Abstract:
A deferred maintenance mode for network elements is described, wherein upon failure of one or more resources in a network element, redundant resources are used to preserve functionality. Upon subsequent failure of the redundant resources, function can revert to the first set of resources if those resources have a higher level of functionality. This deferred mode is valuable in situations where it may not be possible to repair failed elements in a timely manner, or if there is a limit upon the amount of backup power available.

Description:
TECHNICAL FIELD 
     The invention relates generally to networks and more particularly to management of network resources. 
     BACKGROUND 
     Network elements, for example, switches and routers, are designed with an assumption that a maintenance strategy will be applied to the network element when resources of the network element fail. In one example, a fault-tolerant system employs redundant resources to provide functionality of the network element for a call over the network until the failed resources can be replaced. Currently, when a fault occurs within a Field Replaceable Unit (“FRU”) on a network element, the network element deactivates the FRU and marks the FRU as “dead”. The network element employs a redundant FRU to provide the functionality of the FRU marked as “dead”. A crafts person arrives at the site of the network element and replaces the dead FRU for a new FRU within a few hours. As one shortcoming, if the redundant FRU fails before the crafts person can arrive at the site to replace the dead FRU, the network element terminates all functionality provided by the network element for connections placed over the network. The crafts person may be unable to arrive at the site of a failed network element for several reasons. These include natural causes, like storms, blizzards, earthquakes, hurricanes, etc. They could also include man-made causes such as terrorist acts, war, protests, and labor disputes. It is desirable that the network elements continue to function as well as possible, even in the event of delayed maintenance actions. 
     In another example, the network element receives periodic manual tuning of parameters of the resources of the network element. For example, a crafts person arrives at the site of the network element to adjust the gain of optical signal components of the network element. As another shortcoming, where the crafts person is unable to arrive at the site of the network element, the optical signal components degenerate into a state of undesired functionality. 
     Thus, a need exists for extending a duration of time in which a network element provides functionality for connections placed over a network when resources of the network element fail. 
     SUMMARY 
     The invention in one implementation encompasses a method. A resource of one or more resources of a network element is employed to provide at least a subset of functionality of the network element when a resource of the one or more resources of the network element operates in a state of reduced, nonzero functionality. 
     Another implementation of the invention encompasses an apparatus. The apparatus comprises a maintenance component that allocates a resource of one or more resources of a network element to provide at least a subset of functionality of the network element when a resource of the one or more resources of the network element operates in a state of reduced, nonzero functionality. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Features of exemplary implementations of the invention will become apparent from the description, the claims, and the accompanying drawings in which: 
         FIG. 1  is a representation of one or more network operation centers, one or more wirecenters, one or more network elements, one or more maintenance components, one or more recordable data storage mediums, and one or more resources. 
         FIG. 2  is a representation of the one or more maintenance components of the apparatus of  FIG. 1 . 
         FIG. 3  is a representation of an exemplary process flow of selecting a resource of the one or more resources based on usability ratings for the resources of the apparatus of  FIG. 1 . 
         FIG. 4  is a representation of an exemplary process flow of providing power to the resources of the apparatus of  FIG. 1 . 
         FIG. 5  is another representation of the apparatus of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Turning to  FIGS. 1 and 2 , the apparatus  100  in one example comprises one or more network operation centers (“NOCs”)  105 , one or more wirecenters  110 , and one or more network elements  115  and  120  of the network  107 . The wirecenter  110  in one example comprises a collection of network elements in a central location that serves the needs of many network users. For example, the wirecenter  110  in one example comprises one or more of: a traditional telecommunications central office, a remote site in a telecommunications network, a cable television headend, a computer room, a wiring closet, an industrial process control room, or a government/military electronic command center. The network elements  115  and  120  in one example comprise one or more maintenance components  125  and  130 , one or more recordable data storage mediums  135  and  140 , one or more resources  145 ,  150 ,  160 ,  165 ,  170 ,  175 ,  180 ,  185 ,  190  and  195 , and one or more power supplies  187  and  189 . The recordable data storage mediums  135  and  140  store one or more fault recovery strategies  205 , one or more overload control strategies  210 , one or more deferred maintenance strategies  215 , one or more metrics of normal resource operation  220 , one or more usability ratings  225 , and one or more past maintenance adjustments  230 , as will be described herein. The resources  145  and  150  comprise one or more computer processors. The resources  160  and  165 , and the resources  170  and  175  respectively comprise one or more redundant elements, for example, one or more active I/O controllers and one or more redundant I/O controllers. The resources  180  and  185  comprise computer boards containing four digital signal processing (“DSP”) chips. The resources  190  and  195  comprise redundant array of independent disk (“RAID”) controllers used for bulk data storage. 
     The maintenance components  125  and/or  130  communicate with the network operation center  105  and one or more of the resources  145 ,  150 ,  160 ,  165 ,  170 ,  175 ,  180 ,  185 ,  190  and  195 . The maintenance component  125  receives one or more notifications to operate in a deferred maintenance mode from the network operation center  105 . In another example, the maintenance component  130  makes a determination to operate in the deferred maintenance mode. In one example, the network element  120  receives one or more maintenance commands from the network operation center  105 . The maintenance component  130  makes a determination that the network operation center  105  is unavailable and/or damaged if a maintenance “command/heartbeat” is not received from the network operation center  105  within a pre-defined duration of time, as will be appreciated by those skilled in the art. The maintenance components  125  and/or  130  communicate with the resources  145 ,  150 ,  160 ,  165 ,  170 ,  175 ,  180 ,  185 ,  190  and  195  to determine if a resource, for example, the resource  160 , operates in a state of reduced, nonzero functionality. In another example, when one DSP chip of the four DSP chips on the resource  180  fails, for example, the computer board, the resource  180  operates in a state of reduced, nonzero functionality. 
     When operating in the deferred maintenance mode, the maintenance components  125  and/or  130  employ the fault recovery strategies  205 , the overload control strategies  210 , and the deferred maintenance strategies  215  to provide at least a subset of functionality of the network elements  115  and/or  120  until maintenance is performed on the network elements  115  and/or  120 . The maintenance component  130  employs the deferred maintenance strategies  215  to select and/or allocate the resources  150 ,  170 ,  175 ,  185  and  195  of the network element  120  to provide a subset of functionality of the network element  120  when a resource, for example, the resource  195 , operates in a state of reduced, nonzero functionality. 
     When a resource of the one or more resources of the network element  120  operates in a state of reduced, nonzero functionality, the management component  130  employs the deferred maintenance strategies  215  to provide as much functionally of the network element  120  as possible for as long as possible (i.e., until maintenance is performed on the network element  120 ). In one example, the management component  130  divides a set of functionality of the network element  120  into a subset of critical functionality and a subset of non-critical functionality. The management component  130  withholds power to one or more resources, for example, the resource  185 , that provide the subset of non-critical functionality and provides power to one or more resources, for example the resources  170  and  175 , that provide the subset of critical functionality. In another example, one DSP chip from the four DSP chips of the resource  185  fails. The management component  130  continues to employ the resource  185 , but reduces an amount of work distributed to the resource  185  based on the failed DSP chip of the resources  185 . 
     In one example, the maintenance components  125  and/or  130  determine a usability rating for each of the resources of the network elements  115  and/or  120  based on the deferred maintenance strategies  215 . The usability rating for a resource is based on a level of functionality available for the resource. The usability rating for the resource indicates an amount of functionality available from the resource, as will be explained herein. The maintenance component  125  determines a usability rating for the resources  145 ,  160 ,  165 ,  180  and  190  from results of performance tests and/or information of the resource from error logs and/or status registers for the resource. In one example, the maintenance component  125  executes one or more performance tests on the resources  145 ,  160 ,  165 ,  180  and  190  of the network element  115  and evaluates one or more results returned from the performance tests. In another example, the maintenance component  125  obtains information of the resources  145 ,  160 ,  165 ,  180  and  190  by monitoring error logs and/or status registers for the resources to determine one or more usability ratings for the resources  145 ,  160 ,  165 ,  180  and  190 . 
     For example, the maintenance component  125  makes one or more comparisons of the results from the performance tests of the resource  180  to one or more metrics of normal results  220  for the performance tests of the resource  180 . The maintenance component  125  quantifies the comparisons to determine a level of functionality available from the resource  180 . In one example, the usability rating is a percentage of the level of functionality available for the resource  180  compared to a normal level of functionality for the resource  180 . In another example, the usability rating is based on the types of functionality available for the resource  180 . The maintenance component  125  employs the usability ratings to select a resource, for example, the resource  165 , of one or more resources, for example, the resources  160  and  165 , of the network element to provide at least the subset of functionality of the network element  115 . For example, the maintenance component  125  compares a usability rating for the resource  160 , for example, a first I/O controller, to a usability rating for the resource  165 , for example, a second I/O controller, to determine which of the resources  160  and  165  has the greatest usability rating. The maintenance component  125  in one example stores the usability ratings for the resources  145 ,  160 ,  165 ,  180  and  190  in the recordable data storage medium  135 . Upon request from the network operation center  105 , the maintenance component  125  employs the usability ratings of the resources  145 ,  160 ,  165 ,  180  and  190  to generate maintenance reports for the network element  115 . 
     In another one example, the maintenance components  125  and/or  130  selectively allocate power to one or more of the resources  145 ,  150 ,  160 ,  165 ,  170 ,  175 ,  180 ,  185 ,  190  and  195  of the network elements  115  and/or  120  based on the deferred maintenance strategies  215  to provide at least a subset of functionality of the network elements  115  and/or  120 . For example, the maintenance component  130  employs the deferred maintenance strategies  215  to reduce power for non-critical resources of the network element  120 , for example, the resource  195 . The maintenance component  130  employs the reduction in power for non-critical resources to provide a level of power to critical resources of the network element  120 , for example, the resources  150 ,  185  and  170 . In one example, the maintenance component  130  withholds power to the non-critical resources of the network element  120  (e.g. the resource  195 ) to extend a duration of time to provide power to the critical resources of the network element  120  (e.g., the resources  145 ,  180  and  190 ), as will be appreciated by those skilled in the art. In another example, the maintenance component  130  employs the power allocation strategy to selectively provide power to resources  150 ,  185  and  195  of the network element  120  to provide at least a subset of functional of the network element  120 . For example, the maintenance component  130  provides power to the resource  185  at a first period of time. The maintenance component  130  withholds power to the resource  185  at a second period of time. The maintenance component provides power to the resource  195  at a third period of time. 
     In yet another example, the maintenance components  125  and/or  130  employ the deferred maintenance strategies  215  to perform one or more maintenance adjustments on one or more parameters of one or more resources  145 ,  150 ,  160 ,  165 ,  170 ,  175 ,  180 ,  185 ,  190  and  195  to provide at least a subset of functionality of the network elements  115  and/or  120 . The maintenance components  125  evaluates one or more past maintenance adjustments for a parameters of the resource  160  to make a prediction for a maintenance adjustment to take on the parameters of the resource  160 . The maintenance component  125  performs the maintenance adjustment based on the predication for the maintenance adjustment for the parameter of the resource  160 . For example, the maintenance component  125  makes an evaluation of past maintenance adjustments for a gain parameter of a radio equipment resource or optical interface. Based on the evaluation, the maintenance component  125  develops a predication of a maintenance adjustment for the gain parameter. The maintenance component  125  adjusts the gain according the predication of the maintenance adjustment. 
     An illustrative description of exemplary operation of the apparatus  100  is presented, for explanatory purposes. 
     Turning to  FIG. 3 , in STEP  305 , the maintenance component  125  receives a notification from the network operation center  105  of the network  107 , for example, a military network, to operate in the deferred maintenance mode. In STEP  310 , the maintenance component  125  determines a usability rating for the resource  160 , for example, an active I/O controller, of the network element and a usability rating for the resource  165 , for example, a redundant I/O controller, of the network element. The usability rating for the resource  160  (e.g., the first I/O controller) is 50%. The resource  160  is unable to process packets that are received too close together in time. The usability rating for the resource  165  (e.g., the second I/O controller) is 100%. In STEP  315 , the maintenance component  125  compares the usability rating for the resource  160  to the usability rating for the resource  165 . In STEP  320 , the maintenance component  125  selects the resource  165  to provide a subset of functionality of the network element  115 . The resource  165  processes packets received over the network  107  regardless of priority-level. For example, the resource  165  processes packets with priority levels of a Private, a Sergeant, and a General. 
     The maintenance component  125  repeats STEPS  310  through  315  and re-determines the usability rating for the resources  160  and  165 . Because of failures subsequent to the last pass through of STEPS  310  through  315 , the usability rating for the resource  160  is now 50%. The usability rating for the resource  165  is 48%. In STEP  325 , the maintenance component  125  selects the resource  160  to provide a subset of functionality of the network component  115  based on the level of functionality available to the resource  160 . The resource  160  processes high priority packets, for example, packets originating from a General on the military network. The resource  160  drops packets originating from a Sergeant and/or a Private. 
     As the resources  160  and  165  continue to degrade due to delayed maintenance actions from a crafts person, the maintenance component  125  repeats STEPS  310  through  315  to re-determine the usability ratings for the resources  160  and  165 . The maintenance component  125  continues to select the resource with the highest usability rating from the usability ratings of the resources  160  and  165 . As a result, the maintenance component  125  employs the usability ratings of the resources  160  and  165  to provide the most network functionality available by performing a selection of a resource with the most remaining functionality from the resources  160  and  165 . The selection of the resource made by the maintenance component  125  may oscillate as the resources  160  and  165  continue to degrade. Advantageously, allowing the selection of the resource made by the maintenance component  125  to oscillate, permits the network element  115  to preserve a maximum possible level of functionality, even as redundant I/O elements, for example, the resources  160  and  165 , experience multiple failures. 
     Turning to  FIG. 4 , in STEP  405 , the power supply component  189  provides power to the resources  150 ,  170 ,  175 ,  185  and  190  of the network element  120 . In STEP  410 , the maintenance component  130  makes a determination to operate in the deferred maintenance mode. In STEP  415 , the maintenance component  130  cooperates with the power supply component  189  to determine a level of available power of the power supply component  189 . In STEP  420 , the maintenance component  130  determines to power down redundant and non-essential resources based on the level of available power of the power supply component  189 . Level of power available includes factors like current capacity, cooling, battery life, and fuel level in auxiliary generators. In STEP  425 , the maintenance component  130  cooperates with the power supply component  189  to power down the resource  175  and the resource  195 . The maintenance component  130  repeats STEPS  410  through  425  to re-evaluate the level of available power of the power supply component  189 . The maintenance component  130  cooperates with the power supply component  189  to power down one or more of the resources  150 ,  170 ,  175 ,  185  and  190  of the network element  120  based on the level of available power of the power supply component  189  while operating in the deferred maintenance mode. 
     Turning to  FIG. 5  in another exemplary implementation of the apparatus  100 , a network operations center  505  monitors one or more wirecenters  510 ,  515  and  520  of a network  525 , for example, one or more central offices. The wirecenter  510  (e.g., central office) comprises network elements  550  and  555 . The wirecenter  515  comprises network elements  560 ,  565 , and  570 . The wirecenter  520  comprises network elements  575  and  580 . The network operations center  505  comprises a maintenance component  530  and a recordable data storage medium  535 . The maintenance component  530  is analogous to the maintenance components  125  and/or  130  of  FIG. 1 . The recordable data storage medium  535  is analogous to the recordable data storage mediums  135  and/or  140  of  FIG. 1 . The maintenance component  530  employs the wirecenters  510 ,  515  and  520  to provide at least a subset of functionality for the network  525  when a wirecenter, for example, the wirecenter  510 , of the wirecenters  510 ,  515  and  520  of the network  525  operates in a state of reduced, nonzero functionality. For example, the maintenance component  530  cooperates with the wirecenters  510  and  515  to route traffic across the network  525  when the wirecenter  520  is unavailable, (i.e., the network elements  560 ,  565  and/or  570  are unavailable to route the traffic across the network  525 ). 
     The apparatus  100  in one example comprises a plurality of components such as one or more of electronic components, hardware components, and computer software components. A number of such components can be combined or divided in the apparatus  100 . An exemplary component of the apparatus  100  employs and/or comprises a set and/or series of computer instructions written in or implemented with any of a number of programming languages, as will be appreciated by those skilled in the art. The apparatus  100  in one example comprises any (e.g., horizontal, oblique, or vertical) orientation, with the description and figures herein illustrating one exemplary orientation of the apparatus  100 , for explanatory purposes. 
     The apparatus  100  in one example employs one or more computer-readable signal-bearing media. Examples of a computer-readable signal-bearing medium for the apparatus  100  comprise the recordable data storage mediums  135  and  140  of the network elements  115  and  120 . For example, the computer-readable signal-bearing medium for the apparatus  100  comprises one or more of a magnetic, electrical, optical, biological, and atomic data storage medium. In one example, the computer-readable signal-bearing medium comprises a modulated carrier signal transmitted over a network comprising or coupled with the apparatus  100 , for instance, one or more of a telephone network, a local area network (“LAN”), a wide area network (“WAN”), the internet, and a wireless network. 
     The steps or operations described herein are just exemplary. There may be many variations to these steps or operations without departing from the spirit of the invention. For instance, the steps may be performed in a differing order, or steps may be added, deleted, or modified. 
     Although exemplary implementations of the invention have been depicted and described in detail herein, it will be apparent to those skilled in the relevant art that various modifications, additions, substitutions, and the like can be made without departing from the spirit of the invention and these are therefore considered to be within the scope of the invention as defined in the following claims.