Patent Publication Number: US-2009225672-A1

Title: Methods and apparatus to detect wideband interference in digital subscriber line (dsl) systems

Description:
FIELD OF THE DISCLOSURE 
     This disclosure relates generally to digital subscriber line (DSL) systems and, more particularly, to methods and apparatus to detect wideband interference in DSL systems. 
     BACKGROUND 
     Communication systems using digital subscriber line (DSL) technologies are commonly utilized to provide Internet related services to subscribers, such as, homes and/or businesses (also referred to herein collectively and/or individually as users, customers and/or customer-premises). DSL technologies enable customers to utilize telephone lines (e.g., ordinary twisted-pair copper telephone lines used to provide Plain Old Telephone System (POTS) services) to connect the customer to, for example, a high data-rate broadband Internet network, broadband service and/or broadband content. For example, a communication company and/or service provider may utilize a plurality of modems (e.g., a plurality of DSL modems) implemented by a DSL Access Multiplexer (DSLAM) at a central office (CO) to provide DSL communication services to a plurality of modems located at respective customer-premises. In general, a CO DSL modem receives broadband service content from, for example, a backbone server and forms a digital downstream DSL signal to be transmitted to a customer-premises DSL modem. Likewise, the CO DSL modem receives an upstream DSL signal from the customer-premises DSL modem and provides the data transported in the upstream DSL signal to the backbone server. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic illustration of an example digital subscriber line (DSL) communication system constructed in accordance with the teachings of the invention. 
         FIG. 2  illustrates an example manner of implementing the example DSL diagnostic tool of  FIG. 1 . 
         FIG. 3  illustrates an example manner of implementing the example data analysis module of  FIG. 2 . 
         FIG. 4  is a flowchart representative of example machine accessible instructions that may be carried out by, for example, a processor to implement any or all of the example DSL diagnostic tools of  FIGS. 1  and/or  2 . 
         FIG. 5  is a schematic illustration of an example processor platform that may be used and/or programmed to execute the example machine accessible instructions of  FIG. 4  to implement any or all of the example DSL diagnostic tools described herein. 
     
    
    
     DETAILED DESCRIPTION 
     Methods and apparatus to detect wideband interference in digital subscriber line (DSL) systems are disclosed. A disclosed example method includes retrieving a first plurality of performance parameters for a first time interval for respective ones of a plurality of DSL modems, wherein each the plurality of DSL modems are associated with respective ones of a plurality of subscriber loops, and comparing each of the performance parameters to a threshold to determine whether two or more of the respective ones of the plurality of subscriber loops experienced respective performance degradations during the first time interval. The example method further comprises determining whether the two or more subscriber loops that experienced the respective performance degradations during the first time interval are communicatively coupled to a common serving terminal, and automatically generating a repair ticket when the two or more subscriber loops that experienced the respective performance degradations during the first time interval are served from the common serving terminal, the repair ticket representing a possible wideband noise interference condition affecting more than one of the plurality of subscriber loops. 
     A disclosed example apparatus includes a database interface module to retrieve from a DSL performance database a first plurality of performance parameters for a time interval for respective ones of a plurality of DSL modems, wherein the plurality of DSL modems are associated with respective ones of a plurality of subscriber loops, a data analysis module to determine whether two or more of the respective ones of the plurality of subscriber loops experienced a common performance degradation during the time interval based on the first plurality of performance parameters, and a ticket system interface module to generate a repair ticket when the two or more subscriber loops that experienced the respective performance degradation during the time interval are served from the common serving terminal, the repair ticket identifying the common performance degradation. 
     While methods and apparatus to detect wideband interference in a DSL system are described herein, the example methods and apparatus may, additionally or alternatively, be used to detect other types of interference and/or to detect interference in other types of communication systems. Other example systems include, but are not limited to, those associated with public switched telephone network (PSTN) systems, public land mobile network (PLMN) systems (e.g., cellular), wireless distribution systems, wired or cable distribution systems, coaxial cable distribution systems, Ultra High Frequency (UHF)/Very High Frequency (VHF) radio frequency systems, satellite or other extra-terrestrial systems, cellular distribution systems, power-line broadcast systems, fiber optic networks, passive optical network (PON) systems, and/or any combination and/or hybrid of these devices, systems and/or networks. 
       FIG. 1  illustrates an example DSL communication system in which a central office (CO)  105  provides data and/or communication services (e.g., telephone services, Internet services, data services, messaging services, instant messaging services, electronic mail (email) services, chat services, video services, audio services, gaming services, etc.) to one or more customer premises, three of which are designated at reference numerals  110 ,  111  and  112 . To provide DSL communication services to the customer premises  110 - 112 , the example CO  105  of  FIG. 1  includes any number and/or type(s) of DSL access multiplexers (DSLAMs) (three of which are designated at reference numerals  115 ,  116  and  117 ) and the example customer premises  110 - 112  include any type(s) of customer-premises equipment (CPE) DSL modems  120 ,  121  and  122 . The example DSLAMs  115 - 117  of  FIG. 1  include and/or implement one or more CO DSL modems (not shown) for respective ones of the customer-premises locations  110 - 112 . The example DSLAMs  115 - 117 , the CO DSL modems within the DSLAMs  115 - 117 , and/or the example CPE, such as DSL modems of  FIG. 1  may be implemented, for example, in accordance with the International Telecommunications Union-Telecommunications Sector (ITU-T) G.993.x family of standards for very high-speed DSL (VDSL), and/or the ITU-T G.992.x family of standards for asymmetric DSL (ADSL). 
     In the illustrated example of  FIG. 1 , the DSLAM  115  provides DSL services to the DSL modems  120 - 122  via respective subscriber lines  125 ,  126  and  127 . Subscriber lines are sometimes also referred to in the industry as “wire-pairs”, “subscriber loops” and/or “loops.” While throughout this disclosure reference is made to the example subscriber lines  125 ,  126  and/or  127  of  FIG. 1 , a subscriber line (e.g., any of the example subscriber lines  125 - 127 ) used to provide a DSL service to a customer-premises location (e.g., any of the locations  110 - 112 ) may include and/or be constructed from one or more segments of twisted-pair telephone wire (e.g., a combination of a feeder one (F1) cable, a distribution cable, a drop cable, and/or customer-premises wiring), terminals and/or distributions points (e.g., a serving area interface (SAI), a serving terminal  128 ,  129 , a vault and/or a pedestal). Such segments of twisted-pair telephone wire may be spliced and/or connected end-to-end, and/or may be connected at only one end thereby creating one or more bridged-taps. Regardless of the number, type(s), gauge(s) and/or topology of twisted-pair telephone wires used to construct the example subscriber lines  125 - 127 , they will be referred to herein in the singular form, but it will be understood that the term “subscriber line” may refer to one or more twisted-pair telephone wire segments and may include one or more bridged taps. 
     The example serving terminals  128 ,  129  of  FIG. 1  route, couple and/or connect subscriber lines  125 - 127  to CPE DSL modems  120 - 122  for and/or within a particular geographic area (e.g., a neighborhood and/or a street). For example, the example serving terminal  128  couples a first-wire pair  125  of a distribution cable  123  to the customer premises  110 , and couples a second-wire pair  126  of the distribution cable  123  to the customer premises  111 . In this manner, the example serving terminal  128  implements a wiring distribution point, terminal and/or pedestal. Each of the example CPE DSL modems  120 - 122  of  FIG. 1  are “served” by and/or associated with a particular serving terminal  128 ,  129  that is used to route a subscriber line  125 - 126  to its respective CPE DSL modem  120 - 122 . Because the example customer premises  110  and  111  of  FIG. 1  are served by a common serving terminal  128  and thereby geographically near to each other, the subscriber lines  125  and  126  may be exposed to one or more sources of noise, interference and/or performance degradation. Example common sources that may affect subscriber lines  125 - 127  that are commonly located include, but are not limited to, a AM radio transmitter, a HAM radio transmitter, crosstalk noise with a distribution cable bundle, a defective television and/or a defective digital versatile disc (DVD) player. It has been observed in the field, and experimentally verified, that a defective television and/or DVD player can create radio frequency interference (RFI) that causes dramatic degradations in downstream performance (e.g., from 1.5 Million bits per second (Mb/s) to 448 thousand bits per second (kb/s)) for multiple customer-premises  110 - 112  in the vicinity of a particular serving terminal  128 ,  129 . Such noise sources are wideband in nature and cause interference into a large number (e.g., hundreds) of the sub-carriers available to form a downstream DSL signal, while narrowband noise sources (e.g., a AM radio transmitter) affect fewer sub-carriers (e.g., a few). In many instances, when a defective television is turned on, nearby DSL modems  120 - 122  will experience a burst or errors and/or lose synchronization, retrain and then regain synchronization albeit at a much lower maximum downstream data rate. However, once a defective television or DVD player is identified, the interference can be substantially reduced and/or eliminated by, for example, providing appropriate filtering and/or blocking on coaxial cables, antennas and/or power lines. For instance, by installing a Tripp-Lite isobar surge protector. 
     In traditional DSL communication systems, interference, noise and/or performance problems are diagnosed and/or resolved once a subscriber contacts a customer service and/or technical support line to report a problem for a particular subscriber line. However, such problems must often be resolved without the benefit of information concerning other potentially affected subscriber lines. Such traditional processes can result in decreased customer satisfaction and may be unable to properly correct reported problems when the source of a reported problem is intermittent in nature. 
     In contrast, the methods and apparatus described herein proactively monitor and/or review the aggregate and/or overall performance of all subscriber lines (e.g., the example subscriber lines  125 - 127 ) of a CO (e.g., the example CO  105 ) at periodic or a periodic intervals to detect the intermittent and/or regular occurrence of performance degradations experienced by multiple subscriber lines  125 - 127  of a serving terminal  128 ,  129  due to wideband noise sources, such as a defective television and/or DVD player. Once such wideband noise sources are identified, a trouble and/or repair ticket is automatically generated such that a service technician can identify and/or mitigate the issue, sometimes prior to subscribers being aware and/or reporting that a problem exists. In this way, a service provider can enhance the quality of the DSL services provided via the CO  105  and the subscriber&#39;s perception of the same. 
     To proactively monitor and/or diagnosis a subscriber line (e.g., one of the example subscriber lines  125 - 127 ), the example DSL communication system of  FIG. 1  includes a DSL diagnostic tool  130 . Based on a schedule (e.g., hourly, daily, weekly, etc.) the example DSL diagnostic tool  130  of  FIG. 1  automatically analyzes historical and/or current performance data associated with each of the subscriber lines  125 - 127 , for example, is collected from the example DSLAMs  115 - 117  by an access management system (AMS) server  135  and stored in a performance database  140 . In some instances the performance data analyzed are aggregate performance data and/or aggregate performance parameters that reflect the overall operating condition of each of the subscriber lines  125 - 127 . Using the aggregate performance data obtained from the DSL performance database  140  (e.g., maximum attainable downstream data rates, and/or error rates and/or counters), the example DSL diagnostic tool  130  attempts to identify whether a serving terminal  128 ,  129  is affected by a wideband noise and/or interference source that is affecting multiple subscriber lines  125 - 127  associated with the serving terminal  128 ,  129 . The example DSL diagnostic tool  130  correlates the time(s) and/or time interval(s) at which subscriber lines  125 - 127  of a particular serving terminal  128 ,  129  are and/or have experienced significant degradations in performance (e.g., a fifty percent decrease in maximum attainable downstream data rate or a marked increase in errors). Two or more subscriber lines  125 - 127  of a serving terminal  128 ,  129  experiencing significant performance degradations during the same time interval(s) and/or at the same time(s) is indicative of a wideband noise source, such as a defective television or DVD player. When such a wideband noise and/or interference source is detected, the example DSL diagnostic tool  130  of  FIG. 1  automatically generates and/or submits a repair ticket to a trouble ticket system  145  so that an appropriate technician can be dispatched to locate, mitigate and/or resolve the problem (e.g., identify a faulty television and install an isolating surge protector). An example manner of implementing the example DSL diagnostic tool  130  of  FIG. 1  is described below in connection with  FIGS. 2  and/or  4 . 
     To collect performance data, the example CO  105  of  FIG. 1  includes the example AMS server  135 . The example AMS server  135  of  FIG. 1  periodically or aperiodically collects performance data (e.g., maximum attainable data rates, error counters, estimated loop lengths, DSL connection rates, loop attenuation values, error rates, signal-to-noise ratios, bit allocations, noise margins, DSL modem configurations, etc.) from the example DSLAMs  115 - 117  and/or customer-premises DSL modems  120 ,  121  communicatively coupled to the DSLAMs  115 - 117 . 
     To manage repair and/or maintenance reports, the example CO  105  of  FIG. 1  includes the example trouble ticket system  145 . The example trouble ticket system  145  of  FIG. 1  implements an application programming interface (API) via which the example DSL diagnostic tool  130  can submit a trouble ticket. The example trouble ticket system  145  also routes a submitted trouble ticket to a suitable repair, customer support and/or technical support person for resolution, and tracks the resolution of trouble tickets. 
     While in the illustrated example of  FIG. 1 , the example DSLAMs  115 - 117 , the example DSL diagnostic tool  130 , the example AMS server  135 , the example DSL performance database  140 , and the example trouble ticket system  145  are illustrated in connection with the example CO  105 , one or more of the DSL diagnostic tool  130 , the example AMS server  135 , the example DSL performance database  140 , and/or the example trouble ticket system  145  may be located and/or implemented separately from the CO  105 . For example, the DSL diagnostic tool  130 , the example DSL performance database  140 , and/or the example trouble ticket system  145  may be located and/or implemented at a customer service location (not shown), which is communicatively coupled to the AMS  135  at the CO  105 . Further any number of DSLAMs  115 - 117  may be implemented and/or located at a CO. Moreover, a DSLAM  115 - 117  may be implemented and/or located at a remote terminal (not shown), which is communicatively coupled to the example DSL diagnostic tool  130  via an AMS server (e.g., the example AMS server  135  at a CO (e.g., the example CO  105 ). 
       FIG. 2  illustrates an example manner of implementing the example DSL diagnostic tool  130  of  FIG. 1 . To interact with the example performance database  140 , the example DSL diagnostic tool  130  of  FIG. 2  includes a database interface module  205 . The example database interface module  205  of  FIG. 2  implements one or more APIs to allow other elements of the example DSL diagnostic tool  130  to perform queries of the example performance database  140  to, for example, obtain performance data associated with a subscriber loop. 
     To interact with the example trouble ticket system  145 , the example DSL diagnostic tool  130  of  FIG. 2  includes a trouble ticket submitter  210 . The example trouble ticket submitter  210  of  FIG. 2  submits repair tickets for serving terminals and/or subscriber lines identified by a data analysis module  215 . The example trouble ticket submitter  210  submits a trouble ticket by, for example, accessing and/or utilizing an API provided and/or implemented by the example trouble ticket system  145 . In some examples, the trouble ticket submitter  210  includes diagnostic data (e.g., which subscriber lines are affected, time(s) of day when the subscriber lines were affected by wideband noise, etc.) as part of a submitted trouble ticket. Such included information may be used by, for example, a repair technician while diagnosing a detected problem. 
     To analyze performance data, the example DSL diagnostic tool  130  of  FIG. 2  includes a data analysis module  215  and a scheduler  220 . The example scheduler  220  of  FIG. 1  directs the example data analysis module  215  to periodically or aperiodically analyzes historical and/or current performance data stored in the DSL performance database  140 . The times set by the scheduler  220  may be programmed by a technician. 
     Using the performance data obtained from the DSL performance database  140  (e.g., maximum attainable downstream data rates, error rates and/or error counters), the example data analysis module  215  of  FIG. 2  attempts to proactively identify whether a serving terminal is affected by a wideband noise and/or interference source that is affecting multiple subscriber lines associated with the serving terminal. The example data analysis module  215  correlates the time(s) and/or time interval(s) at which subscriber lines of a particular serving terminal are and/or have experienced significant degradations in performance (e.g., a fifty percent decrease in maximum attainable downstream data rate or a marked increased in errors). When such a wideband noise and/or interference source is detected, the example data analysis module  215  notifies the example trouble ticket submitter  210  of the occurrence. The trouble ticket submitter  220  responds by automatically submitting a repair ticket to the trouble ticket system  145  so that an appropriate technician can be dispatched to locate, mitigate and/or resolve the problem (e.g., identify a faulty television and install an isolating surge protector). An example manner of implementing the example data analysis module  215  of  FIG. 2  is described below in connection with  FIG. 3 . 
     While an example manner of implementing the example DSL diagnostic tool  130  of  FIG. 1  has been illustrated in  FIG. 2 , one or more of the elements, processes and/or devices illustrated in  FIG. 2  may be combined, divided, re-arranged, omitted, eliminated and/or implemented in any other way. Further, the example database interface module  205 , the example trouble ticket submitter  210 , the example data analysis module  215 , the example scheduler  220  and/or, more generally, the example DSL diagnostic tool  130  of  FIG. 2  may be implemented by hardware, software, firmware and/or any combination of hardware, software and/or firmware. Thus, for example, any or the example database interface module  205 , the example trouble ticket submitter  210 , the example data analysis module  215 , the example scheduler  220  and/or, more generally, the example DSL diagnostic tool  130  may be implemented by one or more circuit(s), programmable processor(s), application specific integrated circuit(s) (ASIC(s)), programmable logic device(s) (PLD(s)) and/or field programmable logic device(s) (FPLD(s)), etc. When any of the appended claims are read to cover a purely software implementation, at least one of the example database interface module  205 , the example trouble ticket submitter  210 , the example data analysis module  215 , the example scheduler  220  and/or, more generally, the example DSL diagnostic tool  130  are hereby expressly defined to include a tangible medium such as a memory, a DVD, a compact disc (CD), etc. Further still, the example DSL diagnostic tool  130  may include one or more elements, processes and/or devices in addition to, or instead of, those illustrated in  FIG. 2 , and/or may include more than one of any or all of the illustrated elements, processes and devices. 
       FIG. 3  illustrates an example manner of implementing the example data analysis module  215  of  FIG. 2 . To identify degraded subscriber lines (e.g., any of the example subscriber lines  125 - 127  of  FIG. 1 ), the example data analysis module  215  of  FIG. 3  includes a line performance analyzer  305 . The example line performance analyzer  305  of  FIG. 3  processes a performance data record (e.g., containing a plurality of maximum attainable data rates for respective ones of a plurality of time intervals and/or instants) for each subscriber line of a CO to create a list of potential times and/or time intervals when a serving terminal may have been affected by a wideband noise and/or interference source. 
     To identify affected serving terminals, the example data analysis module  215  of  FIG. 3  includes a serving terminal analyzer  310 . The example serving terminal analyzer  310  of  FIG. 3  processes the list created by the example line performance analyzer  305  to determine whether two or more subscriber lines of a serving terminal experienced significant performance degradation during the same time interval(s) and/or at the same time instant(s). For such affected serving terminals, the example serving terminal analyzer  310  (a) compiles a tabulation of the affected subscriber lines and the times at which the subscriber lines experienced degraded performance, and (b) notifies the example trouble ticket submitter  210  of  FIG. 2  of the occurrence(s) and identifies the affected serving terminal(s). 
     While an example manner of implementing the example data analysis module  215  of  FIG. 2  has been illustrated in  FIG. 3 , one or more of the elements, processes and/or devices illustrated in  FIG. 3  may be combined, divided, re-arranged, omitted, eliminated and/or implemented in any other way. Further, the example line performance analyzer  305 , the example serving terminal analyzer  310  and/or, more generally, the example data analysis module  215  of  FIG. 3  may be implemented by hardware, software, firmware and/or any combination of hardware, software and/or firmware. Thus, for example, any or the example line performance analyzer  305 , the example serving terminal analyzer  310  and/or, more generally, the example data analysis module  215  may be implemented by one or more circuit(s), programmable processor(s), ASIC(s), PLD(s) and/or FPLD(s), etc. When any of the appended claims are read to cover a purely software implementation, at least one of the example line performance analyzer  305 , the example serving terminal analyzer  310  and/or, more generally, the example data analysis module  215  are hereby expressly defined to include a tangible medium such as a memory, a DVD, a CD, etc. Further still, the example analysis module  215  of  FIG. 3  may include one or more elements, processes and/or devices in addition to, or instead of, those illustrated in  FIG. 3 , and/or may include more than one of any or all of the illustrated elements, processes and devices. 
       FIG. 4  is a flowchart representative of example machine accessible instructions that may be carried out to implement any or all of the example DSL diagnostic tools  130  of  FIGS. 1  and/or  2 . The example machine accessible instructions of  FIG. 4  may be carried out by a processor, a controller and/or any other suitable processing device. For example, the example machine accessible instructions of  FIG. 8  may be embodied in coded instructions stored on a tangible medium such as a flash memory, a read-only memory (ROM) and/or random-access memory (RAM) associated with a processor (e.g., the example processor  9005  discussed below in connection with  FIG. 5 ). Alternatively, some or all of the example machine accessible instructions of  FIG. 4  may be implemented using any combination(s) of circuit(s), ASIC(s), PLD(s), FPLD(s), discrete logic, hardware, firmware, etc. Also, some or all of the example machine accessible instructions of  FIG. 4  may be implemented manually or as any combination of any of the foregoing techniques, for example, any combination of firmware, software, discrete logic and/or hardware. Further, although the example operations of  FIG. 4  are described with reference to the flowchart of  FIG. 4 , many other methods of implementing the operations of  FIG. 4  may be employed. For example, the order of execution of the blocks may be changed, and/or one or more of the blocks described may be changed, eliminated, sub-divided, or combined. Additionally, any or all of the example machine accessible instructions of  FIG. 4  may be carried out sequentially and/or carried out in parallel by, for example, separate processing threads, processors, devices, discrete logic, circuits, etc. 
     The example machine accessible instructions of  FIG. 4  begin when the example scheduler  220  of  FIG. 2  directs the example DSL diagnostic  130  tool to process performance data to identify potential wideband interference in a DSL system. The example data interface module  205  queries the example DSL performance database  140  to obtain the address of a serving terminal associated with a particular subscriber line (e.g., any of the example subscriber lines  125 - 127 ) (block  405 ). The data interface module  205  obtains the first performance parameter (e.g., maximum attainable data rate) corresponding to a first time interval and/or instant from a performance data record for the given subscriber line (block  410 ). 
     The example line performance analyzer  305  of  FIG. 3  determines whether the first performance parameter indicates that performance was significantly degraded (e.g., a fifty percent drop in maximum attainable data rate) compared to a previous time instant (e.g., a week ago) (block  415 ). If a significant performance degradation occurred (block  415 ), the line performance analyzer  305  adds an entry to a hash table containing a timestamp corresponding to the first time interval and the serving terminal address (block  420 ). If a significant performance degradation did not occur (block  415 ), control proceeds to block  425  without adding an entry to the hash table. If there are more performance parameters in the performance data record for the given subscriber loop (block  425 ), control returns to block  410  to process the next performance data entry. 
     If all of the performance data for the given subscriber loop has been processed (block  425 ), the line performance analyzer  305  determines if the performance data for all subscriber loops has been processed (block  430 ). If all subscriber loops have not been processed (block  430 ), control returns to block  405  to process the next subscriber loop. 
     If all subscriber loops have been processed (block  430 ), the example serving terminal analyzer  310  of  FIG. 3  processes the hash table to identify a list of affected serving terminals (i.e., those serving terminals having two or more subscriber loops affected during the same time instant) (block  435 ). For each affected serving terminal, the serving terminal analyzer  310  creates a list of the affected subscriber loops for each time instant and/or interval where wideband noise was detected (block  440 ). 
     The serving terminal analyzer  310  sorts the list of affected serving terminals based on the extent (e.g., number of affected subscriber loops, number of affected time intervals, etc.) (block  445 ). The example trouble ticket submitter  210  of  FIG. 2  then submits trouble tickets for the affected serving terminals (block  450 ). In some examples, the trouble ticket submitter  210  only automatically submits trouble tickets for severely affected serving terminals (e.g., those terminals in which more than  20 % of subscriber loops are affected). Control then exits from the example machine accessible instructions of  FIG. 4 . 
       FIG. 5  is a schematic diagram of an example processor platform  9000  that may be used and/or programmed to implement all or a portion of any or all of the example DSL diagnostic tool  130 , the example database interface module  205 , the example trouble ticket submitter  210 , the example data analysis module  215 , the example scheduler  220 , the example line performance analyzer  305 , and/or the example serving terminal analyzer  310  of  FIGS. 1 ,  2 , and/or  3 . For example, the processor platform  9000  can be implemented by one or more general purpose processors, processor cores, microcontrollers, etc. 
     The processor platform  9000  of the example of  FIG. 5  includes at least one general purpose programmable processor  9005 . The processor  9005  executes coded instructions  9010  and/or  9012  present in main memory of the processor  9005  (e.g., within a RAM  9015  and/or a ROM  9020 ). The processor  9005  may be any type of processing unit, such as a processor core, a processor and/or a microcontroller. The processor  9005  may execute, among other things, the example machine accessible instructions of  FIG. 4  to implement the example methods and apparatus described herein. 
     The processor  9005  is in communication with the main memory (including a ROM  9020  and/or the RAM  9015 ) via a bus  9025 . The RAM  9015  may be implemented by DRAM, SDRAM, and/or any other type of RAM device, and ROM may be implemented by flash memory and/or any other desired type of memory device. Access to the memory  9015  and the memory  9020  may be controlled by a memory controller (not shown). One or both of the example memories  9015  and  9020  may be used to implement the example DSL performance database  140  of  FIG. 1 . 
     The processor platform  9000  also includes an interface circuit  9030 . The interface circuit  9030  may be implemented by any type of interface standard, such as an external memory interface, serial port, general purpose input/output, etc. One or more input devices  9035  and one or more output devices  9040  are connected to the interface circuit  9030 . The input devices  9035  and/or output devices  9040  may be used to, for example, implement the example database interface module  205  and/or the example trouble ticket submitter  210  of  FIG. 2 . 
     Of course, the order, size, and proportions of the memory illustrated in the example systems may vary. Additionally, although this patent discloses example systems including, among other components, software or firmware executed on hardware, such systems are merely illustrative and should not be considered as limiting. For example, it is contemplated that any or all of these hardware and software components could be embodied exclusively in hardware, exclusively in software, exclusively in firmware or in some combination of hardware, firmware and/or software. Accordingly, the above described examples are not the only way to implement such systems. 
     At least some of the above described example methods and/or apparatus are implemented by one or more software and/or firmware programs running on a computer processor. However, dedicated hardware implementations including, but not limited to, an ASIC, programmable logic arrays and other hardware devices can likewise be constructed to implement some or all of the example methods and/or apparatus described herein, either in whole or in part. Furthermore, alternative software implementations including, but not limited to, distributed processing or component/object distributed processing, parallel processing, or virtual machine processing can also be constructed to implement the example methods and/or apparatus described herein. 
     It should also be noted that the example software and/or firmware implementations described herein are optionally stored on a tangible storage medium, such as: a magnetic medium (e.g., a disk or tape); a magneto-optical or optical medium such as a disk; or a solid state medium such as a memory card or other package that houses one or more read-only (non-volatile) memories, random access memories, or other re-writable (volatile) memories; or a signal containing computer instructions. A digital file attachment to e-mail or other self-contained information archive or set of archives is considered a distribution medium equivalent to a tangible storage medium. Accordingly, the example software and/or firmware described herein can be stored on a tangible storage medium or distribution medium such as those described above or equivalents and successor media. 
     To the extent the above specification describes example components and functions with reference to particular devices, standards and/or protocols, it is understood that the teachings of the invention are not limited to such devices, standards and/or protocols. Such systems are periodically superseded by faster or more efficient systems having the same general purpose. Accordingly, replacement devices, standards and/or protocols having the same general functions are equivalents which are intended to be included within the scope of the accompanying claims. 
     Although certain example methods, apparatus and articles of manufacture have been described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.