Abstract:
A connector module is provided that includes a longitudinal body adapted for installation in a computer equipment rack capable of housing a plurality of server units positioned in a stack configuration. The longitudinal body has a plurality of data connectors mounted along an outer surface. Each data connector is located at a different location along the outer surface of the longitudinal body and is adapted to receive a signal source introduced from a front side of the outer surface. The connector module includes a collection of signal paths coupled to the plurality of data connectors. Signal paths are positioned toward a backside of the outer surface. The longitudinal body is adapted for installation in a transverse orientation relative to the plurality of server units in the stack configuration such that each data connector is positioned in proximity to a connector mounted on a corresponding one of the server units.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application is related to co-owned and co-pending U.S. patent application Ser. No. 11/______, attorney docket number 026529-000300US, which is hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Rack mount systems are standardized systems for mounting electronic equipment such as computer servers in a vertical, stacked configuration. For example, a common standard rack mount system is the 19 inch rack system (Electronic Industries Alliance—EIA 310-D) so named because the overall rack width in the system is 19 inches. A rackmount system typically comprises a cabinet with an open front and back which allows access to electronic components mounted in the rackmount system and encourages dissipation of excess heat from the electronic devices. A typical rackmount system, such as a 19-inch rack system, includes a set of parallel rails that runs vertically along the front of the cabinet. The rails are pierced at regular intervals with mounting holes for mounting electronic devices, and electronic devices are generally mounted in the rackmount system by fastening the electronic device to the rails via bolts or via a set of clips attached to the electronic device. 
         [0003]    The mounting holes in the rails of a typical 19-inch rackmount system are positioned in groups of three. Each group of three mounting holes is spaced apart in 1.75 inch increments referred to as “units” (sometimes written as “U”). Generally, a rackmount electronic device is sized to according the number of units of vertical space that the device requires. For example, a rackmount server may be three units high while a switch may be two units high. If both devices are to be mounted in the same rackmount system, a total of five units of free space would need to be available in the rackmount system. 
         [0004]    An electronic device in a rackmount system often must communicate with other electronic devices in the rackmount system. Data cables are typically used to carry data signals between the electronic devices. As the number of components in the rackmount system increases, the number of and length of the data cables can make the cables difficult to maintain. One solution is to bundle cables together and/or use cable harnesses when routing data cables through the rackmount system. However, the cables still must be custom cut to the proper length by hand, and tracking down of faults in the system can become extremely difficult. 
         [0000]    Furthermore, the data cables themselves can add latency to data communications between components. As the length of data cables increases, electrical signals must travel across longer lengths of cable which not only increases the length of time that signals take to reach their destination, but may also increase the likelihood of distortion, noise, and/or interference detrimentally affecting signal quality. 
         [0005]    Blade server systems provide one alternative to rack-mount server systems. Blade servers are self-contained computer servers with a small profile that enables a large number of servers to be installed in a smaller space. Blade servers typically have a smaller profile than rackmount servers, because blade servers do not include a number of components typically included in typical rack-mount servers such as separate cooling components, power supplies, and networking components. Unlike typical rackmount servers, blade servers rely upon a blade server enclosure to provide services such as power, network connectivity, and cooling. Thus, blade server systems require specialized electronic devices designed to operate with blade server systems, and typical rackmount devices such as rackmount computer servers are not compatible with blade server systems. Therefore, blade server systems are not always adequate solution for implementing computer server systems. 
         [0006]    A solution adapted to use rackmount electronic devices while decreasing the number and length of data cables required to interconnect electronic devices in a typical rackmount system is required. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    The present invention provides a system for interconnecting rack-mounted electronic components such as rack mounted computer servers. The system provides an interconnect strip comprising a connector module including a plurality of data connectors which may be coupled to rack mounted electronic component and also includes a plurality of data signal paths interconnecting the plurality of data connectors to enable data communications between the rack mounted electronic components coupled to the data connectors. 
         [0008]    Embodiments of the present invention advantageously decrease both the length and number of cables needed to interconnect rack mounted electronic components. Furthermore, in some embodiments, the interconnect strip enables optical connections between components. Optical connections via optical fiber permit digital communications over larger distances and at higher data rates than electronic components. In some embodiments, the system provides electrical-optical transceivers for receiving an optical signal via an uplink port and transmitting electrical signals across the plurality of data signal paths of the interconnect strip and vice versa. In other embodiments the system is adapted to receive electrical signals via an uplink port and convert the electrical signals to optical signals with an electrical-optical transceiver. In yet other embodiments, the system provides electrical-optical transceivers integrated into the interconnect strip for receiving electrical data signals from rack mounted devices and transmitting optical signals across the plurality of data signal paths of the interconnect strip and vice versa. In other embodiments, the electrical-optical transceivers are built into rack mounted electronic components and the rack mounted electronic components are coupled to the interconnect strip via an optical connection. 
         [0009]    In an embodiment of the present invention, a connector module is provided. The connector module includes a longitudinal body adapted for installation in a computer equipment rack that is capable of housing a plurality of server units positioned in a stack configuration. The longitudinal body has a plurality of data connectors mounted along an outer surface. Each of the data connectors is located at a different location along the outer surface of the longitudinal body and is adapted to receive a signal source introduced from a side of the outer surface. The connector module also includes a collection of signal paths coupled to the plurality of first data connectors. The signal paths are positioned affixed to the longitudinal body. The longitudinal body is adapted for installation in a transverse orientation relative to the plurality of server units in the stack configuration in order to position each of the first plurality of data connectors in proximity to a connector mounted on a corresponding one of the plurality of server units. 
         [0010]    Other features and advantages of the invention will be apparent in view of the following detailed description and preferred embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a block diagram of prior art rackmount servers. 
           [0012]      FIG. 2  is a block diagram of a prior art rackmount system. 
           [0013]      FIG. 3  is block diagram of a prior art rack mount server. 
           [0014]      FIG. 4  is a block diagram of a prior art blade server. 
           [0015]      FIG. 5  is a block diagram of a prior art blade server system. 
           [0016]      FIGS. 6A and 6B  are a block diagram of a rackmount system including an interconnect strip according to one embodiment of the present invention. 
           [0017]      FIG. 7  is a block diagram of a rackmount system including a passive electrical interconnect strip according to one embodiment of the present invention. 
           [0018]      FIG. 8  is a block diagram of a rackmount system including an active optical interconnect strip according to one embodiment of the present invention. 
           [0019]      FIG. 9  is a block diagram of a rackmount system including an active electrical interconnect strip according to an embodiment of the present invention. 
           [0020]      FIG. 10  is a block diagram of a rackmount system including an active optical interconnect strip with electrical-optical conversion according to an embodiment of the present invention. 
           [0021]      FIG. 11  is a block diagram of a rackmount system including an active electrical and optical interconnect strip with optical uplink ports according to an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0022]    Embodiments of the invention are described here, with reference to the figures. Where elements of the figures are called out with reference numbers, it should be understood that like reference numbers refer to like elements and might or might not be the same instance of the element. 
         [0023]      FIG. 1  is a block diagram of prior art rackmount systems. Rackmount systems  111  and  122  are connected by a data cable  150  which is coupled to rackmount system  111  via data connector  140  and coupled to rackmount system  122  via data connector  145 . Data cable  150  enables electronic devices mounted in rackmount system  111  to communicate with electronic devices mounted in rackmount system  122  and vice versa. Data cable  150  carries electrical data signal. Data cable  150  may comprise any cable adapted to carrying electrical data signals, such as twisted pair or coaxial cable. 
         [0024]      FIG. 2  is a block diagram of typical prior art rackmount system. Rackmount system  200  comprises an external cabinet including a set of rails for mounting a plurality of electronic components. As described above, the electronic components generally must be a minimum of 1U high. Many rack-mount electronic components are a multiple of 1U high. For example, a rack-mount server unit may be 3U high. A typical approach for interconnecting electronic devices mounted in the rackmount system is to use jumper cables. For example, in some implementations, the rackmount system includes a plurality of server systems. Each of the server systems is connected to a central switch, such as an Ethernet switch, via a data cable. Each of the data cables must be cut to the appropriate length and routed through the rackmount system by hand. Cables may be secured together and routed through the server system in a cable bundle or by using a cable harness. Conventional cables such as these cannot be used effectively when data rates increase past 10 gigabits per second. 
         [0025]    Rackmount system  200  includes a plurality of computers servers  210   a - 210   n , network switch  230 , and management switch  240 . Computer servers  210   a - 210   n  are conventional rack-mount servers. Network switch  230  provides network connectivity for the various electronic components mounted in rackmount system  200 . Network switch  230  may use a variety of networking mediums for connecting devices, such as Ethernet, PCI-Express, InfiniBand, Fibre Channel, ATM, and/or other networking mediums. For example, network switch  230  may be an Ethernet switch coupled to the plurality of computer servers  210   a - 210   n  via Ethernet connections. 
         [0026]    Management switch  240  provides an interface that allows a user to control rack-mounted electronic devices such as computer servers  210   a - 210   n . Management switch  240  may be adapted for switching a plurality of control signal types. In some embodiments, management switch  240  comprises an Ethernet management switch where control signals are transmitted over an Ethernet management connection. For example, the control signals may include keyboard-video-mouse (KVM) signals that enable a user to control various rack-mounted component from a single keyboard, video monitor, and mouse. In a typical rackmount system, a separate Ethernet management connection and Ethernet data connection will generally be provided. Ethernet management connections provided for transmitting control signals will generally be slower than Ethernet data connections provided for transmitting data. For example, a 10 gigabit per second Ethernet data connection may be provided for transmitting data to and from the various rack-mounted components, while a 1 gigabit per second Ethernet management connection is provided for transmitting control signals. 
         [0027]    In other embodiments, management switch  240  may, for example, comprise a keyboard-video-mouse (KVM) switch that provides a user interface that allows a user to control computer servers  210   a - 210   n  from a single keyboard, video monitor, and mouse. KVM switches are often used in rackmount systems where a dedicated set of input and output (I/O) devices such as a monitor, keyboard and/or mouse are not required for each individual rackmount server. In a typical configuration, a computer display device, a keyboard and a mouse are connected to a KVM switch and the KVM switch is connected to each computer server via a KVM I/O cable. In some implementations, a KVM switch provides a physical selector identifying a particular computer server to be controlled at that time. In alternative embodiments, switching control from one computer server to another may also be implemented as a software switch activated by a set of keystrokes on a keyboard or an input entered via another I/O device connected to the KVM switch. 
         [0028]      FIG. 2  illustrates a typical configuration for a rackmount system wherein an Ethernet switch  230  is included in a bottom position in the rack. In some embodiments, the Ethernet switch may also be located at a top position in the rack or in other locations within the rack in yet other embodiments. Each of the plurality of computer servers  210   a - 210   n  is connected to switch  230  by a data cable. As shown, the plurality of data cables  215   a - n  enables bidirectional data communications between computer servers  210   a - 210   n  and/or switch  230  using electrical signals. The plurality of data cables  215   a - n  may, for example, comprise Ethernet cables. The plurality of data cables couple to the plurality of data connectors  260 . The typical approach for interconnecting electronic components in a rackmount system is to use data cables. 
         [0029]    Here, each cable has to be custom cut to the appropriate length and routed through the rackmount system by hand. Cable bundles harnesses may be created or cable harnesses used to group the cables together to more neatly route the cables through the rackmount system. However, the bundles and/or harnesses consume a lot of space in the rackmount system and locating faults in the system can be very difficult and time consuming. Furthermore, conventional cables become prohibitively expensive when data rates increase beyond 10 gigabits per second. 
         [0030]    Rackmount system  200  includes only a small number of computer servers to illustrate the concepts discussed herein. As discussed above, a typical rackmount system may include a large number of servers and/or other electronic devices. Thus, the number and length of cables may become both unwieldy and unmanageable as the number of electronic devices increases. The rackmount system provided by the present invention overcomes these and other problems. 
         [0031]      FIG. 3  is a block diagram of a typical rackmount server. Server  300  includes CPU  310 , random access memory  320 , network card  330 , and data connector  360 . Server  300  also includes outer case  350  adapted for mounting server  300  into a rackmount system such as the one described in  FIG. 2  above. Server  300  may also in some embodiments include a persistent memory for storing data such as a flash memory, a hard disk drive, an optical medium such as a DVD or CD, or other persistent memory or a combination of persistent memory types. CPU  310  executes application and/or operating system programs which may be stored at least in part in memory  320  and/or in a persistent memory either onboard or off-board server  300 . CPU  310  may also read data from and write data to random access memory  320  while executing application and/or operating system programs. CPU  310  is connected to memory  320  via data bus or other communication link. CPU  310  is also connected to network card  330  via a data bus or other communication link. Network card  330  provides network connectivity to server  300  by transmitting and/or receiving data signals across an external network connection. In some embodiments, network card  330  is an Ethernet card. Network card  330  is coupled to data connector  360  which is adapted to connect to an external communications medium, such as an Ethernet cable or an optical fiber. 
         [0032]      FIG. 4  is a block diagram of a prior art blade server  400 . A blade server is a self-contained computer system. Blade servers typically are more compact than rackmount servers because blade servers rely upon a blade server system  500  (see  FIG. 5 ) to provide a number of services, such as network connectivity, cooling, and power. Because a blade server system  500  provides these services, the components that a typical server would include to provide these services need not be included on the individual blade servers. In some instances, the blade server system also provides access to persistent data storage. Blade server  400  comprises PCB  405 , CPU  410 , memory  420 , and bus interface  430 . Bus interface  430  provides an interface for coupling blade server  400  to one of a plurality of data ports  520  on backplane  505  of blade server system  500 . Backplane  505  provides a plurality of ports for mating to bus interface  430  of a plurality of blade servers  400  to enable data communications between blade server  400  and blade server system  500 . Communications across backplane  505  and between the plurality of blade servers  430  and backplane  505  occur via electrical data signals. 
         [0033]    As noted above, blade server systems such as that depicted in  FIGS. 4 and 5  use specialized hardware. Typical rackmount hardware such as that described in  FIGS. 2 and 3  are generally not compatible with blade server systems. Therefore, the present invention has an advantage over the blade server systems by enabling the use of widely available rack mounted electronic devices. Furthermore the present invention also advantageously uses faster optical connections for data communications between devices in some embodiments. Moreover, some embodiments of the present invention may be used to interconnect blade servers to electronic devices coupled to an interconnect strip. For example, in an embodiment, a plurality of blade servers are coupled together and the plurality of blade servers are also coupled to a network I/O blade. The network I/O blade may then be coupled to the interconnect strip via a data cable coupled to an external connector of the interconnect strip. Thus, rackmount components and other electronic devices coupled to the interconnect strip may communicate with the plurality of blade servers via the internal signal paths of the interconnect strip. 
         [0034]    The present invention addresses many of the problems presented by traditional rackmount and blade server systems by providing an interconnect strip adapted for mounting in a rackmount system.  FIG. 6A  is a block diagram of a front view  600 F of rackmount system  600  including interconnect strip  690  according to one embodiment of the present invention. Rackmount system  600  includes four rack-mounted electronic devices  610   a ,  610   b ,  610   c  and  610   d . Rack-mounted electronic devices  610   a ,  610   b ,  610   c , and  610   d  comprise a variety of rackmount devices, such as server units, storage units, storage controller units, input/output units, shared input/output units, expansion slot units, random access memory (RAM) units, switch units, and/or other electronic devices adapted for mounting in a rackmount server system. 
         [0035]    Rackmount system  600  also includes interconnect strip  690  (not visible in front view) coupled to the back of rackmount system  600 . In alternative embodiments, interconnect strip  690  may be coupled to a side or the front of rackmount system  600 .  FIG. 6B  illustrates a cutaway side view of rackmount system  600 . Interconnect strip  690  includes a plurality of mated data connectors  650  that are adapted to couple to mated data connectors  660  included on rack-mounted electronic device  610   a - 610   d . The plurality of mated data connectors  650  of interconnect strip  690  are regularly spaced along an outer surface of interconnect strip  690  such that rackmount devices of varying sizes may be utilized in rackmount system  600 . For example, the plurality of data connectors  650  of interconnect strip  690  may be spaced 1U apart to enable devices 1U or larger to be able to plug into interconnect strip  690 . 
         [0036]    The present embodiment advantageously eliminates external data cables for interconnecting devices in rackmount system  600 . Instead, interconnect strip  690  includes a plurality of internal signal paths adjacent to and corresponding to each of the plurality of data connectors. The plurality of signal paths are adapted for routing data to and from the plurality of data connectors  650 . The plurality of signal paths may include electrical and/or optical signal transmission mediums. In some embodiments, the plurality of signal paths are bidirectional, while in other embodiments, the plurality of signal paths are unidirectional. The data paths may be adapted to transport data signals in a variety of formats, including Fibre Channel, InfiniBand, Keyboard, Video, Mouse (KVM) signals, Peripheral Component Interconnect-Express (PCI Express), memory access, Ethernet (10 Mb/s, 100 Mb/s, 1 Gb/s) and/or 10 gigabit Ethernet (10 GbE) signals. Various implementations of the interconnect strip and signal paths are describe in  FIGS. 7-10  below. 
         [0037]    In alternative embodiments, rack mounted server units are not directly coupled to the interconnect strip. Instead, rack mounted server units are connected to the interconnect strip via a reduced-length cable. Referring back to  FIG. 2 , a typical rackmount system may include a plethora of data cables connecting electronic components, which can introduce a number of maintenance and performance problems. An embodiment of the present invention advantageously addresses at least the problems with typical rackmount systems described above by utilizing an interconnect strip and reduced-length data cables for coupling electronic devices to the interconnect strip. 
         [0038]      FIG. 7  is a block diagram of a rackmount system  700  including an interconnect strip  790  with a passive electrical system according to one embodiment of the present invention. Interconnect strip  790  performs connects ports passively in a pre-arranged pattern similar to a patch panel. A patch panel is typically a rack-mounted panel that houses a plurality of data cable connections. Typically, shorter patch cables are used to connect electronic devices to the patch panel. For example, one end of a patch cable plugs into a data connector of an electronic device and the other end of the patch cable plugs into one of a plurality of data connectors on a front side of the patch panel. Patch panels allow computer and electrical technicians to quickly set up and modify data paths for select signals. 
         [0039]    System  700  includes rack-mounted devices  710   a - 710   n , switch  730  and management switch  740  mounted in rackmount system  700 . Rack-mounted devices  710   a - 710   n , switch  730  and management switch  740  include a plurality of data connectors  750  for inputting and outputting data signals to and from the various electronic components mounted in rackmount system  700 . Interconnect strip  790  includes a plurality of data connectors  760  on the front side of an outside surface  790 F of interconnect strip  790 . The plurality of data connectors  760  are distributed along the outside surface of interconnect strip  790  at regular intervals corresponding to the spacing of rackmount electronic devices. For example, the plurality of data connectors  760  may be spaced as every 1U or some multiple of 1U where the interconnect strip is designed to be coupled to a conventional interconnect strip system where the rackmount devices are multiples of 1U in height. 
         [0040]    In the present embodiment, the plurality of data connectors  760  are distributed along the front side of an outer surface of interconnect strip  790 . One skilled in the art will recognize that in alternative embodiments of the present invention, the distribution of the plurality of data connectors  760  is not limited to a front side of the outer surface of interconnect strip  790  and that the plurality of data connectors  760  may be distributed along various sides and/or multiple sides of interconnect strip  790 . For example, in an embodiment, the plurality of data connectors  760  may be distributed along a back side of interconnect strip  790 .  FIGS. 8-11  also depict the plurality of data connectors being located on the front side of an outer surface of an interconnect strip. The plurality of the data connectors in the embodiments described in  FIGS. 8-11  also are not limited to the front side of an outer surface of the interconnect strip, and may similarly be distributed along various sides and/or multiple sides of the interconnect strip. 
         [0041]    The plurality of data cables  755  provide an electronic signal propagation medium for transmitting data signals to and from the rack-mounted electronic devices and interconnect strip  790 . One end of each data cable  755  is coupled to one of the plurality of data connectors  750  on the various electronic devices and the other end of each data cable  755  is coupled to one of the plurality of data connectors  760  of interconnect strip  790 . The distribution of the plurality of data connectors  760  enables the plurality data cables  755  to be short, equal length jumpers. Thus, the need to create long and expensive custom-length data cables to interconnect rackmount devices is eliminated. Conventional cables such as twisted-pair Ethernet cable and conventional connectors such as eight position, eight conductors (“8P8C”) modular connectors provide an inexpensive solution made possible by the short distance between the electronic devices and interconnect strip  790  that needs to be spanned. Furthermore, the short cable length eliminates the need for cable bundles and/or cable harnesses to route cables through the rackmount system, which may simplify fault detection by eliminating the tangle of cables present in a typical rackmount system. 
         [0042]    In the embodiment illustrated in  FIG. 7 , interconnect strip  790  includes a passive electronic cabling implementation of the present invention. The plurality of internal signal paths  765  comprises electrical signal media, such as electrical cables, that interconnect the plurality of data connectors  760 . For example, in the present embodiment, rackmount system  700  includes a switch  730 . The plurality of internal signal paths  765  provides connectivity between data connectors  760  of interconnect strip. Therefore, switch  730  and management switch  740  are included to provide switching capabilities to rackmount system  700 . 
         [0043]    In alternative embodiments of the present invention, interconnect strip  790  may include an active electronic cabling implementation to provide additional functionality that would typically be found in one or more rack-mounted components. For example, interconnect strip  790  may incorporate the switching functionality of switch  730  and/or management switch  740 , eliminating the need to include switch  730  and/or management switch  740  in the traditional rackmount space. Integrating the functionality of these components into interconnect strip  790  advantageously conserves rackmount space for other components and simplifies the interconnection of rackmount components by shielding a user of the system from the details of configuring switching functionality. 
         [0044]    In other embodiments of the present invention, an interconnect strip may incorporate additional active functionality. For example, in some embodiments of the present invention the interconnect strip performs signal aggregation and/or translation functions. In one embodiment, incoming signals received by the interconnect strip from rack-mounted electronic devices coupled to the interconnect strip are aggregated onto a single output fiber port  770  for uplinking to a central location. 
         [0045]    In yet other embodiments of the present invention, passive optical signal paths are provided instead of electrical signal paths and rack-mounted resources include optical ports that are coupled to interconnect strip  790  via optical cables. In passive optical embodiments interconnect strip  790 , the plurality of internal signal paths  765  comprise optical data signal paths, such as fiber optic cables, in order to take advantage of the higher data rates provided by optical communications. In passive optical embodiment of interconnect strip  790 , the plurality of data cables  755  provide an optical signal propagation medium, such as a fiber optic cable, for transmitting data signals to and from the rack-mounted electronic devices and interconnect strip  790 . Furthermore, data connectors  750  of the various electronic devices and the plurality of data connectors  760  of interconnect strip  790  are optical data connectors in passive optical embodiments of the present invention. 
         [0046]    As described above, separate management and data connections may be provided in a typical rackmount system. Various embodiments of the present invention may also provide separate management and data connections, while other embodiments provide a single connection for transmitting both data and control signals. For example, according to one embodiment of the present invention, a 100 megabit per second Ethernet data connection and a KVM management connection may be provided. According to another embodiment of the present invention, both the data and management connections may comprise Ethernet connections, but the management connection is a lower bandwidth connection. For example, the data management connection may comprise a 10 gigabit Ethernet connection while the management connection comprises only a 100 megabit per second Ethernet connection. KVM or other control signals are sent over the slower management Ethernet connection. According to yet another embodiment of the present invention, a single high-bandwidth connection is provided for both data and control signals. For example, a 10 Gigabit Ethernet connection may be provided to handle both data and control signals. 
         [0047]      FIG. 8  is a block diagram of a rackmount system  800  including an active optical interconnect strip  890  according to one embodiment of the present invention. Rack-mounted devices  810   a - 810   n  and  840  are mounted in rackmount system  800 . Rack-mounted devices  810   a - 810   n , and  840  include a plurality of data connectors  850  for inputting and outputting optical data signals to and from the various electronic components mounted in rackmount system  800 . Interconnect strip  890  includes a plurality of optical data connectors  860  on the front side of an outside surface  890 F of interconnect strip  890 . The plurality of optical data connectors  860  are distributed along the outside surface of interconnect strip  890  at regular intervals corresponding to the spacing of rackmount electronic devices. For example, the plurality of data connectors  860  may be spaced as every 1U or some multiple of 1U where the interconnect strip is designed to be coupled to a conventional interconnect strip system where the rackmount devices are multiples of 1U in height. Interconnect strip  890  also includes an includes a plurality of internal signal paths  835  comprising optical signal media, such as a waveguide or optical fiber, that interconnect the plurality of data connectors  860 . 
         [0048]    The plurality of data cables  855  provide an optical signal propagation medium for transmitting data signals to and from the rack-mounted electronic devices and interconnect strip  890 . One end of each data cable  855  is coupled to one of the plurality of data connectors  850  on the various electronic devices and the other end of each data cable  855  is coupled to one of the plurality of data connectors  860  of interconnect strip  890 . Each data connector  850  is coupled to an electric-optical transceiver  865  integrated into each of the various rackmount devices. Electrical-optical transceiver  865  receives electrical data signals from the rackmount device into which electrical-optical transceiver  865  is integrated and converts the electrical data signals to optical data signals. Optical signals are transmitted to and received from interconnect strip  890  via data connector  850  which is coupled to data cable  855 . Electrical-optical transceiver  865  also receives optical data signal inputs via data connector  865  and converts the optical data signals to electrical data signals which are provided to the rackmount device into which electrical-optical transceiver  865  is integrated. Electrical-optical transceiver  865  may be implemented in different ways, including that disclosed in concurrently filed U.S. patent application Ser. No. 11/______, attorney docket number 026529-000300US. 
         [0049]    The distribution of the plurality of data connectors  860  enables the plurality data cables  855  to be short, equal length jumpers. Thus, the need to create long and expensive custom-length data cables to interconnect rackmount devices is eliminated. Short, equal length jumpers advantageously provide a consistent, low-latency connection between rackmount devices and the interconnect strip. Conventional fiber optic cables and conventional fiber optic connectors provide an inexpensive solution for spanning the short distance between the various rackmount electronic devices and interconnect strip  890 . Furthermore, the short cable length eliminates the need for cable bundles and/or cable harnesses to route cables through the rackmount system, which may simplify fault detection by eliminating the tangle of cables present in a typical rackmount system. Moreover, the use of optical signals rather than electrical signals further reduces signal distortion for transmitting data to and from the various electronic components coupled to interconnect strip system  890 . 
         [0050]    In some embodiments, incoming signals received by the interconnect strip from rack-mounted electronic devices coupled to the interconnect strip are aggregated onto a single output fiber port  870  for uplinking to a central location. In some embodiments, interconnect strip system  890  also includes active function unit  877 . Active function unit  877  may include at least one or more of the following functionalities: optical switching functionality, signal aggregation functionality, distribution functionality, and electrical-optical (EO) switching functionality which may also include electrical serializer/deserializer (“SERDES”) functionality. Active function unit  877  is illustrated as a single component of interconnect strip  890 , however, active function unit  877  may comprise one or more separate or interconnected components that perform the functions of active function unit  877  described herein. 
         [0051]    Where active function unit  877  includes optical switching functionality, an optical switch is provided that controls the flow of a lightpath between input and output ports on the switch. Optical switches include a plurality of purely optical datapaths. No electrical-to-optical or optical-to-electrical signal conversion of the data signals is performed. The inputs and outputs of the optical switches are purely optical. Note that it is possible that some electronic components may be included in the switch to control optical devices in the switch, but the electronic components are not part of the datapath. 
         [0052]    The optical signal aggregation included in active function unit  877  may, for example, be optical wavelength-division multiplexing (“WDM”). Optical WDM allows for multiple optical carrier signals on a single waveguide optical fiber by using different wavelengths of light to carry different signals. WDM employs an optical multiplexer (MUX) to combine optical signals at different wavelengths into a single waveguide or optical fiber. At the opposite end of the fiber, an optical de-multiplexer (DeMUX) splits the signal at each wavelength apart into individual signals. Systems using optical MUX and DeMUX for WDM can achieve very high bandwidth densities in a single channel. 
         [0053]    The distribution functionality included in active function unit  877  may include bundling of links and/or fan-in/fan-out cables. A fan-in/fan-out cable combines the functionality of a fan-in and fan-out cable. A fan-in cable provides a means for receiving multiple inputs and providing a single output. For example, if a fan-in cable includes four inputs each of which comprise an individual data channel, the fan-in output produces a single output comprising four channels. Thus, a fan-in cable allows multiple devices to communicate with a single device. In contrast, a fan-out cable is configured such that multiple outputs are produced from a single input. A fan-in cable, therefore, allows a single device to output a signal to multiple devices. For example, a fan-out cable including four data channels in the input may branch into four outputs, with each output including a single data channel. A fan-in cable may be used to enable allows multiple devices on a network to communicate using a single network attachment. Furthermore, a fan-out cable may be used to enable a single device to communicate with multiple devices using a single network attachment. A fan-in/fan-out cable combines the functionality of a fan-in cable and a fan-out cable. A fan-in/fan-out cable allows, for example, matrix communication of many-to-many devices using a single network attachment. 
         [0054]    In some embodiments, active function unit  877  includes EO switching functionality. EO switching functionality comprises enhanced electrical packet-based switches that provide an electrical-to-optical (EO) and optical-to-electrical (OE) interface at some of the ports of the switch. Note that while the functionality described herein is referred to as EO switching functionality, the functionality included in active function unit  877  may include both EO and OE functionality. Data is switched electrically but propagates between the switch and compute nodes optically. The EO switching functionality allows interconnect strip system  890  to take full advantage of the capabilities of electrical switches while providing a low power, high-bandwidth signal path between the switch and compute nodes. 
         [0055]      FIG. 9  is a block diagram of a rackmount system including an active electrical interconnect strip according to an embodiment of the present invention. Rack-mounted devices  910   a - 910   n  and  940  are mounted in rackmount system  900 . Rack-mounted devices  910   a - 910   n  and  940  include a plurality of data connectors  950  for inputting and outputting electrical data signals to and from the various electronic components mounted in rackmount system  900 . Interconnect strip  990  includes a plurality of electrical data connectors  960  on the front side of an outside surface  990 F of interconnect strip  990 . The plurality of electrical data connectors  960  are distributed along the outside surface of interconnect strip  990  at regular intervals corresponding to the spacing of rackmount electronic devices. For example, the plurality of data connectors  960  may be spaced as every 1U or some multiple of 1U where the interconnect strip is designed to be coupled to a conventional rackmount system where the rackmount devices are multiples of 1U in height. Interconnect strip  990  also includes an includes a plurality of internal signal paths  935  comprising electrical signal media, such as electrical cables or printed circuit board traces, that interconnect the plurality of data connectors  960 . 
         [0056]    The plurality of data cables  955  provide an electrical signal propagation medium for transmitting data signals to and from the rack-mounted electronic devices and interconnect strip  990 . One end of each data cable  955  is coupled to one of the plurality of data connectors  950  on the various electronic devices and the other end of each data cable  955  is coupled to one of the plurality of data connectors  960  of interconnect strip  990 . 
         [0057]    The distribution of the plurality of data connectors  960  enables the plurality data cables  955  to be short, equal length jumpers. Thus, the need to create long and expensive custom-length data cables to interconnect rackmount devices is eliminated. Short, equal length jumpers advantageously provide a consistent, low-latency connection between rackmount devices and the interconnect strip. Conventional electrical cables and conventional electrical connectors provide an inexpensive solution for spanning the short distance between the various rackmount electronic devices and interconnect strip  990 . Furthermore, the short cable length eliminates the need for cable bundles and/or cable harnesses to route cables through the rackmount system, which may simplify fault detection by eliminating the tangle of cables present in a typical rackmount system. 
         [0058]    In some embodiments, interconnect strip system  990  also includes active function unit  977 . Active function unit  977  may include at least one or more of the following functionalities: switching functionality, signal aggregation functionality, distribution functionality. Active function unit  977  is illustrated as a single component of interconnect strip  990 , however, active function unit  977  may comprise one or more separate or interconnected components that perform the functions of active function unit  877  described herein. 
         [0059]    Where active function unit  977  includes electrical switching functionality, an electrical switch is provided that controls the flow of electrical data signals between input and output ports on the switch. A plurality of datapaths through the switch are provided, the data paths comprising metal and semiconductor pathways. Typical electrical switches are packet-based switches. For example, active function unit  977  may include a 24-port Gigabit Ethernet switch. Packet-based switching allows physical channels to be shared logically by controlling the flow of digital packets between the ports. 
         [0060]    The optical signal aggregation included in active function unit  977  may, for example, be electrical serializer/deserializer (“SERDES”) functionality. In SERDES, a serializer converts a parallel data stream to a serial data stream at a higher rate. For example, if the input is a four-bit wide parallel bus, the output stream is 1-bit wide but transfers bits at a rate four times that of the 4-bit wide parallel bus. A deserializer performs the opposite task of converting the serial data stream back into a parallel stream at the original rate. 
         [0061]    The distribution functionality included in active function unit  977  may comprise bundling of links and/or fan-in/fan-out cables. Fan-in/fan-out cables are described above in  FIG. 8 . 
         [0062]    In some embodiments, electrical-optical (EO) transceiver  965  may receive electrical data signals from the plurality of rackmount devices and/or active function unit  977 . EO transceiver  965  converts the electrical data signals to optical data signals to be output over an optical data connection coupled to optical uplink port  970 . Electrical-optical transceiver  965  also receives optical data signal inputs from data sources external to the rackmount system via data optical uplink port  970  and converts the optical data signals to electrical data signals which are provided to active function unit  977  which may transmit the signals to one or more of the rack-mounted electronic devices. Electrical-optical transceiver  965  may be implemented in different ways, including that disclosed in concurrently filed U.S. patent application Ser. No. 11/______, attorney docket number 026529-000300US. 
         [0063]      FIG. 10  is a block diagram of a rackmount system  1000  including an active optical interconnect strip  1090  with electrical-optical conversion according to an embodiment of the present invention. System  1000  provides electrical-optical transceivers integrated into interconnect strip  1090  for receiving electrical data signals from rack mounted devices and transmitting optical signals across the plurality of data signal paths of the interconnect strip and vice versa. Optical connections within interconnect strip  1090  advantageously permit digital communications over larger distances and at higher data rates than electronic components. Furthermore, electronic devices in rackmount system  1000  are coupled to interconnect strip  1090  via plurality electrical data cables  1055  comprising short, equal-length jumpers that provide a consistent, low-distortion connection between rackmount devices and interconnect strip  1090 . The use of short, equal-length jumpers also eliminates the need to create long and expensive custom-length data cables to interconnect rackmount devices. 
         [0064]    Rack-mounted devices  1010   a - 1010   n  and  1040  are mounted in rackmount system  1000 . Rack-mounted devices  1010   a - 1010   n  and  1040  include a plurality of data connectors  1050  for inputting and outputting electrical data signals to and from the various electronic components mounted in rackmount system  1000 . Interconnect strip  1090  includes a plurality of electrical data connectors  1060  on the front side of an outside surface  1090 F of interconnect strip  1090 . The plurality of electrical data connectors  1060  are distributed along the outside surface of interconnect strip  1090  at regular intervals corresponding to the spacing of rackmount electronic devices. For example, the plurality of data connectors  1060  may be spaced as every 1U or some multiple of 1U where the interconnect strip is designed to be coupled to a conventional rackmount system where the rackmount devices are multiples of 1U in height. Interconnect strip  1090  also includes an includes a plurality of internal signal paths  1035  comprising optical signal media, such as a waveguide or optical fiber, that interconnect the plurality of data connectors  1060 . Each data connector  1060  is coupled to an electric-optical transceiver  1065 . Each electrical-optical transceiver  1065  receives electrical data signals from one of the various rackmount devices via data connector  1060 , converts the electrical data signals to optical data signals, and transmits the optical data signals over the plurality of internal signal paths  1035 . Electrical-optical transceiver  1065  also converts optical data signals received from the plurality of signal paths  1035  to electrical data signals and transmits the electrical data signals to an electronic device coupled to data connector  1060  via data cable  1055 . Electrical-optical transceiver  1065  may be implemented in different ways, including that disclosed in concurrently filed U.S. patent application Ser. No. 11/______, attorney docket number 026529-000300US. 
         [0065]    The plurality of data cables  1055  provide an electrical signal propagation medium for transmitting data signals to and from the rack-mounted electronic devices and interconnect strip  1090 . One end of each data cable  1055  is coupled to one of the plurality of data connectors  1050  on the various electronic devices and the other end of each data cable  1055  is coupled to one of the plurality of data connectors  1060  of interconnect strip  1090 . 
         [0066]    The distribution of the plurality of data connectors  1060  enables the plurality data cables  1055  to be short, equal length jumpers. Thus, the need to create long and expensive custom-length data cables to interconnect rackmount devices is eliminated. Short, equal length jumpers advantageously provide a consistent, low-latency connection between rackmount devices and the interconnect strip. Conventional electrical cables and conventional electrical connectors provide an inexpensive solution for spanning the short distance between the various rackmount electronic devices and interconnect strip  1090 . Furthermore, the short cable length eliminates the need for cable bundles and/or cable harnesses to route cables through the rackmount system, which may simplify fault detection by eliminating the tangle of cables present in a typical rackmount system. 
         [0067]    In some embodiments, interconnect strip system  1090  also includes active function unit  1077 . Active function unit  1077  may include at least one or more of the following functionalities: optical switching functionality, signal aggregation functionality, distribution functionality, and electrical-optical (EO) switching functionality which may also include electrical serializer/deserializer (“SERDES”) functionality. The various functionalities of active function unit  1077  functions are similar to those of active function unit  877  described in detail above. Active function unit  1077  is illustrated as a single component of interconnect strip  1090 , however, active function unit  1077  may comprise one or more separate or interconnected components that perform the functions of active function unit  1077  described herein. 
         [0068]    In some embodiments, electrical-optical (EO) transceiver  1075  may receive electrical data signals from the plurality of rackmount devices and/or active function unit  1077 . EO transceiver  1075  converts the electrical data signals to optical data signals to be output over an optical data connection coupled to optical uplink port  1070 . Electrical-optical transceiver  1075  also receives optical data signal inputs from data sources external to the rackmount system via data optical uplink port  1070  and converts the optical data signals to electrical data signals which are provided to active function unit  1077  which may transmit the signals to one or more of the rack-mounted electronic devices. Electrical-optical transceiver  1075  may be implemented in different ways, including that disclosed in concurrently filed U.S. patent application Ser. No. 11/______, attorney docket number 026529-000300US. 
         [0069]      FIG. 11  is a block diagram of a rackmount system including an active electrical and optical interconnect strip with optical uplink ports according to an embodiment of the present invention. Rack-mounted devices  1110   a - 1110   n  and  1140  are mounted in rackmount system  1100 . Rack-mounted devices  1110   a - 1110   n  and  140  include a plurality of data connectors  1150  for inputting and outputting electrical data signals to and from the various electronic components mounted in rackmount system  1100 . Interconnect strip  1190  includes a plurality of electrical data connectors  1160  on the front side of an outside surface  1190 F of interconnect strip  1190 . The plurality of electrical data connectors  1160  are distributed along the outside surface of interconnect strip  1190  at regular intervals corresponding to the spacing of rackmount electronic devices. For example, the plurality of data connectors  1160  may be spaced as every 1U or some multiple of 1U where the interconnect strip is designed to be coupled to a conventional interconnect strip system where the rackmount devices are multiples of 1U in height. Interconnect strip  1190  also includes an includes a plurality of internal signal paths  1135  comprising electrical signal media, such as electrical cable, and optical signal media, such as waveguides or optical fiber, that interconnect the plurality of data connectors  1160 . 
         [0070]    The plurality of data cables  1155  provide an signal propagation medium for transmitting data signals to and from the rack-mounted electronic devices and interconnect strip  1190 . One end of each data cable  1155  is coupled to one of the plurality of data connectors  1150  on the various electronic devices and the other end of each data cable  1155  is coupled to one of the plurality of data connectors  1160  of interconnect strip  1190 . 
         [0071]    The distribution of the plurality of data connectors  1160  enables the plurality data cables  1155  to be short, equal length jumpers. The benefits provided by the jumpers are discussed above regarding  FIGS. 7-9 . Here, the jumpers may comprise either conventional electrical cables or conventional optical fiber, depending upon whether an optical or electrical connection is being established between an electronic device and the interconnect strip. 
         [0072]    In some embodiments, interconnect strip system  1190  also includes active function unit  1177 . Active function unit  1177  may include at least one or more of the following functionalities: electrical and/or optical switching functionality, signal aggregation functionality, distribution functionality. Active function unit  1177  is illustrated as a single component of interconnect strip  1190 , however, active function unit  1177  may comprise one or more separate or interconnected components that perform the functions of active function unit  1177  described herein. 
         [0073]    Active function unit  1177  may include both electrical and optical functionality in the present embodiment. For example, active function unit  1177  may incorporated optical signal related functionality, such as the functionality of active function unit  877  described above. Similarly, active function unit may also incorporate electrical signal related functionality, such as the functionality of active function unit  977  described above. 
         [0074]    The present embodiment of the invention advantageously allows rack-mounted electronic devices to connect to interconnect strip  1190  via one or more optical and/or electrical cables. For example, rack-mounted device  110   a  includes both optical and electrical data connectors. Data connector  1151  is an optical data connector that is coupled to optical data connector  1161  of interconnect strip  1190  via an optical data cable  1157 . Optical data connector  1161  is coupled to optical internal signal path  1136  which is coupled to active function unit  1177 . Data connector  1152  is an electrical data connector that is coupled to electrical data connector  1162  of interconnect strip  1190  via an electrical data cable  1156 . Electrical data connector  1162  is coupled to electrical internal signal path  1137  which is coupled to active function unit  11177 . 
         [0075]    The present embodiment also provides for electrical, optical, and electrical-optical uplink ports that include EO conversion. The uplink ports provide for handling bidirectional communications to and from rackmount system  1100 . For example, interconnect strip  1190  may include one or more optical uplink ports  1172 . Optical uplink port  1172  is coupled to optical internal signal path  1167  and internal signal path  1167  is also coupled to active function unit  1177 . 
         [0076]    Interconnect strip  1190  may also include one or more electrical uplink ports  1171 . Electrical uplink port  1171  is coupled to electrical internal signal path  1166  and electrical internal signal path  1166  is also coupled to active function unit  1177 . 
         [0077]    Interconnect strip  1190  may also include one or more electrical-optical uplink ports that include EO conversion  1170 . Uplink port  1170  is an optical uplink port. Uplink port  1170  is coupled to EO transceiver  1173 . EO transceivers are described above in greater detail with respect to EO transceiver  1065 . Here EO transceiver  1173  receives optical data signals from uplink port  1170  and converts the optical data signals to electrical data signals. EO transceiver  1173  is coupled to electrical signal path  1165  and EO transceiver  1173  transmits the electrical data signals across electrical signal path  1165  to active function unit  1177 . EO transceiver  1173  also receives electrical data signals from active function unit  1177  and converts the electrical data signals to optical data signals which are output via uplink port  1170 . In other embodiments, uplink port  1170  comprises an electrical data port and EO transceiver  1173  converts electrical data signals received via uplink port to optical data signals and transmits the optical data signals across an optical data path to active function unit  1177  and vice versa. 
         [0078]    The embodiments described above provide an interconnect strip comprising a connector module including a longitudinal body adapted for installation in a computer rack capable of housing a multiple electronic devices such as servers in a stack configuration. The connector module includes a plurality of data connectors mounted on an outer surface. The data connectors are adapted to receive a signal source from one or more of the servers in the computer rack. The signal source may produce signals in a variety of formats known to the art, including KVM signals, InfiniBand signals, Fibre Channel signals, memory access signals, PCI-Express signals, Ethernet (10 Mb/s, 100 Mb/s, 1 Gb/s and 10 gigabit Ethernet) signals, and/or other optical and/or electrical signal types. 
         [0079]    Computer programs incorporating various features of the present invention may be encoded on various computer readable media for storage and/or transmission; suitable media include magnetic disk or tape, optical storage media such as compact disk (CD) or DVD (digital versatile disk), flash memory, and the like. Such programs may also be encoded and transmitted using carrier signals adapted for transmission via wired, optical, and/or wireless networks conforming to a variety of protocols, including the Internet. Computer readable media encoded with the program code may be packaged with a compatible device or provided separately from other devices (e.g., via Internet download). 
         [0080]    Thus, although the invention has been described with respect to specific embodiments, it will be appreciated that the invention is intended to cover all modifications and equivalents within the scope of the following claims.