes of the previous embodiments such that the rear extension  1120  stays exposed to an exterior of the cassette  1100 . 
     The rear extension  1120  is defined by a rear wall  1124 , an intermediate wall  1126  of the cassette  1100  and a bottom  1128  that extends between the rear wall  1124  and the intermediate wall  1126  of the cassette  1100 . The rear extension  1120  also includes a divider  1130  located between the intermediate wall  1126  and the rear wall  1124  defining the rear extension  1120 . 
     The pair of adapters  682  each includes flanges  1132  on opposing sides of the adapter bodies. The flanges  1132  are slidably inserted into notches  1134  defined on each of the rear wall  1124 , the intermediate wall  1126 , and the divider structure  1130  of the rear extension  1120 . As shown in  FIGS.  90  and  91   , the notches  1134  are positioned such that when the adapters  682  are slidably inserted therein, the adapters  682  are positioned in a staggered configuration. The staggering provides cable management and also preserves bend radius requirements. 
     The flanges  1132  of the adapters  682  and the notches  1134  are sized to provide a friction fit for retaining the adapters  682  at the rear extension  1120 . The accessibility and removability of the adapters  682  due to the exposed rear extension  1120  facilitate inspection and/or cleaning of the adapters  682  or the connectors  662  coupled therewith. 
     As noted above, a pair of MPO style connectors  662  are coupled to right ends  1136  of the adapters  682  in the depicted example. Each of the MPO style connectors  662  are terminated with cabling  1138  (i.e., pigtails) that extend between the connectors  662  and a crimp location  1140 . In the depicted embodiment, the connectors  662  include pigtails  1138  that extend from the connectors  662  to a crimp location  1140  at the right side  1142  of the cassette  1100 . It should be noted that, as seen in  FIG.  99   , connectors  662  can be provided at left ends  1144  of the adapters  682 , wherein pigtails  1138  could extend from the connectors  662  to a crimp location  1140  at the left side  1146  of the cassette  1100 . Thus, the cassette  1100  allows the intermediate MPO connectors  662  (e.g., the connectors that relay the signal from external connectors through the adapters  682 ) to be located at either end of the adapters  682 . 
     The crimp locations  1140  at either the right side  1142  or the left side  1146  of the cassette  1100  are defined by small pockets  1150 . The pigtails  1138  entering the cassette  1100  are connected to the crimp locations  1140  with a crimp tube  1152  and a crimp ring  1154  which crimps the jacket and strength member of the cabling  1138  to crimp tube  1152 . The small pockets  1150  defined at each crimp location  1140  capture the crimp tubes  1152  in a side by side stacked arrangement for retention with the cassette body  1102 . Each pocket  1150  defining the crimp location  1140  captures the hex end  1156  of crimp tube  1152  to retain cables  1138  with the cassette body  1102 . Portions  1160  of the intermediate wall  1126  surrounding the pockets  1150  provide gradual curves as the portions  1160  extend from the pockets  1150  to portions of the intermediate wall  1126  that are parallel to the rear wall  1124 . Thus, bend radius protection is provided with the curved portions  1160  of the intermediate wall  1126 . 
     Referring now to  FIGS.  97 - 99   , the interior  1162  of the cassette body  1102  generally defines two separately identifiable chambers  1164 , each chamber  1164  including a radius limiter  1166  (e.g., in the form of a spool) with removable cable retention fingers  1168  extending therefrom, similar to the embodiments of the cassettes described previously. 
     Connectorized cables  1170  (e.g., cables terminated with LC type fiber optic connectors) extending from the crimp locations  1140  may be lead around the radius limiters  1166  before being directed to the fiber optic adapter blocks  640  at the front  1101  of the cassette  1100 , with a variety of different cable routing configurations. 
     Referring now to  FIGS.  100 - 114   , various example cable routing configuration are shown for a telecommunications rack  2000  that is configured to house a plurality of distribution panels  2002  similar to the distribution panel  302  of  FIG.  24   . As will be described in further detail below, the telecommunications rack  2000  includes a variety of cable management features for managing incoming cables and outgoing cables and cabling within the rack  2000  itself. Cross-connect patching can also be provided between multiple similar racks  2000  using the cable management features of the racks  2000 . 
     The cable management features of the telecommunications rack  2000  have been designed such that the same length cables incoming to the rack  2000  from above or below the rack  2000  can be routed to different portions of the rack  2000 , with the slack being stored as needed on the features of the rack  2000 . 
     Referring now to  FIG.  100    specifically, the telecommunications rack  2000  is shown from a rear side  2004  with one of the distribution panels  2002  mounted thereon and with an example cable routing configuration around portions of the rack  2000 . As shown, in the rear side  2004 , the rack  2000  defines vertical cable guides  2006 ,  2008 , respectively, on both the right and left sides  2010 ,  2012  of the rack extending along the height of the rack  2000 . A cross-frame trough  2014  is provided for each panel  2002  and connects the vertical cable guides  2006 ,  2008  on the right and left sides  2010 ,  2012 . A radius limiter  2016  in the form of a trumpet flare is provided on the right end of the cross-frame trough  2014 . A second trumpet flare  2018  is provided below the first trumpet flare  2016  on the right side  2010  of the rack  2000 . At the left side  2012  of the rack  2000 , a radius limiter  2020  (e.g., a spool) is located within the left vertical cable guide  2008 . Although not shown in  FIG.  100   , a radius limiter  2040  (e.g., a spool) may also be mounted at the right side  2010  of the rack  2000  for each panel  2002  (see  FIG.  103   ) within the right vertical cable guide  2006 , in offset relationship with respect to the spool  2020  on the left side  2012 . Still referring to  FIG.  100   , the rack  2000  also includes a rear horizontal trough  2022  extending between the right side  2010  and the left side  2012  of the rack  2000 . Front-to-rear troughs  2024 ,  2026  are also provided at each of the right and left sides  2010 ,  2012 , respectively, of the rack  2000  for routing cables between a front side  2028  and the rear side  2004  of the rack  2000  as will be discussed in further detail below. 
     It should be noted that the terms “right” and “left” are used to refer to the right and left sides of the rack when looking at the rack  2000  from a rear view thereof (i.e. when a person is standing at the rear of the rack). 
     Still referring to  FIG.  100   , an example cable routing configuration for cables extending from modules of the panel  2002  is shown for a rear side  2004  of the rack  2000 . In the example shown in  FIG.  100   , for the module located at the right side  2010  of the rack  2000 , a cable  2030  extending from an adapter  650  mounted on one of the main frame members  600  is lead around the cable management features of a center member  340  of the module and downwardly around fingers  2032  at the right side  2010  of the rack  2000 . From the fingers  2032 , the cable  2030  goes through the second trumpet flare  2018  and up or down the vertical cable guide  2006  at the right side  2010  of the rack  2000 . For a cable  2030  extending from a module at the left side  2012  of the rack  2000 , the cable  2030  is lead around the cable management features of the center member  340  of the module and downwardly around fingers  2034  at the left side  2012  of the rack  2000 . Thereafter, the cable  2030  is lead upwardly around the radius limiter  2020  and into the cross-frame trough  2014 . The cable  2030  then extends through the cross-frame trough  2030  and out the first trumpet flare  2016  and upwardly or downwardly into the vertical cable guide  2008  at the left side  2012  of the rack  2000 . 
       FIG.  101    illustrates an example cable routing configuration for a fiber optic cassette similar to the cassette  760  of  FIGS.  50 - 71    mounted on the panel  2002  of  FIG.  100   , the cable routing shown for a rear side  2004  of the rack  2000 . As discussed above, the slide assembly of the module carrying the cassette  760  provides a mechanism to take up the cable slack from the cassette  760  as the main frame member  600  is being moved back and forth on the panel  2002 . 
       FIG.  102    illustrates an example cable routing configuration for the telecommunications rack  2000  for two incoming cables  2030  (e.g., an IFC cable) routed to the modules located on the rack  2000 . In the illustrated example, the cables  2030  are incoming from a top side  2036  of the rack  2000  and are clamped at the top, right side of the rack  2000 . In the example shown, one of the cables  2030  is routed through the vertical cable guide  2006  at the right side  2010  of the rack  2000 . A drip loop  2039  is formed. If the cable  2030  is being terminated at the right side  2010  of the rack  2000 , the cable  2030  is routed through the second trumpet flare  2018  and into a module at the right side  2010  of the rack  2000 . If the cable  2030  is being terminated at the left side  2012  of the rack  2000 , the cable  2030  is routed through the crossframe trough  2014 , around spool  2020 , and into one of the modules within the panel  2002  at the left side  2012  of the rack  2000 .  FIG.  102 A  is a close up view of the radius limiter  2020  in the form of a spool at the left side  2012  of the rack  2000 .  FIG.  102 B  is a close up view of the second trumpet flare  2018  at the right side  2010  of the rack  2000 . 
       FIG.  103    illustrates an example cable routing configuration for the telecommunications rack  2000  of  FIG.  100    for two incoming cables  2030  routed to the modules located on the rack  2000 , the cables  2030  incoming from a bottom side  2038  of the rack  2000 . Cables  2030  are clamped at bottom, right side of the rack  2000 . The cables  2030  are routed through the vertical cable guide  2006  at the right side  2010  of the rack  2000 . If the cable  2030  is terminated on the right side  2010  of the rack  2000 , the cable  2030  is routed through the second trumpet flare  2018  and to the module. The slack is taken up by an appropriate spool  2040  on the right side  2010  of the rack  2000 . If the cable  2030  is being terminated on the left side  2012  of the rack  2000 , the cable  2030  is routed through the crossframe trough  2014 , around spool  2020  and into a module at the left side  2012  of the rack  2000 . The slack is again taken up by a spool  2040  within the vertical cable guide  2006  on the right side  2010  of the rack  2000 .  FIG.  103 A  is a close up view of the radius limiter  2020  in the form of a spool at the left side  2012  of the rack  2000 .  FIG.  103 B  is a close up view of the second trumpet flare  2018  at the right side  2010  of the rack  2000 . 
       FIG.  104    illustrates an example cable routing configuration for the telecommunications rack  2000  of  FIG.  100    for incoming patch cords  2030  routed to the modules located on the rack  2000 , the patch cords  2030  incoming from the top  2036  of the rack  2000 . The patch cords  2030  are routed downwardly through the right vertical cable guide  2006 . If the cable  2030  is being terminated at the right side  2010  of the rack  2000 , the cable  2030  is routed through the second trumpet flare  2018  to the module. If the cable  2030  is being terminated at the left side  2012  of the rack  2000 , the cable  2030  is routed through the crossframe trough  2014 , around spool  2020  on the left side  2012  of the rack  2000  and into the module.  FIG.  104 A  is a close up view of the radius limiter  2020  in the form of a spool at the left side  2012  of the rack  2000 .  FIG.  104 B  is a close up view of the second trumpet flare  2018  at the right side  2010  of the rack  2000 . 
       FIG.  105    illustrates an example cable routing configuration for the telecommunications rack  2000  of  FIG.  100    for an incoming cable  2030  that leads to a splice region or chassis  2042  of the rack  2000 , the cable  2030  incoming from the top  2036  of the rack  2000 . As shown in  FIG.  105   , the cable  2030  is clamped from overhead at the top, right side of the rack  2000 . The cable  2030  is routed downwardly through the right vertical cable guide  2006  into the splice chassis  2042 . A splice chassis similar to the splice chassis  2042  that may be provided on the rack  2000  of the present disclosure is described in further detail in U.S. Pat. No. 9,348,105, the entire disclosure of which is incorporated herein by reference. 
     The splice chassis  2042 , one example embodiment of which can be used on the rack  2000 , is illustrated in  FIGS.  115 - 118    and will be discussed in further detail below. 
     Referring now to  FIG.  106   , an example cable routing configuration is illustrated for the telecommunications rack  2000  of  FIG.  100    for incoming cables  2030  that lead to the splice chassis  2042  of the rack  2000 , wherein the cables  2030  are incoming from the bottom  2038  of the rack  2000 . In such a routing, the cables  2030 , which are clamped underfloor at the bottom, right side of the rack  2000 , are routed upwardly through the vertical cable guide  2006  at the right side  2010  of the rack  2000  into the splice chassis  2042 . 
       FIG.  107    illustrates an example cable routing configuration within the rack  2000  for a pigtail cables  2030  extending from the modules of the telecommunications rack  2000  of  FIG.  100    to the splice chassis  2042  of the rack  2000 . If the cable  2030  going toward the splice chassis  2042  is coming from a module on the right side  2010  of the rack  2000 , the cable  2030  is routed through second trumpet flare  2018  and downwardly through vertical cable guide  2006  at the right side  2010  of the rack  2000  to the splice chassis  2042 . If the cable  2030  going toward the splice chassis  2042  is coming from a module on the left side  2012  of the rack  2000 , the cable  2030  is routed down and around the radius limiter  2020  and up around the crossframe trough  2014 . After passing through the first trumpet flare  2016 , the cable  2030  is routed downwardly through vertical cable guide  2006  at the right side  2010  of the rack  2000  to the splice chassis  2042 .  FIG.  107 A  is a close up view of the radius limiter  2020  in the form of a spool at the left side  2012  of the rack  2000 .  FIG.  107 B  is a close up view of the second trumpet flare  2018  at the right side  2010  of the rack  2000 . 
       FIGS.  108 - 113    illustrate example cable routing configurations at the front side  2028  of the rack  2000 , wherein patch cord cabling might be utilized. At the front side  2028 , the rack  2000  includes the front-to rear troughs  2024 ,  2026  that communicate with the rear horizontal troughs  2022  at the rear  2004  of the rack  2000 . Cable loops  2044  are provided adjacent both the right and left sides  2010 ,  2012  of the rack  2000 , wherein the cable loops  2044  are located within right and left front vertical cable guides  2046 ,  2048 , respectively. In the depicted embodiment, the rack  2000  also includes cable slack management spools  2050  at the right side  2010  of the rack  2000 , wherein the spools  2050  are in a stacked configuration along a column at the right side  2010  of the rack  2000 , at the front  2028  of the rack  2000 . 
     For example,  FIG.  108    illustrates a front perspective view of the telecommunications rack  2000  of  FIG.  100   , showing an example cable routing configuration at the front side  2028  of the rack  2000 , the cables  2030  extending from the modules mounted on a distribution panel  2002  similar to the distribution panel  302  of  FIG.  24    which is mounted on the rack  2000 . A cable  2030  in the form of a patch cord may be routed from the adapter ports  650  of a cassette similar to the cassette  760  of  FIGS.  50 - 71    to different locations around the rack  2000 . For example, still referring to  FIG.  108   , for the module located at the left side  2012  of the rack  2000 , a cable  2030  extending from an adapter  650  mounted on one of the main frame members  600  is lead around the cable management features of a center member  340  of the module and downwardly around fingers  2052  at the left side  2012  of the rack  2000 . From the fingers  2052 , the cable  2030  can either extend through front-to-rear troughs  2026  to the rear horizontal trough  2022  and then to a destination rack  2000  for patching or down through the vertical cable guide  2048  through the cable loops  2044 . A similar cable routing configuration may be followed for the module located at the right side  2010  of the rack  2000 . 
       FIG.  109    illustrates an example cable routing configuration at the front side  2028  for a fiber optic cassette that may be mounted on a main frame member  600  on the panel  2002 . As discussed above, the slide assembly of the module provides a mechanism to take up the cable slack from the cassette as the main frame member  600  is being moved back and forth on the panel  2002 . 
       FIG.  110    illustrates an example cable routing configuration for cross-connect cabling within the same rack  2000  from one module on a panel  2002  to another module on another panel  2002  within the rack  2000 , wherein the modules are located on opposite sides  2010 ,  2012  of the rack  2000 . A cable  2030  coming from a first termination point on a module is routed down through the vertical cable guide  2046  on the right side  2010  to a bottom trough  2054 . The cable  2030  is terminated to a second termination point on a module after passing around an anchor spool  2056  provided adjacent the bottom trough  2054  at the front, right side of the rack  2000 . The cable  2030  is lead through the bottom trough  2054  and upwardly along the vertical cable guide  2048  at the left side  2012  of the rack  2000  before being terminated to the second termination point. Slack cabling is looped over storage spools  2050  at the right side  2010  of the rack  2000 . 
       FIG.  111    illustrates an example cable routing configuration for cross-connect cabling within the same rack  2000  similar to that shown in  FIG.  110   , however, between modules on the right side  2010  of the rack  2000  and between modules on the left side  2012  of the rack  2000 . A routing similar to that shown in  FIG.  110    is followed, however, crossing the bottom trough  2054  twice, going within the vertical cable guides  2046 ,  2048  twice, and going around the anchor spool  2056  twice for the respective terminations. 
       FIG.  112    illustrates an example cable routing configuration for cross-connect cabling between two of the telecommunications racks  2000  of  FIG.  100   . In the example configurations shown in  FIG.  112   , once the proper patch cord length is determined, a cable  2030  from either a module on the left side  2012  or a module on the right side  2010  is routed through a respective front-to-rear trough  2024 ,  2026  to the rear horizontal trough  2022  to the destination rack  2000 . In certain embodiments, the cross-connect is performed from a module on a given rack  2000  to a module on the opposite side of the destination rack  2000  as shown in  FIG.  112   . Whether the cabling starts out from a module on the right side  2010  of the rack  2000  or from a module on the left side  2012  of the rack  2000 , the cables  2030  are first lead down through their respective vertical cable guides  2046 ,  2048  to the bottom trough  2054 , and after going through the bottom trough  2054 , the cables  2030  are led up the respective vertical cable guides  2046 ,  2048  to the respective front-to-rear troughs  2024 ,  2026  before being lead to the destination rack  2000 . The slack cabling is taken up by the storage spools  2050  on the right side  2010  of the rack  2000 . 
       FIG.  113    illustrates an example cable routing configuration for an interconnect routing on a single rack  2000 , wherein incoming patch cords  2030  are routed to the modules located on the rack  2000 , the patch cords  2030  incoming from the top  2036  of the rack  2000 . The patch cords  2030  are normally routed from above the rack  2000  to a module on the opposite side of the rack  2000 . The patch cords  2030  are lead downwardly through the respective vertical cable guides  2046 ,  2048  and through the bottom trough  2054 . After going around the anchor spool  2056  adjacent the right side  2010  of the rack  2000 , the patch cords  2030  are terminated to modules at opposite sides of the rack  2000  from where they first entered the rack  2000 , as shown in  FIG.  113   . The slack cabling  2030  is taken up by the storage spools  2050  on the right side  2010  of the rack  2000 . 
       FIG.  114    illustrates an example method of managing cable slack for cables  2030  routed within the rack  2000  of  FIG.  100   . For example, as seen in the example method in  FIG.  114    and as discussed above with respect to the various front cable routing configurations, the patch cord  2030  may be routed around the appropriate storage spool  2050  (e.g., the highest possible spool) at the right side  2010  of the rack  2000  after the patch cord  2030  has been terminated and has been extended as far as it can reach. 
     Referring now to  FIGS.  115 - 118   , one example embodiment of a splice chassis that may be used as part of the telecommunications rack  2000  and the associated cable routing around the splice chassis is illustrated. 
     The splice chassis will be described such that the terms “right” and “left” will be used to refer to the right and left sides of the chassis when looking directly at the splice chassis (i.e. when a person is standing in front of the splice chassis). 
       FIG.  115    shows a perspective view of the bottom portion of the rack  2000  that is configured to hold telecommunications equipment. As noted above, the rack  2000  includes a splice region  3110  at which one or more splice cassettes may be stored on the rack  2000 . In some implementations, the splice region  3110  is disposed beneath a termination region of the rack  2000 . In certain implementations, the splice region  3110  is disposed towards a bottom of the rack  2000 . In certain implementations, the splice region  3110  is disposed at a “dead zone” beneath all termination regions of the rack  2000 . In certain implementations, the splice region  3110  is located a rear side of the rack  2000 . In certain implementations, one or more covers can extend over the splice region  3110  to inhibit access to and/or to protect the splice region  3110 . In certain implementations, the one or more covers can be fastened in place to protect components at the splice region  3110 . 
     In the example shown, a sliding drawer, blade, or other frame  3112  is mounted to the rack  2000  at the splice region  3110 . The sliding frame  3112  includes one or more compartments or zones  3114  at which the splice cassettes  3200  may be disposed. The frame  3112  may be slid relative to the rack  2000  from a stowed position to an extended position to provide access to the splice cassettes  3200  disposed in the zones  3114 . For example, the frame  3112  may include guides along which the frame  3112  slides. In certain implementations, the splice cassettes  3200  are more accessible from a rear of the rack  2000  when the frame  3112  is slid to the extended position and are less accessible from the rear of the rack  2000  when the frame  3112  is slid to the stowed position. In certain implementations, the rack  2000  inhibits access to the splice cassettes  3200  when the frame  3112  is in the stowed position within the rack  2000 . 
     In some implementations, the zones  3114  are arranged in a T-shaped configuration on the frame  3112  (see  FIG.  117   ). In the example shown, the zones  3114  include a first zone  3114   a  that extends horizontally across the rack  2000 . The first zone  3114   a  is configured to hold one or more splice cassettes  3200  in a row extending parallel to a sideways axis of the rack  2000 . Forward-rearward facing zones  3114   b ,  3114   c  are disposed at opposite ends of the first zone  3114   a . Each forward-rearward facing zone  3114   b ,  3114   c  is configured to hold one or more splice cassettes  3200  in a row extending parallel to a forward-rearward axis of the rack  2000 . These three zones  3114   a - 3114   c  form the cross-member of the “T” of the frame  3112 . Behind the first zone  3114   a  (i.e., closer to the front of the rack  2000 ) additional forward-rearward facing zones  3114   d ,  3114   e  can be disposed. These zones  3114   d ,  3114   e  form the base of the “T” of the frame  3112 . In other implementations, however, the sliding frame  3112  may include a greater or lesser number of zones  3114  arranged in various other configurations. 
     In general, the splice cassettes  3200  are configured to stack or otherwise fit together so that a bottom major surface of one splice cassette  3200  engages a top major surface of another splice cassette  3200 . An end of each splice cassette  3200  seats on the frame  3112 , as discussed further in U.S. Pat. No. 9,348,105, that has been incorporated by reference in its entirety. 
     The frame  3112  may include flat panels or flanges that extend upwardly at opposite ends of one or more of the stacks to retain the splice cassettes  3200  within the frame  3112 . In other implementations, the splice cassettes  3200  may be stacked so that a major side or elongated edge of one or more of the splice cassettes seats on the frame  3112 . 
       FIG.  116    shows one example implementation of the sliding frame  3112  in isolation from the frame  2000  and with the splice cassettes  3200  removed. The sliding frame  3112  is configured for high-density applications. In some implementations, the frame  3112  can accommodate up to forty-eight splice cassettes, each with a capacity of up to six mass fusion splices, which each splice having twelve fiber ribbons (i.e., seventy-two spliced fibers), for a total capacity of 3,456 splices per frame  3112 . In other implementations, the frame  3112  can accommodate a greater or lesser number of splice cassettes  3200 . In other implementations, the splice cassettes  3200  can accommodate a greater or lesser number of splices. 
     In some implementations, each zone  3114  includes spaced apart flanges  3118  that define cassette slots  3119  therebetween. In some implementations, each cassette slot  3119  defines a space sized to receive a single splice cassette  3200 . In other implementations, each cassette slot  3119  defines a space sized to receive multiple splice cassettes  3200 . In certain implementations, each cassette slot  3119  is aligned with at least one lancing section  3115 . In other implementations, at least one of the lancing sections  3115  is accessible from each cassette slot  3119 . The flanges  3118  and slots  3119  are sized and shaped to receive the cassettes  3200  so that the cassettes  3200  stand along narrow edges of the cassettes  3200 . 
     The frame  3112  includes one or more lancing sections  3115  (e.g., at tie-off points) at which optical fibers or cables can be secured when routed to the splice cassettes  3200 . The fibers or cables can be anchored to the lancing sections  3115  by waxed lacing or other cable securement fasteners. In certain implementations, the incoming cables are secured to the lancing sections  3115  as the incoming cables enter the cassettes  3200 . In the example shown in  FIG.  117   , a first lancing section  3115   a  extends along the front zone  3114  out of view in  FIG.  116   . A second lancing section  3115   b  is disposed at a first end of the front compartment  3114   a  adjacent the second zone  3114   b , and a third lancing section  3115   c  is disposed at a second end of the first compartment  3114   a  adjacent the third zone  3114   c . Fourth and fifth lancing sections  3115   d ,  3115   e  are disposed between the additional forward-rearward facing zones  3114   d ,  3114   e.    
     In some implementations, the rack  2000  defines a storage area  3116  beneath the splice region  3110  (e.g., see  FIGS.  115 ,  117 , and  118   ). In certain implementations, the storage region  3116  is disposed at a floor on which the rack  2000  seats. In certain implementations, the storage region  3116  has a width that generally matches a lateral distance across the fourth and fifth zones  3114   d ,  3114   e  of the frame  3112 . In certain implementations, the storage region  3116  has a width that generally matches a distance across the first zone  3114   a  of the frame  3112 . In the example shown in  FIG.  117   , the first zone  3114   a  and at least part of the fourth and fifth zones  3114   d ,  3114   e  are disposed over the storage area  3116  when the frame  3112  is in the stowed position. 
     The storage region  3116  is configured to hold cable slack for the cables and fibers (e.g., network cables, distribution cables, etc.) entering and exiting the splices held at the splice region  3110 .  FIG.  117    shows a top plan view of the storage region  3116 . One or more bend radius limiters  3119  are disposed within the storage area  3116 . In the example shown, one bend radius limiter  3119  is disposed at a first side of the storage area  3116  and another bend radius limiter  3119  is disposed at an opposite second side of the storage area  3116 . The bend radius limiters  3119  are accessible from the rear of the rack  2000  when the frame  3112  is disposed at the extended position. The frame  3112  blocks access to the limiters  3119  from the rear of the rack  2000  when the frame  3112  is disposed at the stowed position. 
     As shown in  FIG.  118   , cables  3300  that are to enter and exit the splice cassettes  3200  are routed from a bottom of the frame  3100  into the storage area  3116  below the splice region  3110 . In the example shown, the cables  3300  are routed from one side of the frame. The cables  3300  are routed between the two bend radius limiters  3119  (see points A in  FIG.  118   ) and up to the sliding frame  3112 . In some implementations, the cables  3300  are disposed within the storage area  3116  when the frame  3112  is in the rear position. In particular, the slack length of the cables  3300  extends into the storage area  3116 , extends between and loops around the bend radius limiters  3119 , and extends up to the frame  3112 . In some implementations, sliding the frame  3112  to the extended position provides access to the storage area  3116  from the rear of the rack  2000 . As the frame  3112  is slid to the extended position, the cable slack lengthens out (e.g., unfolds from around the bend radius limiters  3119 ). 
     In some implementations, the cables  3300  can be routed onto the frame  3112  through guides (e.g., vertically extending bend radius limiters)  3117  and into channels  3113  defined between the zones  3114 . In certain implementations, the guides  3117  are disposed where the base of the “T” of the frame  3112  and the cross-member of the “T” of the frame  3112  meet. In certain implementations, the guides  3117  are located generally above the bend radius limiters  3119  when the frame  3112  is in the stowed position. In some implementations, the cables  3300  are branched into fibers or groups of fibers when the cables  3300  enter from the guides  3117 . The separated fibers or groups of fibers (e.g., ribbons, buffered fibers, upjacketed fibers, etc.) are each routed through the channels  3113  to one of the zones  3114   a - 3114   e . The cables  3300  are tied off at the lancing points  3115  (e.g., see point B in  FIG.  118   ) that correspond to the desired zone  3114  of the frame  3112 . 
     In the example shown in  FIG.  118   , a first cable  3300  is routed from the right side of the rack  2000 , through the bend radius limiters  3119 , to the left side of the storage area  3116 , beneath the frame  3112 , and to a top of the frame  3112  at a left guide  3117 . Fibers or groups of fibers branching from the first cable  3300  are routed to the second zone  3114   b , fourth zone  3114   d , or left side of the first zone  3114   a  and secured to the corresponding lancing sections  3115   b ,  3115   d ,  3115   a . A second cable  3300  is routed from the right side of the rack  2000 , through the bend radius limiters  3119 , to the right side of the storage area  3116 , beneath the frame  3112 , and to a top of the frame  3112  at a right guide  3117 . Fibers or groups of fibers branching from the second cable  3300  are routed to the third zone  3114   c , fifth zone  3114   e , or right side of the first zone  3114   a  and secured to the corresponding lancing sections  3115   c ,  3115   e ,  3115   a . In some implementations, the cables  3300  are routed straight from the storage area  3116  to the guides  3117 . In other implementations, the cables  3300  are curved or undulated en route to the respective guide  3117  (e.g., see section  3300   a  in  FIG.  118   ). 
     In some implementations, end lengths of the cables  3300  can be removed from the rack  2000  and prepared for splicing within one or more splice cassettes  3200  at a location remote from the rack  2000 . For example, the terminated end of a cable  3300  can be broken out, ribbonized (if initially stranded), and spliced to one or more other cables at a working location that is between 1 foot and fifty feet away from the rack  2000 . In certain implementations, the working location is located within thirty feet of the rack  2000 . In certain implementations, the working location is located within twenty feet of the rack  2000 . In certain implementations, the working location is located within ten feet of the rack  2000 . At least some of the excess slack of the end length of the cable  3300  is taken up by winding the end length around the splice cassettes  3200 , as will be disclosed in more detail below, until the splice cassette  3200  is located at the frame  3112 . 
       FIG.  119 - 124    illustrate another embodiment of a telecommunications rack  4000  including features similar to those of the telecommunications rack  2000  shown in  FIGS.  100 - 118   . 
     In  FIG.  119   , the telecommunications rack  4000  is shown from a top, front, left side perspective view. In  FIG.  120   , the telecommunications rack  4000  is shown from a top, rear, right side perspective view.  FIG.  121    illustrates a front view of the telecommunications rack  4000 .  FIG.  122    illustrates a top view of the telecommunications rack.  FIG.  123    is a rear view of the telecommunications rack.  FIG.  124    is a left side view of the telecommunications rack. 
     It should be noted that, similar to the orientation used for the rack  2000 , the terms “right” and “left” are used to refer to the right and left sides  4014 ,  4016  of the rack  4000  when looking at the rack  4000  from a rear view thereof (i.e. when a person is standing at the rear  4006  of the rack  4000 ). 
     Still referring to  FIGS.  119 - 124   , as noted above, the rack  4000  includes features similar to the rack  2000  except for a number of differences which will be discussed herein in detail. 
     The rack  4000 , similar to rack  2000 , includes front-to rear troughs  4008  that communicate with rear horizontal troughs  4010  at the rear  4006  of the rack  4000 . Cable loops  4012  are provided adjacent both the right and left sides  4014 ,  4016  of the rack  4000 . 
     Unlike rack  2000 , rack  4000  defines a storage bay  4018  at the front  4020 , right side  4014  thereof that includes cable storage and management features at both the front and the rear sides  4020 ,  4006  of the rack  4000 . The first version of the rack  2000 , instead, utilizes cable slack management spools (i.e., spools  2050  of rack  2000 ) in a stacked configuration only at the front, right side of the rack  2000 . 
     The storage bay  4018  that is configured to provide for cable management and cable slack storage at both the front and the rear sides  4020 ,  4006  of the rack  4000  is configured such that it can be retrofitted to a first embodiment of the rack  2000  if the spools  2050  are removed from the rack  2000 . The storage bay  4018  is configured to communicate with an upper trough  4022  that is located at the top  4024  of the rack  4000 . The upper trough  4022 , as will be discussed in further detail below, is configured for guiding cabling through the trough  4022  to other racks  4000  of similar configuration to rack  4000  across an aisle in a rack storage facility (see e.g.,  FIGS.  125 - 126   ) and/or guiding cables  4032  down to the storage bay  4018  for coupling to modules located within panels on the rack  4000 . 
     Referring now specifically to the storage bay  4018 , the storage bay  4018  defines both a front cable storage area  4026  and a rear cable storage area  4028 . The front cable storage area  4026  is divided into a cable feed section  4030  that is configured for guiding cables  4032  incoming from the upper trough  4022  and a slack storage section  4034  that is configured for guiding cables  4032  from the cable feed section  4030  to the modules on the rack  4000 . The cable feed section  4030  defines a plurality of cable management fingers  4036  for keeping the cables  4032  therein. The slack storage section  4034  defines a plurality of cable management fingers  4038  for keeping the cables  4032  therein and a plurality of cable management spools  4040  stacked along a vertical row for taking up slack cabling when leading cables  4032  from the cable feed section  4030  to the modules on the rack  4000 . The spools  4040  are similar in configuration and function to the spools  2050  of the first embodiment of the rack  2000 . 
     From the spools  4040  in the slack storage section  4034  of the bay  4018 , cabling  4032  may be lead around an anchor spool  4042  provided adjacent the bottom  4044  at the front  4020 , right side  4014  of the rack  4000 , which is similar to that of rack  2000 . After passing around the anchor spool  4042 , the cable  4032  may be lead upwardly, passing through cable loops  4012  that are located at either the right side  4014  or the left side  4016  of the rack  4000  depending upon which side of the panel the cable  4032  needs to be plugged in on the rack  4000 . An example cable routing configuration wherein a cable  4032  is lead upwardly through cable loops  4012  on the right side  4014  of the rack  4000  and plugged in to a module at the right side  4014  of the rack  4000  is shown in  FIG.  121   . 
     Referring now to  FIGS.  120  and  123   , as discussed above, the rear cable storage area  4028  of the storage bay  4018  also includes a cable feed section  4046  and a slack storage section  4048 . The cable feed section  4046  includes a plurality of cable management fingers  4050  similar to the cable feed section  4030  of the front cable storage area  4026  of the bay  4018 . The slack storage section  4048  of the rear cable storage area  4028  defines a plurality of cable management spools  4052  arranged along a vertical row similar to the spools  4040  at the front cable storage area  4026 . A first anchor spool  4054 , similar to the front anchor spool  4042 , is also located adjacent the bottom  4044  of the rack  4000  within the slack storage section  4048 . Additionally, the slack storage section  4048  further includes a second anchor spool  4055  that cooperates with spools  4052  in taking up the cable slack as will be described in further detail below. 
     An example cable routing is shown for an incoming cable  4032  (e.g., an equipment jumper) routed to the modules located on the rack  4000 . In the illustrated example, the cable  4032  comes in from a top side  4024  of the rack  4000 . In the example shown, the cable  4032  is routed downwardly through the cable feed section  4030  and around the first anchor spool  4054  at the bottom  4044  of the rack  4000 . From the first anchor spool  4054 , the cable  4032  may be guided upwardly and over the appropriate cable management spool  4052  depending upon the height of the panel that the cable  4032  may be plugged into and the amount of cable slack. After extending around a given cable management spool  4052 , the cable  4032  extends downwardly, around the second anchor spool  4055 , and then upwardly toward the modules. 
     Similar to the routing at the rear side of the first version of the rack  2000 , in the routing at the rear side of rack  4000 , the cable  4032 , if being terminated at the right side  4014  of the rack  4000 , is routed through a second trumpet flare  4056  and into a module at the right side  4014  of the rack  4000  (please refer to  FIG.  104   ). If the cable  4032  is being terminated at the left side  4016  of the rack  4000 , the cable  4032  is routed through a crossframe trough  4058  (similar to crossframe trough  2014  of rack  2000 ), around a spool  4060  (similar to spool  2020  of rack  2000 ), and into one of the modules within a panel at the left side  4016  of the rack  4000  (please refer to  FIG.  104   ). 
     As shown in  FIGS.  120  and  123   , in addition to including a rear cable storage area  4028  that is not provided in the first embodiment of the rack  2000 , the rack  4000  also includes a plurality of rear horizontal trough extensions  4062  that are configured to be aligned with the rear horizontal troughs  4010  of the rack  4000 . The rear horizontal troughs  4010  of rack  4000 , as noted above, are similar to the rear horizontal troughs  2022  of rack  2000 . The rear horizontal trough extensions  4062  of rack  4000  provide an extension to the rear horizontal troughs  4010  at the right side  4011  of the troughs  4010 . 
     As discussed above for the first embodiment of the rack  2000  and illustrated in  FIG.  112   , the rear horizontal troughs  4010  may be used for routing a cable  4032  between two telecommunications racks  4000  that are positioned side to side. As shown in the example configuration in  FIG.  112   , once the proper patch cord length is determined, a cable  4032  from either a module on the left side  4016  or a module on the right side  4014  may be routed through a respective front-to-rear trough  4008  to the rear horizontal trough  4010  to a destination rack  4000 . 
     Referring now to  FIGS.  125  and  126   , as noted above, the storage bay  4018  of rack  4000  may define an upper trough  4022  that is located at the top  4024  of the rack  4000 . The upper trough  4022  defines a drop-off portion  4064 , a front opening  4066 , and a rear opening  4068 . 
     The upper trough  4022  may be used to guide cables  4032  down the cable feed section  4030  of the front cable storage area  4026  at the front side  4020  of the rack  4000  as discussed above and as shown in  FIGS.  121  and  122   . The cables  4032  may be fed from the upper trough  4022  to the cable feed section  4030  using the drop-off portion  4064  of the upper trough  4022 . 
     As noted above, the upper trough  4022  may also be used to guide cables  4032  between racks  4000  of similar configuration across an aisle in a rack storage facility (see e.g.,  FIGS.  125 - 126   ). For example, as seen in  FIGS.  125  and  126   , if cabling  4032  is extended between two racks  4000 , the rear openings  4068  of the upper troughs  4022  may be closed-off since not utilized. Otherwise, the upper troughs  4022  may be used as through troughs wherein the drop-offs  4064  may be bypassed and cabling  4032  extended out the rear openings  4068 . 
     As shown in  FIGS.  125  and  126   , the upper trough  4022  provides the ability to guide cables  4032  across an aisle in a rack storage facility (between two racks positioned front to front, front to back, or back to back) without sacrificing connectivity rack space. All of the cross-aisle cabling is provided at the tops  4024  of the racks  4000 , without sacrificing any panel mounting space within the racks  4000 . 
     As also shown in  FIGS.  125  and  126   , the storage bay  4018  is configured such that the upper trough  4022  of the storage bay  4018  may be retrofit to existing cable guiding structures for guiding cable across an aisle between two racks  4000 . For example, in  FIGS.  125  and  126   , the upper trough  4022  is shown coupled to a cross-aisle pivot trough  4070  that might extend across the aisle between two racks  4000 . A structure such as the cross-aisle pivot trough  4070  is designed to accommodate an offset between the front openings  4066  of two upper troughs  4022  of two racks  4000  that are positioned face to face for crossing the cable  4032  across the aisle. 
     In an example configuration that is available from TE Connectivity under the model name X-Aisle Trough System, a cross-aisle pivot trough  4070  may be mounted at a first end  4072  to a first upper trough extension  4074  and may be mounted at a second end  4076  to a second upper trough extension  4078 . The first upper trough extension  4074  is coupled to the upper trough  4022  of a first rack  4000  and extends out from the front opening  4066  of the upper trough  4022  of the first rack  4000 . The second upper trough extension  4078  is coupled to the upper trough  4022  of a second rack  4000  that is across the aisle from the first rack  4000  and extends out from the front opening  4066  of the upper trough  4022  of that second rack  4000 . The cross-aisle trough  4070  is pivotally coupled to the first and second upper trough extensions  4074 ,  4078  so that different offsets between the racks  4000  may be adjusted for. The pivotable cross-aisle trough  4070  is mounted to the first and second upper trough extensions  4074 ,  4078  at first and second pivot mounts  4080 ,  4082 . The pivot mounts  4080 ,  4082  provide for a curved-track/pin arrangement in providing the ability for the cross-aisle trough  4070  to be pivotally adjusted with respect to the upper trough extensions  4074 ,  4078 . 
     The cross-aisle trough  4070  is structurally supported by first and second support bars  4084 ,  4086  that extend between the pivot mounts  4080 ,  4082  and the respective racks  4000 . The support bars  4084 ,  4086  are fastened to the upper cross frame member  4088  of the racks  4000  that extends between the right and left sides  4014 ,  4016  of a rack  4000 . The upper cross frame member  4088  of the racks  4000  defines a plurality of fastener holes  4090  for providing adjustability for the support bars  4084 ,  4086  for coupling any two given racks  4000 . 
     Although in the foregoing description, terms such as “top,” “bottom,” “front,” “back,” “right,” “left,” “upper,” and “lower” were used for ease of description and illustration, no restriction is intended by such use of the terms. The telecommunications devices described herein can be used in any orientation, depending upon the desired application. 
     Having described the preferred aspects and embodiments of the present invention, modifications and equivalents of the disclosed concepts may readily occur to one skilled in the art. However, it is intended that such modifications and equivalents be included within the scope of the claims which are appended hereto.