CN100571171C - A kind of method that realizes SNCP by serial monitoring function - Google Patents

Abstract

The invention provides a kind of method by TCM function realization SNCP, be applicable to the situation in one night SDH territory, TCM two source, comprise step: the SN that (a) disposes SNCP is set to intermediate node TCM functional mode; (b) SN of configuration SNCP detects the signal that is sent by two source end SN respectively; N1 or N2 byte have introducing alarm indication signal Incoming AIS information and protect channel signal effective in the signal that sends on detecting the work at present passage; then carry out switching action, business is switched to the protection passage by service aisle.The present invention is made as at the network element that has disposed SNCP and does not support sourcesink end functional mode and when it receives the signal that has TC-IAIS information, can normally switch and avoids service disconnection, or avoid switching continually.

Description

A kind of method that realizes SNCP by serial monitoring function

Technical field

The present invention relates to the SDH (Synchronous Digital Hierarchy) (SDH of optical communication field; Synchronous DigitalHierarchy) in; at the boundary of Virtual network operator to each subnet (SN; Sub Network) carries out the technology of quality-monitoring and fault location; relate in particular to the method that realizes SNCP by serial monitoring (TCM, TandemConnection Monitoring) function.

Background technology

The Optical synchronization digital transmission network is made up of some SDH network element, carries out synchronizing information transmission, multiplexing and cross-coupled network on optical fiber, is a kind of standard of relevant digital data transmission, is a kind of layered system.It has the standardized message structure grade of a cover, and has a kind of block frame structure, allowing to arrange abundant overhead-bits (is the remainder behind the deduction net load in the Network-Node Interface bit stream, comprise section overhead and path overhead), these overhead-bits account for 5% of whole signal, utilize software that it is handled, can strengthen the Operations, Administration and Maintenance ability of network greatly.

The TCM function is to utilize that specific byte realizes in the path overhead (POH, Path Overhead).According to the G.707 definition of (2003 editions), the serial connection layer is positioned between multiplex section layer and the channel layer, and serial connection is mainly used in interoffice communication occasion, the particularly boundary of heterogeneous networks operator.By the TCM function, each network just can know that what mistakes the network that enters oneself received and what mistakes have been passed to next network; Wherein the TCM function of higher order path is to realize by the N1 byte, and the TCM function of passage then is to realize by the N2 byte at a low price.

According to the G.707 suggestion of (2003 editions), the processing of TCM has two places: source end (TandemConnection source) and Su Duan (Tandem Connection sink).Wherein the end function that need finish in source has: the insertion of pointer regeneration and N1 or N2 byte, promptly receiving the administrative unit (AU that enters the source end, Administering Unit) during invalidating signal (AU-AIS, AU-LOP), automatically produce effective pointer, and the value that will introduce error count (IEC, Incoming Error Count) is arranged to " 1110 "; When receiving that useful signal enters, then add up the B3 error code, and generate the value of IEC according to the number of B3 errored block; The function that the place end need be finished has: detect, report and the loopback performance alarm, promptly receiving invalid AU signal or can not find the multi-frame indication or receive series connection-introducing alarm indication signal (TC-IAIS, Tandem Connection-Incoming Alarm Iindicationsignal) time, then send AU-AIS (Administering Unit-Alarm Iindicationsignal) toward the downstream, simultaneously toward the series connection-far-end of loopback in the other direction disappearance indication (TC-RDI, Tandem ConnectionRemote Defect Indication) and out disappearance indication (ODI, Outgoing Defect Indication) alarm; Recover series connection-Access Point Identifier (TC-API, Tandem Connection Access PointIdentifier), and with desired value relatively, under the mismatch situation, insert AU-AIS, simultaneously toward loopback TC-RDI and ODI alarm in the other direction toward the downstream; And series connection-far-end mistake indication TC-REI (TandemConnection Remote Error Indication), out wrong indication (OEI, Outgoing ErrorIndication), TC-RDI, ODI, TC-IEC alarm performance added up and detect.

In the subnet of supporting the TCM function, existing set-up mode has following several: the subnet of 1) supporting source end function; 2) subnet of support place end function; 3) do not support the subnet (just configuration is supported sourcesink end function and do not used the subnet of TCM function, and its function is left intact for N1 or the N2 byte to TCM, and just it is made punch-through process) of sourcesink end function.

Because SDH has only a TCM sublayer; so when selecting the SDH territory; two source ends might have been chosen; pass through the situation that arrives the territory of a Su Duan behind the individual subnet of N (N＞=1) more then; be the example in one night SDH territory, TCM two source as shown in Figure 1; wherein A, B subnet are set to the source end; (wherein the business through A is a service aisle to have disposed a SNCP business through A, B at the C subnet; business through B is the protection passage); the H subnet is set to Su Duan, and the flow direction under the professional normal condition is to arrive H from A through C.If this moment, B subnet signal was effective, and the A subnet is received the invalid signals that enters source end AU, and then A subnets source end will produce effective pointer automatically after receiving this invalid signals, and transmission contains the TC-IAIS signal to the C subnet; If but the C subnet is not support sourcesink end function, N1 or the N2 byte received are just made punch-through process, and TC-IAIS neither cause the condition that SNCP is switched; So the C subnet just can't produce by the TC-IAIS information that the A subnet is given and switch, and promptly business can't be switched to from the useful signal that the B subnet is come, and causes service disconnection; And the business that arrives the H subnet can have TC-IAIS information always, thereby the regular traffic of H subnet is affected thus.

Because of above-mentioned situation can cause service disconnection, so must try every possible means to evade.Make the processing of support if will not support sourcesink end functional mode by certain approach (such as software) to TC-IAIS; promptly allow the subnet of not supporting sourcesink end functional mode that the signal that has TC-IAIS information is forcibly produced the function that SNCP is switched; so after this subnet has disposed SNCP; if receive N1 or N2 byte constantly for the subnet that does not use the TCM function; just may have TC-IAIS information randomly; will occur so again frequently switching professional phenomenon, make normal business to stablize and carry out.

Summary of the invention

Technical problem to be solved by this invention provides a kind of method that realizes SNCP by serial monitoring function, to solve the defective that prior art exists: under the situation of choosing one night SDH territory, TCM two source, when the network element that has disposed SNCP is made as when not supporting sourcesink end functional mode, receive that at it signal that has TC-IAIS information do not switch and cause service disconnection; Perhaps switch continually and influence that regular traffic is stable to carry out.

For achieving the above object, the invention provides a kind of method by serial monitoring function realization SNCP, be applicable to that described method comprises step by two TCM source end SN and the SDH territory that TCM place end SN forms:

(a) SN that disposes SNCP is set to intermediate node TCM functional mode;

(b) SN of configuration SNCP detects the signal that is sent by two source end SN respectively, N1 or N2 byte have the alarm indication signal Incoming AIS information of introducing in the signal that sends on detecting the work at present passage, and the protection channel signal is effective, then carry out switching action, business is switched to the protection passage by service aisle;

Wherein, service aisle is meant the service route that is arrived place end SN under the regular traffic situation by the first source end SN through the SN of configuration SNCP; The protection passage is the service route that is arrived place end SN by the second source end SN through the SN of configuration SNCP; The bit1 to bit4 of N1 byte has Incoming AIS information when being " 1110 ", the bit4 of N2 byte has IncomingAIS information when being " 1 ".

Further, step (b) N1 byte is used to realize the TCM function of higher order path; The N2 byte is used to realize the TCM function of low order channel.

Further, the first source end SN will generate pointer automatically when entering the administrative unit AU invalidating signal of source end, and transmission contains the signal of Incoming AIS information to the SN that disposes SNCP.

Further, the inventive method also comprises step: (c) SN of configuration SNCP does punch-through process to the content of N1 or N2 byte, is transparent to the downstream.

Further, the preceding step that also comprises of step (a): in the SN set-up mode of supporting the TCM function, add intermediate node TCM functional mode.

The present invention is by adopting the TCM function of intermediate node mode; to under the situation of choosing one night SDH territory, TCM two source; can make network element generation normally after receiving the signal that has TC-IAIS information of configuration SNCP switch, thereby the assurance business is not interrupted.In addition; intermediate node mode of the present invention has avoided not supporting sourcesink end functional mode to produce switch function to receiving the TC-IAIS information signal; thereby guaranteed in regular traffic is used; when the network element that has disposed SNCP is set to not support sourcesink end functional mode, just can after it receives at random the TCM information signal that has TC-IAIS professional phenomenon of frequently switching not appear.

Description of drawings

Fig. 1 is the schematic diagram in one night SDH territory, existing TCM two source;

Fig. 1 a is the example schematic in one night SDH territory, TCM of the present invention two source;

Fig. 2 is a SDH frame structure expense definition schematic diagram;

Fig. 3 is a TCM overhead byte N1 multi-frame structure definition schematic diagram;

Fig. 4 is a TCM overhead byte N2 multi-frame structure definition schematic diagram.

Embodiment

The method that realizes SNCP by serial monitoring TCM function provided by the invention, be applicable to by two TCM source terminal nets and the SDH (Synchronous Digital Hierarchy) SDH territory that TCM place terminal net is formed, this method has been introduced the TCM function of intermediate node mode, comprises step: the subnet that (a) disposes SNCP is set to intermediate node TCM functional mode; (b) detect the signal of coming respectively by two TCM source terminal network transmissions, N1 or N2 byte have the alarm indication signal Incoming AIS information of introducing in the signal of the TCM source terminal network transmission on detecting the work at present passage, and the protection channel signal is effective, then carry out switching action, business is switched to the protection passage by service aisle; (c) content of N1 or N2 byte is done punch-through process, be transparent to the downstream.

Below in conjunction with embodiment and accompanying drawing optimum implementation of the present invention is described in detail.

G.707 the SDH frame structure of (2003 editions) definition as shown in Figure 2.The path overhead that is used for the TCM function has N1 and N2, and the TCM function of higher order path realizes that by the N1 byte TCM function of passage then is to realize by the N2 byte at a low price.

Wherein, Fig. 3 and Fig. 4 are seen in the definition of the multi-frame structure of N1, N2 byte respectively, and the TCM function of SDH all is to resolve application according to the structure of 76 multi-frames.But for the detection of TC-IAIS, the N1 byte only need receive that bit1 to bit4 is " 1110 ", and the N2 byte only need receive that bit4 is " 1 ".

Embodiment as shown in Figure 1a; A; B; C and H are subnets; A wherein; the B subnet is set to TCM source end mode; the H subnet is set to TCM place end mode; the C subnet is set to intermediate node TCM functional mode (at first should add intermediate node TCM functional mode in the subnet set-up mode of supporting the TCM function); and disposed one through A at the C subnet; the SNCP business of B; wherein the business through A is a service aisle; business through B is the protection passage; the signal of these two passages is all effective; the alarm of triggerless channel switching, and do not have TC-IAIS information, the flow direction under the professional normal condition is to arrive H from A through C at this moment.The treatment step of C subnet (intermediate node TCM functional configuration subnet) under operate as normal is as follows so:

(a) detect the signal of coming respectively, the Incoming AIS information of N1 or N2 byte in the analytic signal by A, B subnet;

(b) have TC-IAIS information in the signal that the subnet on detecting the work at present passage is come, and the protection channel signal is effective, then carries out switching action, and business is switched to the protection passage;

(c) do not change the content of N1 or N2 byte, this byte is done punch-through process, be transparent to the downstream.

If so enter source end AU invalidating signal in the A subnet, the A subnet will generate pointer automatically so, and send TC-IAIS information to the downstream, and the C subnet just switches to business the signal that reception B subnet is come after receiving this signal, and the service route of this moment is exactly to arrive H from B through C.

Present embodiment adopts the TCM function of intermediate node mode; to under the situation of choosing one night SDH territory, TCM two source; make the C subnet that disposes SNCP after receiving the signal that has TC-IAIS information, can normally produce and switch, thereby the assurance business is not interrupted.In addition; intermediate node mode of the present invention has guaranteed in regular traffic is used; when the network element that has disposed SNCP is set to not support sourcesink end functional mode, professional phenomenon of frequently switching can not appear after it receives at random the TCM information signal that has TC-IAIS.

Certainly; the present invention also can have other multiple enforcements; under the situation that does not deviate from spirit of the present invention and essence thereof; those of ordinary skill in the art work as can be according to the present invention; make various corresponding changes and distortion, but these corresponding changes and distortion all should belong to the protection range of the appended claim of the present invention.

Claims (5)

1, a kind of method by serial monitoring function realization SNCP is applicable to that described method comprises step by two serial monitoring TCM source terminal net SN and the SDH (Synchronous Digital Hierarchy) SDH territory that TCM place end SN forms:

(a) SN that disposes SNCP is set to intermediate node TCM functional mode;

(b) SN of described configuration SNCP detects respectively by described two signals that source end SN sends, N1 or N2 byte have the alarm indication signal Incoming AIS information of introducing in the signal that sends on detecting the work at present passage, and the protection channel signal is effective, then carry out switching action, business is switched to the protection passage by service aisle;

Wherein, described service aisle is meant the service route that is arrived described place end SN under the regular traffic situation by the first source end SN through the SN of described configuration SNCP;

Described protection passage is the service route that is arrived described place end SN by the second source end SN through the SN of described configuration SNCP;

The bit1 to bit4 of described N1 byte has Incoming AIS information when being " 1110 ", the bit4 of described N2 byte has Incoming AIS information when being " 1 ".

2, in accordance with the method for claim 1, it is characterized in that the described N1 byte of step (b) is used to realize the TCM function of higher order path; Described N2 byte is used to realize the TCM function of low order channel.

3, in accordance with the method for claim 1; it is characterized in that; the described first source end SN will generate pointer automatically when entering the administrative unit AU invalidating signal of source end, and transmission contains the SN of the signal of described IncomingAIS information to described configuration SNCP.

4, in accordance with the method for claim 1, it is characterized in that described method also comprises step: (c) SN of described configuration SNCP does punch-through process to the content of described N1 or N2 byte, is transparent to the downstream.

5, in accordance with the method for claim 1, it is characterized in that the preceding step that also comprises of step (a): in the SN set-up mode of supporting described TCM function, add described intermediate node TCM functional mode.

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