WO1999050986A1 - System and method for trafficking telecommunication signals - Google Patents
System and method for trafficking telecommunication signals Download PDFInfo
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- WO1999050986A1 WO1999050986A1 PCT/US1999/007166 US9907166W WO9950986A1 WO 1999050986 A1 WO1999050986 A1 WO 1999050986A1 US 9907166 W US9907166 W US 9907166W WO 9950986 A1 WO9950986 A1 WO 9950986A1
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/16—Time-division multiplex systems in which the time allocation to individual channels within a transmission cycle is variable, e.g. to accommodate varying complexity of signals, to vary number of channels transmitted
- H04J3/1605—Fixed allocated frame structures
- H04J3/1611—Synchronous digital hierarchy [SDH] or SONET
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/02—Details
- H04J3/14—Monitoring arrangements
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/16—Time-division multiplex systems in which the time allocation to individual channels within a transmission cycle is variable, e.g. to accommodate varying complexity of signals, to vary number of channels transmitted
- H04J3/1605—Fixed allocated frame structures
- H04J3/1623—Plesiochronous digital hierarchy [PDH]
- H04J3/1635—Format conversion, e.g. CEPT/US
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S370/00—Multiplex communications
- Y10S370/901—Wide area network
- Y10S370/902—Packet switching
- Y10S370/903—Osi compliant network
- Y10S370/907—Synchronous optical network, SONET
Definitions
- This invention relates generally to the field of communications and more particularly to a system and method of trafficking telecommunication signals having different formats .
- Telecommunication networks in North America generally support the Synchronous Optical Network (“SONET”) format.
- Telecommunication networks in various other parts of the world, such as Europe, typically support the Synchronous Digital Hierarchy (“SDH”) format.
- SONET Synchronous Optical Network
- SDH Synchronous Digital Hierarchy
- traffic or “trafficking” refer generally to the transmission, reception, switching, mapping, performance monitoring and various other functions relating to management of telecommunication signals.
- Transitioning from a SONET network to an SDH network generally requires terminating the SONET-based synchronous path and associated overhead portions of the SONET-based signal, extracting a desired asynchronous payload, remapping the payload into an SDH-based signal, and reconstructing the synchronous path and associated overhead portions according to SDH standards. Transitioning from an SDH network to a SONET network typically involves similar steps of path termination, embedded signal extraction, signal remapping, and reconstruction of synchronous path and associated overhead according to SONET standards.
- Terminating the synchronous path and associated overhead portion increases the cost of the equipment by introducing additional ports necessary to handle the lower-level embedded signals after path termination. Terminating synchronous path and associated overhead also increases the probability of signal integrity loss during the transition from one format to the other. Each time the synchronous path and associated overhead is terminated and reconstructed, there is an additional potential for introducing error.
- a system and method for trafficking telecommunication signals having different formats is provided that substantially eliminate or reduce disadvantages or problems associated with previously developed systems and methods.
- the present invention facilitates trafficking telecommunication signals having a first format over a network supporting a second format, without terminating the synchronous path or associated overhead portions of each signal .
- a method of trafficking telecommunication signals having various formats comprises providing, at a first network element, a synchronous payload envelope having a first format, the synchronous payload envelope comprising a synchronous path and associated overhead portion and a payload portion, mapping the synchronous payload envelope into a transport signal having a second format without terminating the synchronous path or associated overhead portions of the synchronous payload envelope, and transmitting the transport signal to a second network element over a network supporting the second format .
- Technical advantages of the present invention include the provision of a method and apparatus for trafficking telecommunication signals having a first format over a network supporting a second format without terminating the synchronous path or associated overhead portions of each signal.
- Cross connecting signals having different formats without terminating the synchronous path or associated overhead portions of the signals provides an advantage of facilitating inexpensive switching across SONET and SDH networks while preserving the ability to monitor the performance of the signals being switched. Eliminating the need to terminate synchronous path and associated overhead portions of the signal saves equipment cost by eliminating the need for ports to terminate embedded signals. Avoiding termination of the synchronous path and associated overhead portion also aids to ensure signal integrity by leaving the synchronous path and associated overhead portion intact. Other technical advantages are readily apparent to one of skill in the art from the attached figures, description, and claims .
- FIGURE 1 is a block diagram of a system for trafficking telecommunication signals constructed according to the teachings of the present invention
- FIGURE 2 is a block diagram illustrating a mapping of telecommunication signals according to the teachings of the present invention
- FIGURE 3 is a block diagram of a performance monitoring unit constructed according to the teachings of the present invention.
- FIGURES 4a-4b are flow charts illustrating exemplary methods of monitoring the performance of telecommunication signals according to the teachings of the present invention .
- FIGURE 1 is a block diagram of a system for trafficking telecommunication signals constructed according to the teachings of the present invention.
- the terms “traffic” or “trafficking” broadly refer to transmission, reception, switching, mapping, performance monitoring and various other functions relating to management of telecommunication signals.
- System 10 includes a first network element 12 coupled to a second network element 112.
- the term “coupled” denotes either direct, or indirect communication between two or more elements by any appropriate coupling arrangement.
- the term “coupled” does not necessarily denote a physical connection; it is broad enough to encompass any wireline, wireless, electrical, optical or other suitable method of communication between two or more elements.
- first network element 12 is coupled to second network element 112 through a network 14.
- Each of first and second network elements 12 and 112 may couple to additional network elements (not explicitly shown) through one or more additional networks, such as networks 16 and 116, respectively.
- network elements 12 and 112 may couple to additional network elements (not explicitly shown) within networks 14, 16, and 116.
- Networks 14, 16, and 116 may comprise any suitable wireline or wireless system, or combination thereof, that supports communication between various network elements .
- each of networks 14, 16, and 116 may be a public switched telephone network (PSTN) , an integrated services digital network (ISDN) , a local area network (LAN) , a wide area network (WAN) , a global computer network such as the Internet or other dedicated switched network, or other communication system at one or more locations .
- PSTN public switched telephone network
- ISDN integrated services digital network
- LAN local area network
- WAN wide area network
- System 10 may comprise any one or a combination of such types of networks .
- network 14 comprises a synchronous digital hierarchy (SDH) network.
- Network 14 may couple first network element 12 located, for example, in New York, U.S.A., to second network element 112 located, for example, in Paris, France.
- network 16 comprises a synchronous optical network (SONET) .
- SONET synchronous optical network
- Network 16 may couple first network element 12 located, for example, in New York, U.S.A., to another network element (not explicitly shown) located, for example, in Los
- network 116 may couple second network element 112 to another network element (not explicitly shown) located, for example, in London, England.
- Network elements 12 and 112 may comprise, for example, cross connects operable to receive telecommunication signals having different formats, and to switch the contents of those signals without terminating the synchronous path or associated overhead portions of the signals.
- telecommunication signal is specifically intended to encompass signals having payloads capable of carrying voice, video, and/or various forms of data.
- each of network elements 12 and 112 is capable of receiving and processing signals having a SONET format and signals having an SDH format. As discussed in detail below, the manner in which network elements 12 and 112 deal with each signal depends on the format of the particular signal.
- Cross connecting signals having different formats without terminating the synchronous path or associated overhead portions of the signals provides an advantage of facilitating inexpensive switching across SONET and SDH networks while preserving the ability to monitor the performance of the signals being switched. Details of the performance monitoring characteristics of system 10 will be described below.
- Network elements 12 and 112 are similar in structure and function. For clarity and simplicity of description, the following description of these network elements will be limited a discussion of network element 12. It should be understood that network element 112 includes similar components and functionality.
- Network element 12 includes synchronous payload envelope (SPE) decoders 18 and 20, which are operable to receive incoming synchronous transport signals 22 and 24 from networks 14 and 16, respectively.
- incoming synchronous transport signal 22 comprises an SDH- based transport signal.
- SDH-based transport signal 22 may comprise, for example, a Synchronous Transport Module level-4 (STM-4) signal; however, other types of SDH-based transport signals can likewise be processed.
- Synchronous transport signal 24 comprises a SONET-based transport signal.
- SONET-based transport signal 24 may comprise, for example, an Optical Carrier level-12 (OC-12) signal, although other types of SONET-based transport signals can be processed in accordance with the teachings of the present invention.
- OC-12 Optical Carrier level-12
- SPE decoders 18 and 20 are operable to receive and process incoming transport signals 22 and 24 by, for example, terminating the transport overhead associated with these signals, and extracting synchronous payload envelopes (SPE) 26 and 28, respectively therefrom.
- SPE 26 comprises an SDH-based virtual container level-3 (VC-3)
- SPE 28 comprises a SONET-based synchronous transport signal level one synchronous payload envelope (STS-1 SPE) .
- SPE decoders may comprise path termination components (not explicitly shown) operable to terminate the synchronous path and associated overhead portions of the SPEs received, and to extract component signals carried by the SPEs.
- Performance monitoring units 30 and 32 are coupled to SPE decoders 18 and 20, respectively. As will be discussed in detail below, performance monitoring units 30 and 32 are operable to identify the format of each signal received, and to provide signal monitoring functionality, such as path tracing and error detection, in accordance with standards associated with the format of each signal. For example, if performance monitoring unit 30 or 32 concludes that a particular SPE follows the SONET format, performance monitoring functions will be implemented according to standards associated with the SONET format. Likewise, if performance monitoring unit 30 or 32 concludes that a particular SPE follows the SDH format, performance monitoring functions will be implemented according to standards associated with the SDH format. Although the illustrated embodiment shows SPE decoders 18 and 20 and performance monitoring units 30 and 32 as separate components, these entities could be combined into a lesser number of components .
- Network element 12 further includes a matrix 34.
- Matrix 34 receives SPEs 26 and 28 from SPE decoders 18 and 20, respectively.
- Matrix 34 operates to map SPEs 26 and 28 into outgoing synchronous transport signals 36 and 38.
- outgoing synchronous transport signal 36 comprises an SDH-based transport signal
- outgoing synchronous transport signal 38 comprises a SONET-based transport signal.
- Outgoing SDH-based transport signal 36 may comprise, for example, an STM-4 signal.
- Outgoing SONET-based transport signal 38 may comprise, for example, an OC-12 signal.
- other types of SDH and SONET-based signals can be processed in accordance with the teachings of the present invention.
- Matrix 34 is operable to map SONET-based SPEs into SONET-based transport signals or SDH-based transport signals. Similarly, matrix 34 can map SDH-based SPEs into SDH-based transport signals or SONET-based transport signals. In each of these cases, matrix 34 accomplishes its mapping function without terminating the synchronous path or associated overhead portions of the SPEs. This provides significant advantages in reducing system cost and ensuring signal integrity. Additional details of the function of matrix 34 will be explained later in this description.
- system 10 receives a plurality of synchronous transport signals 22, 24, 122, and 124 and cross-connects the signals without terminating the synchronous path or associated overhead portions of the signals.
- a telecommunication signal originating in Los Angeles, California and terminate the signal in Paris, France.
- the information desired to be transmitted from Los Angeles to Paris resides within in a digital signal, level-3 (DS-3) .
- a network element located in Los Angeles, California first maps the DS-3 signal into a SONET-based transport signal 24, in this case an OC-12 signal that is transmitted over network 16 and received at first network element 12, located in New York, New York.
- SPE decoder 20 receives SONET-based transport signal 24 and extracts SONET-based SPE 28 containing an asynchronously mapped DS-3.
- SONET-based SPE comprises an STS-1 SPE containing the asynchronously mapped DS-3.
- Performance monitor unit 32 is operable to receive SONET- based SPE 28, identify its format, and perform signal monitoring functions, such as path tracing and error detection, according to standards associated with the format (SONET) of SPE 28.
- Performance monitoring unit 32 can be operable to report results of the monitoring functions to a network element manager (not explicitly shown) , or to transmit these results to other network elements to facilitate full-network performance monitoring. Additional details of the structure and function of performance monitoring unit 32 will be described later in this document.
- Matrix 34 receives SONET-based SPE 28 from SPE decoder 20, and maps SONET-based SPE 28 into SDH-based transport signal 36 without terminating the synchronous path and associated overhead portion of SONET-based SPE 28, as discussed further in connection with FIGURE 2. Once SONET- based SPE 28 has been mapped into SDH-based transport signal 36, first network element 12 transmits SDH-based transport signal 36 over network 14 to second network element 112, which is located in Paris, France in this example .
- SDH-based transport signal 36 may pass through an appropriate number 10
- SDH-based transport signal 122 represents the transport element containing the desired path after it has been transmitted through network 14.
- SDH-based transport signal 122 comprises SONET-based SPE 28, and may or may not include other SPEs originally contained in SDH-based transport signal 36.
- SPE decoder 118 of second network element 112 receives SDH-based transport signal 122 and extracts each SPE 126 therefrom. Among the SPEs 126 extracted from SDH-based transport signal 122 is SONET-based SPE 28. SPE decoder 118 can then be operable to either terminate the synchronous path and associated overhead portions of SONET- based SPE 28 and extract the DS-3 signals contained therein, or pass SONET-based SPE 28 to cross connect 134 for cross-connection and inclusion within an outgoing transport signal 136 or 138.
- Performance monitoring unit 130 identifies the format of SONET-based SPE 28, and performs various monitoring activities, such as path tracing and error detection, according to standards associated with the format (SONET) of SPE 28. Again, details of the structure and operation of performance monitoring unit 130 will be described later in this document.
- System 10 may also transport SDH-based SPEs within a SONET-based transport signal. For example, it may be desirable to have a second network element 112 receive from SDH network 14 an SDH-based transport signal 122 containing SDH-based SPE 126. It may also be desirable to transmit 11
- SDH-based SPE 126 information contained in SDH-based SPE 126 to a network element in Los Angeles, California (not explicitly shown) .
- matrix 134 of second network element 112 would be operable to receive SDH-based SPE 126 and map it into SDH-based transport signal 136 for transport across SDH network 14 to first network element 12 in New York. Such a mapping process is described below in connection with FIGURE 2.
- SDH-based transport signal 136 emerges in New York from SDH network 14 as SDH-based transport signal 22.
- First network element 12 receives SDH-based transport signal 22 at SPE decoder 18.
- SPE decoder 18 extracts SDH- based SPE 126 from SDH-based transport signal 22, and passes SDH-based SPE 126 to performance monitoring unit 30.
- Performance monitoring unit 30 identifies the format (SDH) of SDH-based SPE 126, for example based on characteristics of the overhead portion of the signal, and performs various monitoring functions in accordance with standards associated with the SDH format.
- SPE decoder 18 also passes SDH-based SPE 128 along with other SPEs 26 to matrix 34.
- Matrix 34 proceeds to map SDH-based SPE 128 into SONET-based transport signal 38, without terminating the synchronous path or associated overhead portion of SDH-based SPE 128.
- first network element 12 After mapping SDH- based SPE 128 into SONET-based transport signal 38, first network element 12 transmits SONET-based transport signal 38 over SONET network 16 to a network element (not explicitly shown) in Los Angeles, California.
- the network element (not explicitly shown) in Los Angeles can be similar in structure and function to first and second network elements 12 and 112. As previously described, the network element in Los Angeles receives the SONET-based transport signal, extracts SDH-based SPE 128, identifies the format (SDH) of SDH-based SPE 128, and provides performance monitoring functions for SDH-based SPE 126 according to standards associated with the SDH format. 12
- the network element in Los Angeles may then terminate SDH- based SPE 128 and extract DS-3 signals contained therein.
- FIGURE 2 is a block diagram illustrating an exemplary mapping of telecommunication signals according to the teachings of the present invention.
- FIGURE 2 shows a series of signals involved in a mapping of a DS-3 signal into a SONET-based OC-12 signal, and for a mapping of DS-3 signal into an SDH-based STM-4 signal.
- the mapping described with reference to FIGURE 2 is for exemplary purposes only. The invention is not intended to be limited to mapping DS-3 signals into STS-1 and STM-4 signals. It is to be appreciated that the teachings of the present invention are also applicable to the mapping of other component signals into various levels of transmission signals.
- a DS-3 signal is mapped, for example, into an OC-12 signal by first mapping the DS-3 signal into an STS-1 synchronous payload envelope 210.
- STS-1 SPE 210 includes a payload portion 212 and a synchronous path and associated overhead portion 214.
- Synchronous path and associated overhead portion 214 comprises information describing, for example, the contents and origination point of the synchronous payload portion of the signal.
- synchronous path and associated overhead portion 214 can comprise a Jl byte including information useful in performing a path trace performance monitoring function, as well as a B3 byte containing information useful in detecting errors in the signal.
- Each STS-1 SPE 210 is mapped into a synchronous transport signal level one (STS-1) 216.
- STS-1 signal 216 includes STS-1 SPE 210, along with transport overhead 218. Twelve STS-1 signals can be multiplexed together to form an electrical synchronous transport signal level-12 (STS-12) . Finally, the electrical STS-12 signal can be converted to an optical 13
- OC-12 signal 250 by appropriate processing that is well established in the telecommunications industry.
- a DS-3 signal is initially mapped into a virtual container level-3 SPE (VC-3) 310.
- Each VC-3 310 includes a payload portion 312 and a synchronous path and associated overhead portion 314.
- VC-3 SPEs in the SDH domain are analogous to STS-1 SPEs in the SONET domain.
- Each carries a substantially similar payload capacity and includes a synchronous path and associated overhead portion.
- the content and interpretation of information contained in the synchronous path and associated overhead portion of each signal varies according to each signal's format.
- synchronous path and associated overhead portion 314 of VC-3 310 comprises information useful in facilitating performance monitoring. The format and interpretation of this information, however, is dictated by standards associated with the SDH domain, which in some cases differ from the standards associated with the SONET domain.
- each VC-3 310 is initially mapped into a TU-3 signal 316.
- Each TU-3 signal 316 comprises VC-3 310 with a transmission overhead pointer 318 appended thereto.
- Each TU-3 signal 316 is mapped into a TUG-3 signal 320, which comprises VC-3 signal 310, transmission path pointer 318, and additional transmission overhead information 322 appended thereto.
- Three TUG-3s can be combined to form a Virtual Container level-4 (VC-4).
- Four VC-4 signals can be combined to form a Synchronous Transport Module level-4 (STM-4) signal 350.
- SDH-based STM-4 signal 350 carries a substantially similar payload as SONET-based OC-12 signal 250.
- Matrix 34 receives synchronous payload envelopes 26 and 28, some having the SDH format, and others 14
- Matrix 34 is operable to map SONET-based SPEs into SONET-based transport signals according to standards associated with the SONET format, such as Bellcore standard GR-253-CORE. Similarly, matrix 34 is operable to map SDH-based SPEs into SDH-based transport signals according to standards associated with the SDH format, such as ITU-T standard G.707.
- matrix 34 is operable to map SONET-based SPEs into SDH-based transport signals, and SDH-based SPEs into SONET-based transport signals, without terminating the synchronous path or associated overhead portions of the SPEs. Matrix 34 accomplishes this direct cross-format mapping by mapping SONET-based SPEs as if they were SDH- based SPEs, and mapping SDH-based SPEs as if they were SONET-based SPEs.
- STS-1 SPE 210 For example, assume it is desired that a particular DS-3 signal presently contained in STS-1 SPE 210 be transmitted over SDH network 14 via STM-4 signal 350.
- the present invention avoids having to terminate the synchronous path and associated overhead portion 214 of STS-1 SPE 210 by mapping STS-1 SPE 210 directly into TU-3 316 as if it were a VC-3 signal. That is, matrix 34 maps STS-1 SPE 210 directly into TU-3 signal 316 according to SDH standards for mapping a VC-3 signal into a TU-3 signal. Matrix 34 accomplishes this mapping without terminating synchronous path and associated overhead portion 214 of STS-1 SPE 210.
- Cross connect 314 continues the mapping process according to the SDH standard and ultimately forms STM-4 signal 350, which contains the desired DS-3 signal within STS-1 SPE signal 210.
- VC-3 signal 310 may be directly mapped into OC-12 signal 250.
- matrix 34 processes VC-3 signal 310 as if it were an STS-1 SPE 15
- Matrix 34 continues the mapping process according to SONET standards until VC-3 signal 310 has been mapped into OC-12 signal 250.
- matrix 34 is capable of mapping a variety of level SPEs into a variety of levels of transport signals. For example, in mapping SONET-based SPEs into SDH-based transport signals, matrix 34 can map STS-1 and STS-3C SPEs into STM-1E, STM-10, STM-4, or STM-16 SDH transport signals as applicable. In addition, matrix 34 can map STS-12C SPEs into STM-4 or STM-16 SDH transport signals.
- matrix 34 can map, for example, VC-3 or VC-4 SPEs into OC-3, OC-12 and OC-48 transport signals.
- matrix 34 can map VC-4-4c SPEs into, for example, OC-12 or OC-48 SONET transport signals.
- Matrix 34 can also map higher level concatenated signals. The present invention is not intended to be limited by the level of signals mapped.
- FIGURE 3 is a block diagram of performance monitoring unit 30 of first network element 12 (from FIGURE 1) .
- performance monitoring unit 30 is preferably operable to proceed with performance monitoring functions differently depending on the format of the signals received.
- performance monitoring unit 30 includes a signal identifier 330, which receives SPE 26 from SPE decoder 18.
- Signal identifier 330 operates to identify the format of incoming SPE 26.
- the illustrated embodiment shows signal identifier 330 residing within performance monitoring unit 30, signal identifier 330 could alternatively reside within SPE decoder 18, or 16
- Performance monitor 30 also includes path tracers 336 and 338, which receive SONET-based and SDH-based SPEs 26, respectively.
- Each path tracer 336 and 338 performs a path trace function according to standards associated with the format of each signal received.
- path tracers 336 and 338 could alternatively be replaced with a single path tracer capable of performing an appropriate path trace function according to the format of each signal being monitored.
- a path trace is a performance monitoring function which ensures that information received at a destination network element has not been misconnected during its transmission through the network. The path trace function may be particularly important where sensitive information is transmitted through a network, and it is desirable to ensure that the information has not been misconnected through inappropriate network elements during transmission.
- the path trace function is typically implemented by inserting a known path trace message into a Jl byte of the overhead portion of each signal, and, after transmission, comparing the contents of the Jl signal to the known path trace message.
- the path trace message may be "known” in the sense that a terminating network element has been provisioned to recognize a particular message.
- the path trace message may be "known” in the sense that intermediate network elements can learn the repetitive message as it is received.
- performance monitoring unit 30 can be operable to create an event, such as an alarm condition notifying the network manager that the signal's path integrity has been compromised. Where path misconnections are identified, each signal's path through the network can be traced at each network element, to determine where the signal deviated from its intended path.
- each signal's path trace message is defined differently by SONET and SDH standards.
- the SONET domain defines the Jl path trace message as a repetitive 64-byte message comprising printable American Standard Code for Information Interchange (ASCII) characters terminated with carriage return and line feed characters.
- ASCII American Standard Code for Information Interchange
- the Jl path trace message comprises a 16-byte frame for the transmission of Section Access Point Identifiers, wherein the first byte of the string is a frame start marker and includes the result of a CRC-7 (error detection) calculation over the previous frame.
- CRC-7 error detection
- Performance monitoring unit 30 operates to perform the path trace function differently depending on the format of the signal received. Additional details of the operation of path tracers 336 and 338 will be explained below.
- Performance monitoring unit 30 further includes error detectors 332 and 334 coupled to signal identifier 330.
- error detectors 332 and 334 operate to perform a parity check on the data contained in each signal, and to compare the results of that parity check to data contained in a B3 byte of the synchronous path and associated overhead portion of each signal.
- network element 12 receives both SONET and SDH-based signals, it is advantageous for performance monitor 30 to handle error detection differently, depending on the format of each signal received.
- error detector 332 receives SPEs having the SONET format
- error detector 334 receives SPEs having the SDH format.
- Error detectors 332 and 334 report errors in the incoming signals according to procedures associated with each signal's format.
- the present embodiment illustrates the use of separate error detectors 332 and 334 for SONET and SDH- based signals, respectively, a single error detector capable of conducting error detecting and reporting functions according to the format of each signal received, could alternatively be used.
- Performance monitoring unit 30 can also comprise various other functional modules operable to facilitate various other performance monitoring functions in accordance with procedures associated with the format of each signal received.
- performance monitoring unit 30 can be operable to perform verification of signal label match.
- FIGURES 4A and 4B are flow charts illustrating exemplary methods of performing various monitoring functions on incoming signals.
- FIGURE 4A illustrates an exemplary method of providing a path trace monitoring function according to the teachings of the present invention.
- signal identifier 330 identifies the format of incoming SPE 26 at step 410.
- Signal identifier 330 can be operable to identify the format of SPE 26, for example, by examining the synchronous path and associated overhead portion of the signal. Because the format and a content of synchronous 19
- signal identifier 330 can identify the format of each signal by examining the Jl byte of each signal and looking for known characteristics associated with each format.
- signal identifier 330 looks for a recurring 64 byte pattern ending with a carriage return line feed to identify the signal as a SONET-based signal.
- Signal identifier 330 also looks for a 16 byte recurring pattern beginning with a one and followed by 15 zeros to identify the signal as an SDH-based signal.
- Signal identifier 330 could look for any known pattern to identify the format of the signals received.
- performance monitoring unit 30 is operable to respond appropriately, depending on the format of the signal received.
- signal identifier 330 identifies SPE 26 as having a SONET-based format at step 412
- path tracer 336 operates to print the ASCII characters contained in the Jl byte of the synchronous path and associated overhead of SPE 26 at step 414.
- Path tracer 436 compares the printed ASCII characters to a known path trace message at step 416.
- performance monitoring unit 30 establishes that SPE 26 has been properly routed to first network element 12, and proceeds to examine the next frame of SPE 26 at step 430, which restarts the trace message. If, however, path tracer 336 establishes that the printed ASCII characters do not match the known path trace message at step 418, path tracer 336 can issue an alarm condition at step 420 to notify a network element manager (not 20
- path tracer 338 prints hexadecimal representations of the information contained in the Jl byte of SPE 26 at step 422.
- Path tracer 338 next compares the hexadecimal representation of the Jl byte information to a known path trace message at step 424.
- path tracer 338 If path tracer 338 establishes that the hexadecimal representation of the contents of the Jl byte match the known path trace message, it proceeds to monitor the next received signal at step 432. If, however, path tracer 338 establishes a mismatch between the hexadecimal representation of the contents of the Jl byte and the known path trace message at step 426, path tracer 338 may create an event, such as an alarm condition at step 428 notifying the network element manager (not explicitly shown) of a breach of signal integrity and/or path connections within the network.
- an alarm condition such as an alarm condition at step 428 notifying the network element manager (not explicitly shown) of a breach of signal integrity and/or path connections within the network.
- performance monitoring unit 30 may transmit these monitored characteristics to various other network elements to assist in detecting and correcting problem points within the network.
- FIGURE 4B is a flowchart illustrating an exemplary method of detecting errors in signals received at first network element 12.
- the method begins with performance monitoring unit 30 identifying the format of SPE 26 at step 510. If SPE 26 is identified as a SONET-based signal at step 512, error detector 332 performs a parity check on the contents of SPE 26 at step 514. Error detector 332 next compares the results of its parity check with the contents of the B3 byte of the synchronous path and associated 21
- error detector 332 continues to the next signal at step 522. If, on the other hand, any of the bits of the result from the parity check do not match the bits contained in the B3 byte of the previously received signal at step 518, error detector 332, in accordance with standards associated with SONET-based signals, reports the total number of errors detected at step 520. The total number of errors is equal to the number of mismatched bits between the result of the parity check and the contents of the B3 byte of the previously received SPE 26.
- error detector 334 proceeds to perform a parity check on the contents of SPE 26 at step 530. The results of this parity check are compared against the contents of the B3 byte of the previously received SPE 26 signal at step 532. If error detector 324 determines that all bits of the result of the parity check match associated bits in the B3 byte of the previously received signal at step 534, no errors are detected and error detector 334 proceeds to the next SPE 26 at step 538.
- Performance monitor 30 provides an advantage of facilitating various performance monitoring functions according to standards associated with the various formatted signals received.
Abstract
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Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
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EP99915192A EP1072115A1 (en) | 1998-03-31 | 1999-03-31 | System and method for trafficking telecommunication signals |
CA002326417A CA2326417A1 (en) | 1998-03-31 | 1999-03-31 | System and method for trafficking telecommunication signals |
JP2000541795A JP2002510900A (en) | 1998-03-31 | 1999-03-31 | Transport of communication signals |
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Application Number | Priority Date | Filing Date | Title |
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US09/052,918 | 1998-03-31 | ||
US09/052,918 US6477178B1 (en) | 1998-03-31 | 1998-03-31 | System and method and trafficking telecommunication signals |
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WO1999050986A1 true WO1999050986A1 (en) | 1999-10-07 |
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Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1999/007166 WO1999050986A1 (en) | 1998-03-31 | 1999-03-31 | System and method for trafficking telecommunication signals |
Country Status (5)
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US (1) | US6477178B1 (en) |
EP (1) | EP1072115A1 (en) |
JP (1) | JP2002510900A (en) |
CA (1) | CA2326417A1 (en) |
WO (1) | WO1999050986A1 (en) |
Cited By (6)
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WO2001080596A1 (en) * | 2000-04-12 | 2001-10-25 | Sycamore Networks, Inc. | Method for port connectivity discovery in transparent high bandwidth networks |
WO2002089375A2 (en) * | 2001-04-27 | 2002-11-07 | Marconi Uk Intellectual Property Ltd | A transmission method |
WO2003003632A1 (en) * | 2001-06-28 | 2003-01-09 | Nortel Networks Limited | Method and apparatus for transmitting synchronous data |
EP1282250A1 (en) * | 2001-07-30 | 2003-02-05 | Lucent Technologies Inc. | Method of transparently transporting frames with reduced overhead between two networks through an intermediate network using a common frame with expanded payload section |
FR2835990A1 (en) * | 2002-02-11 | 2003-08-15 | France Telecom | SYSTEM AND METHOD FOR DATA TRANSMISSION THROUGH A SYNCHRONOUS NETWORK |
WO2003065626A3 (en) * | 2002-01-31 | 2004-02-05 | Marconi Comm Spa | Communications system |
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US7643500B1 (en) * | 1996-10-22 | 2010-01-05 | Sprint Communications Company L.P. | Overhead replication for SONET signals |
EP1051057A3 (en) * | 1999-04-29 | 2004-07-28 | Alcatel | Transport of concatenated containers in a synchronous transmission network |
DE19943625A1 (en) * | 1999-09-11 | 2001-03-15 | Alcatel Sa | Method and device for converting a SONET signal into an SDH signal |
US6691169B1 (en) * | 2000-02-01 | 2004-02-10 | At&T Corp. | Method and apparatus for detecting route advertisement violations in a network of interconnected peers |
JP2001251267A (en) * | 2000-03-07 | 2001-09-14 | Fujitsu Ltd | Transmitter and mutual conversion method of signals |
ATE253791T1 (en) * | 2000-05-26 | 2003-11-15 | Cit Alcatel | METHOD FOR TRANSMITTING SYNCHRONOUS TRANSPORT MODULES OVER A SYNCHRONOUS TRANSPORT NETWORK |
US6836486B2 (en) * | 2000-12-21 | 2004-12-28 | Nortel Networks Limited | Switching of low order data structures using a high order switch |
US7016378B1 (en) * | 2001-01-26 | 2006-03-21 | Ciena Corporation | Method and system for automatically provisioning an overhead byte |
WO2002063861A1 (en) * | 2001-02-06 | 2002-08-15 | 2Wire, Inc. | Loop extender with communications, control, and diagnostics |
US7483528B2 (en) | 2001-02-06 | 2009-01-27 | 2Wire, Inc. | Loop extender with selectable line termination and equalization |
AU2002250093A1 (en) * | 2001-02-15 | 2002-08-28 | 2Wire, Inc. | System and method for fault isolation for dsl loop extenders |
US7353288B1 (en) * | 2001-10-17 | 2008-04-01 | Ciena Corporation | SONET/SDH payload re-mapping and cross-connect |
US20080112400A1 (en) * | 2006-11-15 | 2008-05-15 | Futurewei Technologies, Inc. | System for Providing Both Traditional and Traffic Engineering Enabled Services |
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-
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- 1999-03-31 EP EP99915192A patent/EP1072115A1/en not_active Withdrawn
- 1999-03-31 CA CA002326417A patent/CA2326417A1/en not_active Abandoned
- 1999-03-31 WO PCT/US1999/007166 patent/WO1999050986A1/en not_active Application Discontinuation
- 1999-03-31 JP JP2000541795A patent/JP2002510900A/en not_active Withdrawn
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WO2001080596A1 (en) * | 2000-04-12 | 2001-10-25 | Sycamore Networks, Inc. | Method for port connectivity discovery in transparent high bandwidth networks |
US6681248B1 (en) | 2000-04-12 | 2004-01-20 | Sycamore Networks, Inc. | Method for port connectivity discovery in transparent high bandwidth networks |
WO2002089375A2 (en) * | 2001-04-27 | 2002-11-07 | Marconi Uk Intellectual Property Ltd | A transmission method |
WO2002089375A3 (en) * | 2001-04-27 | 2003-01-03 | Marconi Comm Ltd | A transmission method |
US8040919B2 (en) | 2001-04-27 | 2011-10-18 | Ericsson Ab | Transmission method |
CN1320792C (en) * | 2001-04-27 | 2007-06-06 | 爱立信股份有限公司 | A transmission method |
US6999470B2 (en) | 2001-06-28 | 2006-02-14 | Nortel Networks Limited | Methods and apparatus for transmitting synchronous data |
WO2003003632A1 (en) * | 2001-06-28 | 2003-01-09 | Nortel Networks Limited | Method and apparatus for transmitting synchronous data |
EP1282250A1 (en) * | 2001-07-30 | 2003-02-05 | Lucent Technologies Inc. | Method of transparently transporting frames with reduced overhead between two networks through an intermediate network using a common frame with expanded payload section |
US7002957B2 (en) | 2001-07-30 | 2006-02-21 | Lucent Technolgies Inc. | Method of transporting frames of information between parts of a network through an intermediate network |
JP2005516530A (en) * | 2002-01-31 | 2005-06-02 | マルコニ コミュニケイションズ ソシエタ ペル アチオニ | Communications system |
WO2003065626A3 (en) * | 2002-01-31 | 2004-02-05 | Marconi Comm Spa | Communications system |
US7804853B2 (en) | 2002-01-31 | 2010-09-28 | Ericsson Ab | Communications system |
CN1625858B (en) * | 2002-01-31 | 2012-01-04 | 爱立信股份有限公司 | Method for transmitting service Information from input interface of network unit capable of exchanging different types of service Information to output interface |
WO2003069817A1 (en) * | 2002-02-11 | 2003-08-21 | France Telecom | System and method for the transmission of data in a synchronous network |
FR2835990A1 (en) * | 2002-02-11 | 2003-08-15 | France Telecom | SYSTEM AND METHOD FOR DATA TRANSMISSION THROUGH A SYNCHRONOUS NETWORK |
Also Published As
Publication number | Publication date |
---|---|
US6477178B1 (en) | 2002-11-05 |
CA2326417A1 (en) | 1999-10-07 |
JP2002510900A (en) | 2002-04-09 |
EP1072115A1 (en) | 2001-01-31 |
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