CN1791096A

CN1791096A - Method for distinguishing LP-S and SF-P request in multiplex section protection

Info

Publication number: CN1791096A
Application number: CN 200410098488
Authority: CN
Inventors: 王光军
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2004-12-13
Filing date: 2004-12-13
Publication date: 2006-06-21
Anticipated expiration: 2024-12-13
Also published as: CN100542168C

Abstract

The invention relates to a method to distinguish LP-S and SF-P in multiplexing segment protection. Wherein, transmitting the identification request information for LP-S and SF-P between two net elements with non-spending byte of K1 and K2 to send LP-S information to opposite end net element and make two ends known the send of LP-S command. This invention can recognize LP-S request on two-end net element accurately to distinguish LP-S and SF-P request for different treatment ways.

Description

Distinguish the method for LP-S and SF-P request in the multiplex section protection

Technical field

The present invention relates to network service resist technology field, relate in particular to the method for distinguishing LP-S (segment protection locking) and SF-P (Signal Fail protection) request in a kind of multiplex section protection.

Background technology

Multiplex section protection is a kind of main salvo in the SDH/SONET equipment; owing to have the response time of switching weak point; support perfect APS (APS) agreement and abundant outside to switch order, switch the reliability advantages of higher, therefore in optical-fiber network, used widely.

Multiplex section protection is to transmit the APS turning protocol by the K1 of the multiplex section of SDH/SONET and K2 overhead byte, and the definition of these two overhead bytes is as shown in table 1:

Table 1:

K1		K2
K1		K2			1	2	3	4	5	6	7	8	1	2	3	4	5	6	7	8
Switching request	Destination node number	Source node number	The line of apsides	Switch status	1	2	3	4	5	6	7	8	1	2	3	4	5	6	7	8

As known from Table 1, wherein low four of K1 are transmitted switching request, owing to have only four, so can only distinguish 16 kinds of different switching request, according to G.841 standard code, the value of corresponding various switching request is as shown in table 2 respectively:

Table 2:

	Bridge Request code(Bits D1-D4)
	Bridge Request code(Bits D1-D4)	Bits

D1 D2 D3 D4
D1 D2 D3 D4		1 1 1 1	Signal Fail(Protection)SF-P/Lockout of Protection(Span)LP-S
1 1 1 0	Forced Switch(Span)FS-S	1 1 1 1	Signal Fail(Protection)SF-P/Lockout of Protection(Span)LP-S
1 1 1 0	Forced Switch(Span)FS-S	1 1 0 1	Forced Switch(Ring)FS-R
1 1 0 0	Signal Fail(Span)SF-S	1 1 0 1	Forced Switch(Ring)FS-R
1 1 0 0	Signal Fail(Span)SF-S	1 0 1 1	Signal Fail(Ring)SF-R
1 0 1 0	Signal Degrade(Protection)SD-P	1 0 1 1	Signal Fail(Ring)SF-R
1 0 1 0	Signal Degrade(Protection)SD-P	1 0 0 1	Signal Degrade(Span)SD-S
1 0 0 0	Signal Degrade(Ring)SD-R	1 0 0 1	Signal Degrade(Span)SD-S
1 0 0 0	Signal Degrade(Ring)SD-R	0 1 1 1	Manual Switch(Span)MS-S
0 1 1 0	Manual Switch(Ring)MS-R	0 1 1 1	Manual Switch(Span)MS-S
0 1 1 0	Manual Switch(Ring)MS-R	0 1 0 1	Wait-To-Restore WTR
0 1 0 0	Exerciser(Span)EXER-S	0 1 0 1	Wait-To-Restore WTR
0 1 0 0	Exerciser(Span)EXER-S	0 0 1 1	Exerciser(Ring)EXER-R
0 0 1 0	Reverse Request(Span)RR-S	0 0 1 1	Exerciser(Ring)EXER-R
0 0 1 0	Reverse Request(Span)RR-S	0 0 0 1	Reverse Request(Ring)RR-R
0 0 0 0	No Request NR	0 0 0 1	Reverse Request(Ring)RR-R

As can be seen from Table 2, SF-P, LP-S use identical value to represent in the signaling of k byte transmission.Therefore, when switching, actually or the opposite end network element of the section of switching can't be distinguished switching request SF-P request LP-S request according to the switching request field value in the k1 byte in the signaling of receiving, promptly when the switching request field in the signaling of receiving is the 0xf value node can't to distinguish be SF-P or LP-S.

And the protocol processes process that regulation SF-P request and LP-S ask in standard G.841 is inequality; for example; under the situation of loop multiplexing section protection; SF-P with can coexist with the ring switching request of section; but LP-S does not but allow to have any ring switching with section; thereby, will have influence on concrete protocol processes if on network element, can't distinguish SF-P, LP-S request.

In addition, on annular and Linear multiplex section, if can not effectively distinguish SF-P, LP-S request, also will cause under the situation of inquiry multiplexing segment status, the multiplexing segment status of switching an end network element of section is SF-P, and the multiplexing segment status of other end network element is LP-S, misreads thereby produce multiplexing segment status.

For this reason, need a kind of technical scheme and can realize after network element is received switching request, can distinguish switching request is SF-P or LP-S request.

At present a kind of method that adopts is: utilize the RDI (remote bug indication) in the switch status field that the Senior Three position of the k2 byte in the overhead byte transmits to distinguish.When the switching request field of receiving is 0xf, judge then whether the value of switch status field is 0x6, if, determine that then switching request is SF-P, if the value of switch status field is not 0x6, then switching request is LP-S.

Yet this method can only effectively be distinguished LP-S and SF-P request under specific circumstances, and can't realize distinguishing SF-P, LP-S request effectively in some cases.

As shown in Figure 1; if issue the LP-S order at the east orientation of network element A, and the protection optical fiber of the section between the hypothesis AB all is under the good situation, and then the switching request field of the k byte received of B is 0xf; the switch status field is not 0x6, so B can judge that the switching request of receiving is LP-S.

Yet when situation that protection optical fiber breaks appearred in the AB section, B can't receive the k byte (having only the minor axis direction to insert RDI) of minor axis direction, so network element B can't know that at all network element A issues the situation of LP-S order; If receiving fibre, the protection of the east orientation of network element A breaks; east orientation at network element A issues the LP-S order simultaneously; then can receive the signaling that the k byte is transmitted; the switching request field of described k byte is 0xf; the switch status field is 0x6; therefore, judge that the switching request of receiving is SF-P, but in fact should be that the LP-S request is worked.Cause SF-P, LP-S to ask erroneous judgement.

At present the another kind of technical scheme that adopts is: the method that undefined two value 0x4,0x5 differentiation SF-P, LP-S in regulation G.841 are provided among U.S. Pat 2002/0039348 A1 in the switch status field among a kind of k2 of use.

As can be seen, in said method, can carry out the differentiation of SF-P, LP-S request at the situation among Fig. 1.Promptly having solved A end east orientation issues LP-S and (perhaps detects SF-P; the east orientation protection that is A is received fine disconnected); and the west of B to this locality have SF-R request (be B the west to work and the receipts fibre of protection all break) under the situation, the differentiation problem that SF-P, LP-S ask when carrying out multiplex section rearrangement.This is because can coexist at AB section SF-P and SF-R, and LP-S need seize SF-R, therefore, must SF-P and LP-S be distinguished by undefined two values in the switch status field, and above-mentioned patent has solved this problem effectively.

But, next this scheme will lose efficacy if also there is the situation of switching request in other sections except that AB, because the k byte of the major diameter that A sends can not be delivered to B, be SF-P or LP-S from the request of corresponding value judgement A from the k byte that A sends that receives in the method that network element B also just can't provide according to patent US 2002/0039348 A1 naturally.Therefore, this method still has significant limitation.

Summary of the invention

In view of above-mentioned existing in prior technology problem; the purpose of this invention is to provide the method for distinguishing LP-S and SF-P request in a kind of multiplex section protection; can effectively distinguish LP-S under the various situations and SF-P request, for turning protocol is handled and switch status is inquired about convenience is provided.

The objective of the invention is to be achieved through the following technical solutions:

The invention provides the method for distinguishing LP-S and SF-P request in a kind of multiplex section protection, comprising:

After A, the network element reception area segment protect locking LP-S order, send LP-S request notice message to the opposite end network element;

After B, opposite end network element are received described notice message, write down this LP-S solicited message;

C, when the opposite end network element is received the switching request that is designated LP-S or SF-P request, determine that according to the information of record the switching request of receiving is the LP-S request.

Described steps A comprises:

Described LP-S request notice message is sent to the opposite end network element by data communication channel DCC or special-purpose control channel.

Described step B comprises:

The opposite end network element adopts the request attribute sign that is provided with separately to write down the information of the next LP-S order of other end network element transmission.

Described step C comprises:

The opposite end network element receives that the switching request of the switching request field of K byte is 0Xf, then whether inquiry has been write down other end network element and has been issued the LP-S information requested, if determine that then the switching request of receiving is the LP-S request, otherwise, determine that described switching request is the SF-P request.

Described step B also comprises:

B1, opposite end network element return the response message of LP-S request notice message to other end network element;

B2, other end network element judge in the time of setting whether receive described response message, if receive, then order the information that has issued at local terminal network element record LP-S, otherwise the local terminal network element issues the information of not having response to issuing LP-S order end return command.

Described step B2 also comprises:

After the local terminal network element issues the information of not having response, also send the message of removing the LP-S request to the opposite end network element, after the opposite end network element was received described message, the request attribute of its record sign was set to not have request.

The method of distinguishing LP-S and SF-P request in the described multiplex section protection also comprises:

When D, network element are received described removing LP-S order, check whether local network element records the information that the LP-S order has issued, if having, execution in step E then, otherwise, execution in step F;

The message of LP-S request is removed in E, generation, and sends to the opposite end network element, and after the opposite end network element was received described message, the request attribute of its record sign was set to not have and asks;

F, to issuing the information of removing LP-S order end return command mistake.

Described step e also comprises:

The opposite end network element returns response message to the local terminal network element;

The local terminal network element judges in the time of setting whether receive described response message, if receive, has then descended photos and sending messages to be revised as the LP-S order of record and has not had request, and carried out protocol processes in view of the above.Otherwise, issue no response message to issuing removing LP-S order end return command.

As seen from the above technical solution provided by the invention, the present invention carries out the transmission of LP-S and SF-P request identifying information between the network element of two ends by the mode of non-K1, K2 overhead byte, thereby make the two ends network element all can know issuing of LP-S order.Therefore, realization of the present invention has guaranteed in the multiplex section protection process, and the two ends network element that issues the LP-S order all can accurately identify the LP-S request, divides corresponding LP-S and SF-P request with active zone, handles in different ways respectively.Simultaneously, the present invention also can be so that the switch status of network element be more easy to identify.

Description of drawings

Fig. 1 is a multiplex section protection ring network structure schematic diagram;

Fig. 2 is the flow chart of method of the present invention.

Embodiment

Core of the present invention is to adopt the mode of non-K1, K2 byte overhead (as by the data communication channel mode etc.) to carry out the communication between network element, passing to the opposite end network element to the LP-S command information that network element issues, make the opposite end network element can be not just can not know the issuing of LP-S order of this section, and then made things convenient for the processing of agreement and the inquiry of network element protocol status by the transmission of k byte.

The main processing procedure of method of the present invention comprises:

At first, when webmaster issues LP-S when order to the local terminal network element, then the local terminal network element sends LP-S request notice message to the opposite end network element;

The opposite end network element issues the information that LP-S orders according to the described notice message accounting other end network element of receiving, and returns response message to the local terminal network element, issues so that the local terminal network element is confirmed the LP-S order;

Like this, when the opposite end network element is received the switching request that the local terminal network element sends, when maybe needing to inquire about the opposite end switch status, then can determine whether request according to the information of wherein keeping records into LP-S.

The specific implementation of method of the present invention specifically may further comprise the steps as shown in Figure 2:

Step 21: in the multiplex section protection process, webmaster issues the LP-S order to certain network element A, as shown in Figure 1, supposes that network element A receives the LP-S order that issues, and is called the local terminal network element, and network element B is the network element with the other end of section, is called the opposite end network element;

Step 22: after network element A received the LP-S order that webmaster issues, then to the opposite end network element, promptly network element B sent LP-S request notice message, is used to notify network element B this section that the LP-S request takes place;

Step 23: opposite end network element B receives after the described LP-S request notice message, the request attribute sign (can be called attribute 1) that utilize to be provided with in this locality is noted the information of the LP-S order that network element A issues, and the effect of attribute 1 is whether the network element of sign opposite end has issued the LP-S order;

Step 24: network element B also needs to send to network element A the response message of described LP-S request notice message when revising attribute 1 information;

Step 25: network element A judges in the time of setting whether receive described response message, if receive, then execution in step 26, otherwise, execution in step 27;

If network element B receives the LP-S request notice message of network element A, perhaps network element A does not receive the response message of network element B, then network element A in the time of setting (as 3 seconds) overtime after, will not receive the response message of network element B;

Step 26: after network element A receives response message, switch record LP-S order during record LP-S order has issued in the order sign (can be called attribute 2) in the outside of network element A, and carry out protocol processes, simultaneously, execution in step 29;

Step 27: network element A returns the webmaster order and issues the return information that can not get carrying out, and sends the message of removing LP-S to network element B simultaneously;

Step 28: after network element B receives the message of described removing LP-S, the information of record in the clearsanattribute 1 then, and be set to NR (not having request), and simultaneously, execution in step 29;

Step 29: network element B waits for and receives the switching request that network element A sends;

Step 210: network element B is in the switching request of receiving the k byte that network element A sends, and the switching request of switching request field is 0xf;

Step 211: determine that according to the attribute 1 that network element B preserves described switching request is LP-S request or SF-P request;

Network element B judges whether attribute 1 writes down network element A and issue the LP-S order, if, determine that then described switching request is the LP-S request, otherwise, determine that described switching request is the SF-P request;

Through the processing procedure of front, in this step, can know just that according to the information of attribute 1 record the switching request of receiving is the SF-P request, or the LP-S request, so that it is handled accordingly;

Among the present invention, in the time of the needs switching status inquiry, if the switching request of local record is 0xf, then equally need be according to the information of record in the attribute 1 of this locality, or actually know this switching request LP-S SF-P, like this, the demonstration switch status that webmaster just can be correct.

Method of the present invention also comprises the processing procedure of webmaster when certain network element issues removing LP-S order.Suppose that still LP-S switches order and issues to network element A, network element B is the network element with the other end of section, and concrete processing procedure comprises:

(1) if issue removing LP-S order to network element B, because the value in the local attribute 2 of network element B is not 0xf, promptly webmaster did not issue LP-S to network element B and switched order, and at this moment, network element B is to the information of webmaster return command mistake.

(2) if issue to network element A and to remove the LP-S order, the value in the local attribute 2 of network element B is 0xf, and then network element A sends the message of removing LP-S to network element B, with the value of the attribute 1 of removing network element B; Opposite end network element B receives after the message of removing LP-S, and the attribute 1 of this locality is reverted to NR, sends response message to network element A simultaneously.

If network element B does not receive the message of the removing LP-S of network element A, perhaps network element A does not receive the response message of network element B, then network element A 3 seconds overtime after, to issue the return information that can not get carrying out to the webmaster return command, promptly issue no response message to the webmaster order, notice webmaster, its order that issues can't obtain carrying out.Send the request notice message of LP-S simultaneously to network element B, be eliminated the inconsistent situation in the two ends that cause to prevent the attribute 1 among the network element B.

Receive at the response message of the message of removing LP-S as network element A, then the information that writes down in the attribute 2 of network element A is reverted to NR, and carry out protocol processes.

LP-S request notice message described in the present invention reaches the message of removing the LP-S order and all can transmit between network element by DCC (data communication channel) or designated lane, also can adopt other passages that can guarantee information reliable delivery between network element to transmit.

The above; only for the preferable embodiment of the present invention, but protection scope of the present invention is not limited thereto, and anyly is familiar with those skilled in the art in the technical scope that the present invention discloses; the variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of claims.

Claims

1, distinguish the method for LP-S and SF-P request in a kind of multiplex section protection, it is characterized in that, comprising:

2, distinguish the method for LP-S and SF-P request in the multiplex section protection according to claim 1, it is characterized in that described steps A comprises:

3, distinguish the method for LP-S and SF-P request in the multiplex section protection according to claim 1, it is characterized in that described step B comprises:

4, according to the method for distinguishing LP-S and SF-P request in claim 1, the 2 or 3 described multiplex section protections, it is characterized in that described step C comprises:

The opposite end network element receives that the switching request of the switching request field of K byte is OXf, then whether inquiry has been write down other end network element and has been issued the LP-S information requested, if determine that then the switching request of receiving is the LP-S request, otherwise, determine that described switching request is the SF-P request.

5, according to the method for distinguishing LP-S and SF-P request in claim 1, the 2 or 3 described multiplex section protections, it is characterized in that described step B also comprises:

6, distinguish the method for LP-S and SF-P request in the multiplex section protection according to claim 5, it is characterized in that described step B2 also comprises:

7, according to the method for distinguishing LP-S and SF-P request in claim 1, the 2 or 3 described multiplex section protections, it is characterized in that this method also comprises:

8, distinguish the method for LP-S and SF-P request in the multiplex section protection according to claim 7, it is characterized in that described step e also comprises: