CN102185719A - Service link tracking realization method and device - Google Patents

Abstract

The invention provides a service link tracking realization method and a service link tracking realization device, which are applied to a multi-protocol label switching-transport profile (MPLS-TP) network. The method comprises the following steps of: detecting the amount N of transmitting node equipment between a first maintenance end point and a second maintenance end point when a message is transmitted from the first maintenance end point to the second maintenance end point; transmitting a first loopback request message to the second maintenance end point, wherein the set time to live of the first loopback request message corresponds to time required by the transmission of the first loopback request message to the Mth node equipment, and M is less than or equal to N; and receiving a first loopback response message in response to the first loopback request message from the Mth node equipment, and reporting link information between the first maintenance end point and the Mth node equipment. By the method and the device, actual service traffic conditions between a source-end maintenance end point (MEP) and a destination-end MEP can be completely acquired, and the function of performing link tracking on a point-to-point co-routing bidirectional path in the MPLS-TP network is realized.

Description

Realize the method and apparatus that service link is followed the trail of

Technical field

The present invention relates to MPLS-TP (multiprotocol label switching transmits application) network transmission technology, relate in particular in the MPLS-TP network, realize point-to-point route two-way approach OAM (operation, management, maintenance) altogether, carry out the method and apparatus that service link is followed the trail of.

Background technology

MPLS-TP supports a kind of common route two-way approach of point-to-point, this path forward direction with the back to all along identical route (link and node), have on the LSP in the MPLS-TP network (Label Switched Path label switched path) and the PW (virtual link) application this path.

MPLS-TP is a kind of connection-oriented packet switching network technology, in April, 2008, the joint working group (JWT) that is set up by ITU-T (International Telecommunications Union's telecommunication standards tissue) and IETF (internet engineering task group) proposes, MPLS-TP=MPLS-L3 complexity+OAM+ protection, its feature comprises: utilize the MPLS label switched path, save MPLS signaling and IP sophisticated functions; Support multiple service supporting, be independent of client layer and key-course, and can run on various physical-layer techniques; Has powerful transfer capability: as QOS/OAM and reliability etc.

Describe correlation technique details and the realization of MPLS-TP OAM among the draft draft-bhh-mpls-tpoam-y1731-04 in detail, but do not provide definition and implementation for link tracing, only have only functional requirement analysis and general technical scheme now, as this demand of path tracing on the requirement documents IETFrfc5860 of MPLS-TP OAM, having occurred, still there is not concrete implementation; At MPLSArchitectural Considerations for a Transport Profile[Dave Ward, Malcolm Betts, ed.ITU-T-IETF Joint Working Team, April 18,2008] in, proposed to utilize the overdue mode of TTL (time to live) to realize safeguarding the communication of end end points MEP (Maintenance End Point) to Maintenance Intermediate Point MIP (Maintenance Intermediate Point), but for link tracing, the specific implementation method is also immature, can only realize that at first MEP arrives the communication of specifying MIP; Secondly, for sending the not definition of OAM message; At last, for how replying also not explanation.

Summary of the invention

The purpose of technical solution of the present invention provides a kind of method and apparatus of realizing that service link is followed the trail of, be applied in the MPLS-TP network, be used for complete syntople between source end MEP, destination MEP and the MIP and the source end MEP of obtaining to the professional actual circulation situation between the destination MEP, realize the link tracing function of route two-way approach altogether of the point-to-point in the MPLS-TP network.

For achieving the above object, one aspect of the present invention provides a kind of method that realizes that service link is followed the trail of, and is applied to multiprotocol label switching and transmits application MPLS-TP network, it is characterized in that described method comprises:

First safeguards end end-point detection message when described first safeguards that end endpoint transmission to the second is safeguarded the end end points, safeguards that described first end end points and described second safeguards the number N of institute's transmission node equipment between the end end points;

Described first safeguards that the end end points sends the first loopback request message to the described second maintenance end end points, it is corresponding that the set life span value of the wherein said first loopback request message and the described first loopback request message transfer to the required time of M node device, and wherein M is smaller or equal to N;

Described first safeguards that the end end points receives described M node device and responds the first loopback response message that the described first loopback request message is sent, and reports described first link information of safeguarding between end end points and described M the node device according to the described first loopback response message.

Preferably, above-mentioned described method, safeguard that described first the end end points sends in the step of the first loopback request message to the described second maintenance end end points, described first safeguards that the end end points sends N described first loopback request message at least, and the life span of each described first loopback request message value is inequality.

Preferably, above-mentioned described method, described method are applied on the label switching path LSP and virtual link PW in the MPLS-TP network, and the described first loopback request message of wherein said life span value representation can transmit the number of the node device of process before abandoning.

Preferably, above-mentioned described method, when the described first maintenance end end-point detection message is held end points from described first maintenance end endpoint transmission to the second maintenance, safeguard that described first holding end points and described second to safeguard holds the step of the number N of institute's transmission node equipment between the end points specifically to comprise:

Described first safeguards that the end end points sends one second loopback request message to the described second maintenance end end points;

Described first safeguards that the end end points receives described second and safeguards the second loopback response message of holding end points to respond described second loopback request message transmission, according to the described second loopback response message, calculate the described second loopback request message when described first safeguards that the end endpoint transmission is safeguarded the end end points to described second, safeguard that described first end end points and described second safeguards the number N of institute's transmission node equipment between the end end points.

Preferably, above-mentioned described method, described first safeguards that the end end points specifically comprises to the step that the described second maintenance end end points sends one second loopback request message:

Described first safeguards that it is the address of the described first maintenance end end points that the end end points is specified the source address of the described second loopback request message, and destination address is the address of the described second maintenance end end points;

Described first safeguards that the transmission sequence number that the end end points is provided with in the described second loopback request message is a predetermined value, and the life span value that the described second loopback request message is set simultaneously is a maximum;

Described first safeguards that the setting of end end points receives the predetermined period of time of the described second loopback response message from the described second maintenance end end points;

Described first safeguards the end end points according to described second address of safeguarding the end end points, and the outlet of searching the described second loopback request message sends the described second loopback request message.

Preferably, above-mentioned described method, described according to the described second loopback response message, calculate the described second loopback request message when described first safeguards that the end endpoint transmission is safeguarded the end end points to described second, safeguard that described first end end points and described second safeguards that the step of the number N of institute's transmission node equipment between the end end points specifically comprises:

Described first safeguards that the end end points obtains the life span value that is write down from the described second loopback response message, described first safeguards that the maximum life span value of being transmitted between end end points and the described second maintenance end end points deducts the life span value that is write down, obtain the described second loopback request message and safeguard the maximum hop count value of transmitting between end end points and the described second maintenance end end points described first, wherein said maximum hop count value deducts 1 value, equal the described second loopback request message when described first safeguards that the end endpoint transmission is safeguarded the end end points to described second, safeguard that described first end end points and described second safeguards the number N of institute's transmission node equipment between the end end points.

Preferably, above-mentioned described method, described first safeguards that the end end points also comprises after described second safeguards the step of holding end points to send one second loopback request message:

Described first safeguards that the end end points does not receive the described second loopback response message in described predetermined period of time, and then direct number N with the described second loopback request message institute transmission node equipment is set at 254.

Preferably, above-mentioned described method, described first safeguards that the end end points sends in the step of N the described first loopback request message at least, the life span value of setting the described second loopback request message is the wherein integer in 1 to N.

Preferably, above-mentioned described method, described first safeguards that the end end points after described second safeguards that the end end points sends the step of the first loopback request message, also comprises:

Described first safeguards that the node device between end end points and the described second maintenance end end points receives the described first loopback request message, and carries out following steps:

Step 1, described node device inquiry tag record sheet judges that when described node device was intermediate node, then execution in step two, judges that when described node device was tail node, then execution in step three;

Step 2, described node device judge whether the described life span value that is write down in the described first loopback request message is 1, if 1, then execution in step three, if be not 1, then execution in step four;

When step 3, described node device are configured to safeguard the end end points or safeguard the end intermediate point, then generate the described first loopback response message; When described node device is not configured to safeguard the end end points or safeguards the end intermediate point, then abandon the described first loopback request message;

Step 4, described node device subtracts one with the described life span value of the described first loopback request message, sends the described first loopback request message along the service message direction afterwards.

Preferably, above-mentioned described method, in described step 3, the step of the described first loopback response message of described generation: the transmission sequence number that described node device is provided with the described first loopback response message is identical with the transmission sequence number of the described first loopback request message that is received, and the life span value of the described first loopback response message is set to 255 simultaneously.

Preferably, above-mentioned described method, described first safeguards that the end end points after described second safeguards that the end end points sends the step of the first loopback request message, also comprises:

Described first safeguards that the node device between end end points and the described second maintenance end end points receives the described first loopback response message, and carries out following steps:

Steps A, described node device inquiry tag record sheet is judged when described node device is intermediate node, then execution in step B judges when described node device is tail node, then execution in step C;

Step B, described node device subtracts one with the described life span value in the described first loopback response message, sends the described first loopback response message along the service message direction afterwards;

Step C, described node device mates transmission sequence number in the described first loopback response message and the local transmission sequence number of preserving, and judges whether success of coupling, if the match is successful, execution in step D then; If coupling is unsuccessful, then execution in step E;

Step D, described node device reporting links tracked information;

Step e, described node device directly abandon the described first loopback response message.

The present invention also provides a kind of device of realizing that service link is followed the trail of, is applied to multiprotocol label switching and transmits application MPLS-TP network, and described device comprises:

The node device detecting unit is used for detection messages when described first safeguards that end endpoint transmission to the second is safeguarded the end end points, safeguards that described first end end points and described second safeguards the number N of institute's transmission node equipment between the end end points;

Packet sending unit, be used for safeguarding that to described second the end end points sends the first loopback request message, it is corresponding that the set life span value of the wherein said first loopback request message and the described first loopback request message transfer to the required time of M node device, and wherein M is smaller or equal to N;

The message receiving element, receive described M node device and respond the first loopback response message that the described first loopback request message is sent, report described first link information of safeguarding between end end points and described M the node device according to the described first loopback response message.

In the specific embodiment of the invention technique scheme at least one has following beneficial effect:

The described method and apparatus of the specific embodiment of the invention, in the MPLS-TP Network Transmission, by sending LB (Loopbak, the loopback message) calculates the number of source end MEP (MEP) to institute's transmission node equipment between the destination MEP (the 2nd MEP), also promptly determine the jumping figure of source end MEP to destination MEP, and according to MIP between source end MEP and the destination MEP, MEP is to the parsing of loopback response message, the transmission sequence number of each first loopback response message is mated with the transmission sequence number of being preserved, determine whether to receive the echo message of each node device between source MEP and the purpose MEP in the predetermined period of time, when not receiving the response of a node device wherein, link failure is described, can indicate which the node device fault in the link, therefore form the actual syntople information between each node device, obtain source end MEP, syntople between destination MEP and the MIP and source end MEP realize the point-to-point in the MPLS-TP network is total to the link tracing function of route two-way approach to the professional actual circulation situation between the destination MEP.

Description of drawings

Fig. 1 is the application scenarios instance graph of the described method of the specific embodiment of the invention;

Fig. 2 is the schematic flow sheet of the described method of the specific embodiment of the invention;

Fig. 3 is for adopting the described method of the specific embodiment of the invention, and node device receives the handling process schematic diagram behind the first loopback request message;

Fig. 4 is for adopting the described method of the specific embodiment of the invention, and node device receives the handling process schematic diagram behind the first loopback response message.

Embodiment

For making the purpose, technical solutions and advantages of the present invention clearer, describe the present invention below in conjunction with the accompanying drawings and the specific embodiments.

The method and apparatus that the described realization service link of the specific embodiment of the invention is followed the trail of, in the MPLS-TP Network Transmission, by sending LB (Loopbak, the loopback message) calculates the number of source end MEP (MEP) to institute's transmission node equipment between the destination MEP (the 2nd MEP), also promptly determine the jumping figure of source end MEP to destination MEP, and according to MIP between source end MEP and the destination MEP, MEP is to the parsing of loopback response message, the complete source end MEP that obtains is to destination MEP and to the syntople between the MIP and should business actual circulation situation, realizes the link tracing function of route two-way approach altogether of the point-to-point in the MPLS-TP network.

The described method of the specific embodiment of the invention comprises:

First safeguards end end-point detection message when described first safeguards that end endpoint transmission to the second is safeguarded the end end points, safeguards that described first end end points and described second safeguards the number N of institute's transmission node equipment between the end end points;

Described first safeguards that the end end points sends the first loopback request message to the described second maintenance end end points, it is corresponding that the set life span value of the wherein said first loopback request message and the described first loopback request message transfer to the required time of M node device, and wherein M is smaller or equal to N;

Described first safeguards that the end end points receives described M node device and responds the first loopback response message that the described first loopback request message is sent, and obtains described first link information of safeguarding between end end points and described M the node device according to the described first loopback response message.

The core technology thought that specific embodiment of the invention said method is adopted is:

1, adopt the LB message as the pass-along message between source MEP and MIP among the OAM and the purpose MEP and receive the response.

2, for source MEP to the calculating of carrying out the path between the purpose MEP, make source MEP cognitive to some extent, so that intermediate node is implemented link tracing for the link transmission path.

3, for source MEP to the LB message between the purpose MEP with distinguish to the LB message of intermediate node so that analyze syntople.

Below will be described in detail the described method and apparatus of the specific embodiment of the invention.

The application system of the described method of the specific embodiment of the invention is deployed in the MPLS-TP network by network management system with OAM(Operation Administration Maintenance) as shown in Figure 1, wherein can be applicable to comprise on LSP or the PW:

Two MEP: a MEP (source MEP), the 2nd MEP (purpose MEP) are configured in respectively on the node device at two ends; Two MIP: a MIP, the 2nd MIP are configured on the intermediary device; Wherein network management system can be managed arbitrary node on this network.

Utilize said structure, at the MPLS-TP network, the method flow diagram that described realization service link is followed the trail of comprises step as shown in Figure 2:

S201, source MEP configuration order starts the link tracing operation;

S202, source MEP construct the second loopback request message LBM;

S203, source MEP search the purpose outbound port of the second loopback request message, and the second loopback request message is sent along the service message sending direction;

S204, source MEP receives purpose MEP and responds the second loopback response message that the second loopback request message sends, according to the second loopback response message, calculate the LB message when source MEP transfers to purpose MEP, the number N of institute's transmission node equipment between source MEP and purpose MEP, also promptly according to the maximum hop count of the source MEP that obtains to LB message transmission between the purpose MEP, calculate the LB message when source MEP transfers to purpose MEP, the number N of institute's transmission node equipment between source MEP and purpose MEP (N equals the maximum hop count value and deducts 1);

S205, source MEP sends loopback request message group to purpose MEP, comprise N first loopback request message at least, wherein the set life span value of the first loopback request message transfers to the first loopback request message that wherein the required jumping figure of a node device is corresponding, and the set life span value of each first loopback request message is inequality; In addition, each first loopback request message is provided with a specific transmission sequence number (Transaction ID);

S206, the Maintenance Intermediate Point in the MEP receiving node equipment of source is responded the first loopback response message that the first loopback request message is sent, and carries out described specific transmission sequence number coupling and reporting links information according to the first loopback response message.

In the method for specific embodiment of the invention step shown in Figure 2, particularly, at step S202, the concrete steps that source MEP constructs the second loopback request message LBM comprise:

Source MEP constructs the second loopback request message, and the source address of specifying this second loopback request message is the address of source MEP, and destination address is the address of the purpose MEP of appointment;

The transmission sequence number that source MEP is provided with in the second loopback request message simultaneously is a fixed value A, as is 65535, as the sign that mails to MEP;

Life span (TTL) value that source MEP is provided with in LSP label or the PW label is 255, also the maximum life span value of promptly transmitting between source MEP and purpose MEP;

Source MEP sets the predetermined period of time that receives loopback response message LBR from purpose MEP.

At step S204, source MEP is according to the second loopback response message, calculates the second loopback request message when source MEP transfers to purpose MEP, between the step of number N of institute's transmission node equipment specifically comprise:

When the correct second loopback response message that source MEP receives in the predetermined period of time that step S202 sets that purpose MEP sends, take out the ttl value in LSP in the second loopback response message or the PW label, deduct this ttl value by 256 and then obtain maximum hop count value between source MEP and the purpose MEP, this maximum hop count value deducts 1, and to be the number that comprises the node device of purpose MEP between source MEP and the purpose MEP be N.

In addition, after step S203, when in the predetermined period of time that step S202 sets, not receiving the second loopback response message of purpose MEP transmission, determine that then the maximum hop count between source MEP and the purpose MEP is 255 as if source MEP.

At step S205, source MEP specifically comprises to the step that purpose MEP sends loopback message group:

Source MEP constructs at least N first loopback request message: the LBM (1), LBM (2), LBM (3) ..., LBM (N), wherein the set life span value of each first loopback request message transfers to the first loopback request message that wherein the required jumping figure of a node device is corresponding, and the set life span of each first loopback request message is worth inequality, as the life span value of LBM (1) is set, make the life span of LBM (1) corresponding, can transfer to first node device with the jumping figure that transfers to first node device; The life span value of LBM (2) is set, makes the life span of LBM (2) corresponding with the jumping figure that transfers to second node device; And the like, the respectively life span value of first loopback request message is set respectively.

For example, when the method for the invention was applied to LSP or PW and goes up, the TTL that LSP in LBM (1) message or PW label are set was 1, and the TTL of LSP or PW label is 2 in LBM (2) message ..., the TTL of LSP or PW label is N in LBM (N) message.

In addition, each first loopback request message LBM (1), LBM (2), LBM (3) ..., among the LBM (N), one specific transmission sequence number is set respectively, and those specific transmission sequence numbers are different from source MEP employed transmission sequence number A when purpose MEP sends the second loopback request message, best, each specific transmission sequence number is followed certain rule, be LBM (1) as the ordering of the first loopback request message, LBM (2), LBM (3) ..., during LBM (N), the transmission sequence number of each first loopback request message can adopt the rule of successively decreasing successively or progressively increasing to set, and is corresponding with ttl value.

Adopt above-mentioned process, when the node device between source MEP and the purpose MEP is MIP or MEP, when the ttl value of the first loopback request message that is received is 1, then can respond this first loopback request message, return the first loopback response message to source MEP, source MEP is by resolving each first loopback response message, promptly can grasp source end MEP to destination MEP and to the syntople between the MIP and should business actual circulation situation, realize the link tracing function of route two-way approach altogether of the point-to-point in the MPLS-TP network.

Below will receive the first loopback request message LBM at node device port on the MPLS-TP network is described in detail with the handling process that sends the first loopback response message LBR, the process of the concrete reception first loopback request message LBM comprises step as shown in Figure 3:

After S301, node device receive the first loopback request message, inquiry LSP label or PW label list;

S302 judges whether this node device is tail node, if LSP label or PW label list are recorded as label exchange (Swap) operation, illustrates that then this this node device is not a tail node, but intermediate node, execution in step S303 downwards; If LSP label or PW label list are recorded as label and eject (POP) operation, illustrate that then this node device is a tail node, then downward execution in step S304;

S303 judges whether the TTL in LSP or the PW label is 1, if 1, then enter step S304, if be not 1, then enter step S305;

S304 detects the OAM allocation list, judges whether this node device is configured to MIP, if testing result is for being, and execution in step S306 downwards then, if testing result is not for, then downward execution in step S307;

S305 carries out label exchange, and ttl value in the LSP of this first loopback request message or the PW label is subtracted one, and execution in step S308 downwards;

S306, this node device generates the first loopback response message, the transmission sequence number that this first loopback response message is set is identical with the transmission sequence number of the first loopback request message that is received, and the ttl value of this first loopback response message is set to 255 simultaneously, enters step S308;

S307, this node device abandon this first loopback request message, do not respond;

S308 searches the outbound port of the first loopback request message, and message is sent along the service message sending direction.

In addition, the MPLS-TP node device port receives the handling process of the first loopback response message LBR, as Fig. 4, comprising:

Step S401:MPLS-TP node device receives the first loopback response message;

Step S402, node device inquiry LSP label or PW label list judge whether this node device is tail node, if be recorded as Swap, then explanation is not a tail node but intermediate node is jumped into step S403; If be recorded as POP, then be illustrated as tail node, also be the MEP node, jump into step S404;

Step S403 carries out the label exchange, and TTL sends along the service message sending direction after subtracting one in LSP or the PW label, returns step S401;

Step S404, node device mates transmission sequence number in the first loopback response message and the local transmission sequence number of preserving, and judges whether coupling is successful; If the match is successful, then downward execution in step S405; If coupling is unsuccessful, then downward execution in step S406;

Step S405, node device is to network management system reporting links tracked information;

Step S406 directly abandons this first loopback response message.

According to above-mentioned step, network management system forms the actual syntople information of specifying between MEP, the MIP according to the information that source MEP node reports, or the indication link failure.If certain MIP or MEP have fault, so just can not receive corresponding link and follow the trail of successful information, promptly know where be out of order.

With application system shown in Figure 1 is example, by network management system OAM(Operation Administration Maintenance) is deployed on the MPLS-TP network LSP, and the idiographic flow of carrying out the described method of the specific embodiment of the invention is:

Network management system issues the link tracing order at source MEP;

Source MEP sends the second loopback request message to purpose MEP, and sets the predetermined period of time that receives loopback response message LBR from purpose MEP, and the TTL that sets in the LSP label is 255, and transmission sequence number is 65535;

The one MIP receives the second loopback request message, the analytic message form, the operation that obtains according to the LSP searching label is Swap, be intermediate node, and judge that the ttl value in the second loopback request message that is received is not 1, then a MIP carries out label exchange, the ttl value of the second loopback request message is subtracted a back send along the service message sending direction;

The 2nd MIP receives the second loopback request message that a MIP sends, the analytic message form, the operation that obtains according to the LSP searching label is Swap, be intermediate node, and judge that the ttl value in the second loopback request message that is received is not 1, then the 2nd MIP carries out label exchange, the ttl value of the second loopback request message is subtracted a back send along the service message sending direction;

Purpose MEP receives the second loopback request message that the 2nd MIP sends, the analytic message form, the operation that obtains according to the LSP searching label is POP, the record transmission sequence number, send it back the second loopback response message of answering the second loopback request message, and the entrained transmission sequence number of this second loopback response message is that the TTL of 65535, the second loopback response messages is 255, sends along the service message sending direction afterwards;

The 2nd MIP receives the second loopback response message that purpose MEP sends, the analytic message form, the operation that obtains according to the LSP searching label is Swap, and the TTL that judges the second loopback response message is not 1, then carry out the label exchange, TTL is subtracted one (also being that TLL is 254) back send the second loopback response message;

The one MIP receives the second loopback response message that the 2nd MIP sends, the analytic message form, the operation that obtains according to the LSP searching label is Swap, and the TTL that judges the second loopback response message is not 1, then carry out the label exchange, TTL is subtracted one (also being that TLL is 253) back send the second loopback response message;

Receive the second loopback response message in the MEP predetermined period of time of source, the analytic message form, the operation that obtains according to the LSP searching label is POP, the transmission sequence number of judging the second loopback response message is 65535, respond the response bag that the second loopback request message sends according to the definite second loopback response message that is received of this transmission sequence number for purpose MEP, TTL in the record LSP label is 253, the maximum hop count that then calculates message transmissions between source MEP shown in Figure 1 and the purpose MEP is 3 (256 deduct 253), and the number that comprises the node device N of purpose MEP between source MEP and the purpose MEP is 2; Report purpose MEP to follow the trail of echo message to network management system simultaneously;

Source MEP sends two first loopback request messages successively, wherein the TTL in the one first loopback request message LSP label is 1, transmission sequence number is 65534, TTL in another first loopback request message LSP label is 2, transmission sequence number is 65533, therefore two first loopback request messages adopt production decline law setting successively, but also are not limited to this rule, also can be set to increase progressively successively etc.;

The one MIP receives the first loopback request message, resolve this first loopback request message, the operation that obtains according to the LSP searching label is Swap, if the ttl value of this first loopback request message is 1, then respond this first loopback request message, generate one first loopback response message, and it is corresponding with the transmission sequence number of this first loopback request message that the transmission sequence number of the first loopback response message is set, and is 65534; If the ttl value of this first loopback request message is 2, then carry out the label exchange, the ttl value of this first loopback request message is deducted 1 after, transmit to the 2nd MIP;

The 2nd MIP receives the first loopback request message that a MIP transmits, the operation that the analytic message form obtains according to the LSP searching label is Swap, if this moment, the ttl value of the first loopback request message was 1 o'clock, then respond this first loopback request message, generate one first loopback response message, and the transmission sequence number that the first loopback response message is set is corresponding with the transmission sequence number of this first loopback request message, is 65533;

Source MEP receives the first loopback response message, transmission sequence number in the first loopback response message and the local transmission sequence number of preserving are mated, if the first loopback response message that a MIP responds, the match is successful for 65534 transmission sequence number, reports a MIP link tracing echo message to network management system; If the first loopback response message that the 2nd MIP responds, the match is successful for 65533 transmission sequence number, reports the 2nd MIP link tracing echo message to network management system; If purpose MEP back message using, the match is successful for 65535 transmission sequence number, follows the trail of echo message to the network management system reporting links; If do not match, directly abandon the first loopback response message, report corresponding MIP not have response to network management system.

Do not receive the second loopback response message of sequence numbers match in the MEP predetermined time cycle of source, report purpose MEP to follow the trail of failure information to network management system, and the similar mode of employing and above-mentioned steps sends 254 first loopback request messages, if a MIP and the 2nd MIP link, equipment etc. are normal, then respond the first loopback response message of corresponding TTL=1 and TTL=2, all the other loopback request messages are dropped at link or purpose MEP, can not produce response; Source MEP receives to network management system and reports corresponding MIP echo message, if link, equipment etc. are undesired, then reports corresponding MIP not have response to network management system.

By above-mentioned mode, network management system can form the actual syntople information of specifying between MEP, the MIP according to the information that source MEP node reports, or the indication link failure, if certain MIP or MEP have fault, so just, can not receive corresponding echo message, promptly know where be out of order.

The specific embodiment of the invention also provides a kind of device of realizing that service link is followed the trail of on the other hand, is applied to multiprotocol label switching and transmits application MPLS-TP network, and described device comprises:

The node device detecting unit is used for detection messages when described first safeguards that end endpoint transmission to the second is safeguarded the end end points, safeguards that described first end end points and described second safeguards the number N of institute's transmission node equipment between the end end points; Packet sending unit, be used for safeguarding that to described second the end end points sends the first loopback request message, it is corresponding that the set life span value of the wherein said first loopback request message and the described first loopback request message transfer to the required jumping figure of M node device, and wherein M is smaller or equal to N;

The message receiving element, receive described M node device and respond the first loopback response message that the described first loopback request message is sent, report described first link information of safeguarding between end end points and described M the node device according to the described first loopback response message.

The described device of the specific embodiment of the invention can be applied to the source end MEP on LSP on the MPLS-TP network or the PW path, described node device detecting unit be used for detection messages transfer to second safeguard end end points institute transmission node equipment number N mode can for:

Construct the second loopback request message, the source address of specifying this second loopback request message is the address of source MEP, and destination address is the address of the purpose MEP of appointment;

The transmission sequence number that is provided with simultaneously in the second loopback request message is a fixed value A, as is 65535, as the sign that mails to MEP;

Life span (TTL) value that is provided with in LSP label or the PW label is 255, also the maximum life span value of promptly transmitting between source MEP and purpose MEP;

Setting receives the predetermined period of time of loopback response message LBR from purpose MEP;

When the correct second loopback response message that receives in the predetermined time cycle that purpose MEP sends, take out the ttl value in LSP in the second loopback response message or the PW label, deduct this ttl value by 256 and then obtain maximum hop count between source MEP and the purpose MEP, this maximum hop count deducts 1 described numerical value and is the number N that comprises the node device of purpose MEP between source MEP and the purpose MEP.

In addition, described packet sending unit source structure is N first loopback request message: the LBM (1), LBM (2), LBM (3) at least ..., LBM (N), wherein the set life span value of each first loopback request message transfers to the first loopback request message that wherein the required jumping figure of a node device is corresponding, and the set life span of each first loopback request message is worth inequality, as the life span value of LBM (1) is set, make the life span of LBM (1) corresponding, can transfer to first node device with the jumping figure that transfers to first node device; The life span value of LBM (2) is set, makes the life span of LBM (2) corresponding with the jumping figure that transfers to first node device; And the like, the respectively life span value of first loopback request message is set respectively.

In addition, each first loopback request message LBM (1), LBM (2), LBM (3) ..., among the LBM (N), one specific transmission sequence number is set respectively, and those specific transmission sequence numbers are different from source MEP employed transmission sequence number A when purpose MEP sends the second loopback request message, best, each specific transmission sequence number is followed certain rule, be LBM (1) as the ordering of the first loopback request message, LBM (2), LBM (3) ..., during LBM (N), the transmission sequence number of each first loopback request message can adopt the rule of successively decreasing successively or progressively increasing to set, and is corresponding with ttl value.

Adopt above-mentioned structure and mode, node device between source MEP (MEP) and the purpose MEP (the 2nd MEP) is MIP or MEP, when the ttl value of the first loopback request message that is received is 1, then can respond this first loopback request message, return the first loopback response message to source MEP, source MEP is by resolving each first loopback response message, the transmission sequence number of each first loopback response message is mated with the transmission sequence number of being preserved, determine whether to receive the echo message of the node device between source MEP and the purpose MEP, when not receiving the response of a node device wherein, link failure is described, can indicate which the node device fault in the link, therefore form the actual syntople information between each node device.

The above only is a preferred implementation of the present invention; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the principle of the invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.

Claims (12)

1. a method that realizes that service link is followed the trail of is applied to multiprotocol label switching and transmits application MPLS-TP network, it is characterized in that described method comprises:

First safeguards end end-point detection message when described first safeguards that end endpoint transmission to the second is safeguarded the end end points, safeguards that described first end end points and described second safeguards the number N of institute's transmission node equipment between the end end points;

Described first safeguards that the end end points sends the first loopback request message to the described second maintenance end end points, it is corresponding that the set life span value of the wherein said first loopback request message and the described first loopback request message transfer to the required time of M node device, and wherein M is smaller or equal to N;

Described first safeguards that the end end points receives described M node device and responds the first loopback response message that the described first loopback request message is sent, and reports described first link information of safeguarding between end end points and described M the node device according to the described first loopback response message.

2. the method for claim 1, it is characterized in that, safeguard that described first the end end points sends in the step of the first loopback request message to the described second maintenance end end points, described first safeguards that the end end points sends N described first loopback request message at least, and the life span of each described first loopback request message value is inequality.

3. method as claimed in claim 1 or 2, it is characterized in that, described method is applied on the label switching path LSP and virtual link PW in the MPLS-TP network, and the described first loopback request message of wherein said life span value representation can transmit the number of the node device of process before abandoning.

4. the method for claim 1, it is characterized in that, when the described first maintenance end end-point detection message is held end points from described first maintenance end endpoint transmission to the second maintenance, safeguard that described first holding end points and described second to safeguard holds the step of the number N of institute's transmission node equipment between the end points specifically to comprise:

Described first safeguards that the end end points sends one second loopback request message to the described second maintenance end end points;

Described first safeguards that the end end points receives described second and safeguards the second loopback response message of holding end points to respond described second loopback request message transmission, according to the described second loopback response message, calculate the described second loopback request message when described first safeguards that the end endpoint transmission is safeguarded the end end points to described second, safeguard that described first end end points and described second safeguards the number N of institute's transmission node equipment between the end end points.

5. method as claimed in claim 4 is characterized in that, described first safeguards that the end end points specifically comprises to the step that the described second maintenance end end points sends one second loopback request message:

Described first safeguards that it is the address of the described first maintenance end end points that the end end points is specified the source address of the described second loopback request message, and destination address is the address of the described second maintenance end end points;

Described first safeguards that the transmission sequence number that the end end points is provided with in the described second loopback request message is a predetermined value, and the life span value that the described second loopback request message is set simultaneously is a maximum;

Described first safeguards that the setting of end end points receives the predetermined period of time of the described second loopback response message from the described second maintenance end end points;

Described first safeguards the end end points according to described second address of safeguarding the end end points, and the outlet of searching the described second loopback request message sends the described second loopback request message.

6. method as claimed in claim 4, it is characterized in that, described according to the described second loopback response message, calculate the described second loopback request message when described first safeguards that the end endpoint transmission is safeguarded the end end points to described second, safeguard that described first end end points and described second safeguards that the step of the number N of institute's transmission node equipment between the end end points specifically comprises:

Described first safeguards that the end end points obtains the life span value that is write down from the described second loopback response message, described first safeguards that the maximum life span value of being transmitted between end end points and the described second maintenance end end points deducts the life span value that is write down, obtain the described second loopback request message and safeguard the maximum hop count value of transmitting between end end points and the described second maintenance end end points described first, wherein said maximum hop count value deducts 1 value, equal the described second loopback request message when described first safeguards that the end endpoint transmission is safeguarded the end end points to described second, safeguard that described first end end points and described second safeguards the number N of institute's transmission node equipment between the end end points.

7. method as claimed in claim 5 is characterized in that, described first safeguards that the end end points also comprises after described second safeguards the step of holding end points to send one second loopback request message:

Described first safeguards that the end end points does not receive the described second loopback response message in described predetermined period of time, and then direct number N with the described second loopback request message institute transmission node equipment is set at 254.

8. method as claimed in claim 2 is characterized in that, described first safeguards that the end end points sends in the step of N the described first loopback request message at least, and the life span value of setting the described second loopback request message is the wherein integer in 1 to N.

9. the method for claim 1 is characterized in that, described first safeguards that the end end points after described second safeguards that the end end points sends the step of the first loopback request message, also comprises:

Described first safeguards that the node device between end end points and the described second maintenance end end points receives the described first loopback request message, and carries out following steps:

Step 1, described node device inquiry tag record sheet judges that when described node device was intermediate node, then execution in step two, judges that when described node device was tail node, then execution in step three;

Step 2, described node device judge whether the described life span value that is write down in the described first loopback request message is 1, if 1, then execution in step three, if be not 1, then execution in step four;

When step 3, described node device are configured to safeguard the end end points or safeguard the end intermediate point, then generate the described first loopback response message; When described node device is not configured to safeguard the end end points or safeguards the end intermediate point, then abandon the described first loopback request message;

Step 4, described node device subtracts one with the described life span value of the described first loopback request message, sends the described first loopback request message along the service message direction afterwards.

10. method as claimed in claim 9, it is characterized in that, in described step 3, the step of the described first loopback response message of described generation: the transmission sequence number that described node device is provided with the described first loopback response message is identical with the transmission sequence number of the described first loopback request message that is received, and the life span value of the described first loopback response message is set to 255 simultaneously.

11. the method for claim 1 is characterized in that, described first safeguards that the end end points after described second safeguards that the end end points sends the step of the first loopback request message, also comprises:

Described first safeguards that the node device between end end points and the described second maintenance end end points receives the described first loopback response message, and carries out following steps:

Steps A, described node device inquiry tag record sheet is judged when described node device is intermediate node, then execution in step B judges when described node device is tail node, then execution in step C;

Step B, described node device subtracts one with the described life span value in the described first loopback response message, sends the described first loopback response message along the service message direction afterwards;

Step C, described node device mates transmission sequence number in the described first loopback response message and the local transmission sequence number of preserving, and judges whether success of coupling, if the match is successful, execution in step D then; If coupling is unsuccessful, then execution in step E;

Step D, described node device reporting links tracked information;

Step e, described node device directly abandon the described first loopback response message.

12. a device of realizing that service link is followed the trail of is applied to multiprotocol label switching and transmits application MPLS-TP network, it is characterized in that described device comprises:

The node device detecting unit is used for detection messages when described first safeguards that end endpoint transmission to the second is safeguarded the end end points, safeguards that described first end end points and described second safeguards the number N of institute's transmission node equipment between the end end points;

Packet sending unit, be used for safeguarding that to described second the end end points sends the first loopback request message, it is corresponding that the set life span value of the wherein said first loopback request message and the described first loopback request message transfer to the required time of M node device, and wherein M is smaller or equal to N;

The message receiving element, receive described M node device and respond the first loopback response message that the described first loopback request message is sent, report described first link information of safeguarding between end end points and described M the node device according to the described first loopback response message.

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