CN101611393A - The performance monitoring of pseudo wire emulation - Google Patents

Abstract

A kind of system can transmit the announcement label mapping message to the network equipment, and this announcement label mapping message request is set up Active Performance and monitored (APM) control channel.And this system can handle the answer label mapping message that sends from the network equipment in response.The pseudo-line that this system can set up the APM control channel and be associated with this APM control channel.

Description

The performance monitoring of pseudo wire emulation

Technical field

Leave over network (legacy network) system, such as network system based on frame relay or ATM(Asynchronous Transfer Mode), can communicate described packet switching network such as Internet Protocol (IP) exchange network or multiprotocol label switching (mpls) network by pseudo wire emulation (PWE) and packet switching network (PSN).Have necessary management and control PWE and related pseudo-line.

Description of drawings

Fig. 1 shows and can realize that wherein Active Performance monitors the network of (APM);

Fig. 2 is the block diagram of provider edge (PE) router and provider's exchange (PS) router of Fig. 1;

Fig. 3 is the exemplary functional block diagram of the assembly that is included in the PE of Fig. 1 and the PS router or realized by PE and the PS router of Fig. 1;

Fig. 4 is the exemplary functional block diagram of the forwarding logic of Fig. 3;

Fig. 5 A illustrates the example packet of the pe router that can arrive Fig. 1;

Fig. 5 B illustrates the example packet with the MPLS header between two headers that are inserted in Fig. 5 A;

Fig. 5 C illustrates the exemplary configurations of the MPLS header of Fig. 5 B;

Fig. 6 illustrates the exemplary functional block diagram of the logical routing of Fig. 3;

Fig. 7 has described the exemplary expression of some assemblies of pseudo-line and Fig. 1;

Fig. 8 shows the exemplary functional block diagram of the pseudo-line logic of Fig. 6;

Fig. 9 A shows the example format of tag distribution protocol (LDP) message;

Fig. 9 B has described to be used for the example format of pressure/optional parameter field of Fig. 9 A;

Fig. 9 C shows the example format of forwarding equivalence class (FEC) type lengths values (tlv) that is used for Fig. 9 B;

Figure 10 A and Figure 10 B show the exemplary configurations of pseudo-line (PW) ID FEC element and general PW IDFEC element respectively;

Figure 10 C shows the exemplary configurations of the interface parameters TLV of Figure 10 B;

Figure 11 A illustrates the example virtual circuit control of the LDP message that is used for setting up pseudo-line and confirms (VCCV) parameter field;

Figure 11 B shows the exemplary arrangement of control word in the control messages;

Figure 11 C shows the exemplary configurations of the PW associated channel header of Figure 11 B;

Figure 12 shows and is used for the example process that the APM control channel is set up at pseudo-line (PE) emulation;

Figure 13 shows the example process that is used to write LDP message, and this LDP message can be delivered to another pe router from a pe router with PWE and APM ability; And

Figure 14 illustrates and is used to use the APM control channel to exchange the example process of APM message.

Embodiment

Following detailed is with reference to accompanying drawing.Same reference numerals in different accompanying drawings can be represented identical or similar element.(BFD) can be illustrated in forward direction and the inverse direction and to monitor that route or data routing are to find fault or unusual as term used herein " two-way forwarding detection ".

The Active Performance that implementation as described herein can relate to the performance that is used to monitor pseudo-line monitors the foundation and/or the use of (APM) control channel.

Fig. 1 illustrates the network 100 that can realize the APM control channel therein that is in data link layer level (that is the second layer in the OSI(Open Systems Interconnection) network model).Network 100 can comprise leaves over network 102 and 104, IP/MPLS network 106 and attachment circuit 108 and 110.

Leave over network 102 and 104 can comprise be used to provide such as, for example, the equipment of the local network services of Ethernet, ATM, frame relay and/or Time Division Multiplexing and so on and/or system.As further shown in Figure 1, leave over network 102 and 104 and can comprise client edge (CE) router one 12 and 114. Ce router 112 and 114 can comprise the router that is positioned at customer rs premise, and can provide and enter the inlet of leaving over network 102 and 104 and withdraw from the outlet of leaving over network 102 and 104.

IP/MPLS network 106 can comprise equipment and/or the system that Fast Packet Switch is provided.As shown in fig. 1, IP/MPLS network 106 can comprise provider edge (PE) router one 16 and 118 and provider exchange (PS) router one 20 and 122.Pe router 116 and 118 can comprise can provide the inlet that enters and withdraw from IP/MPLS network 106 and/or the router of outlet.PS router one 20 and 122 can comprise to be accepted the IP/MPLS grouping and they is routed to the router of their destination equipment.

Attachment circuit 108 and 110 can comprise and be used for and will leave over the combination of hardware, software and/or hardware and software that network 102 and 104 is docked with IP/MPLS network 106.Go to and can pass attachment circuit 108 and 110 to move into and to shift out IP/MPLS network 106 from the grouping of leaving over network 102 and 104.

Can be forwarded to another equipment (for example, ce router 114) of leaving in the network 104 via the equipment (for example, ce router 112) that IP/MLPS network 106 will divide into groups from leave over network 102.In order to transmit by attachment circuit 108 and 110 groupings that arrive, IP/MPLS network 106 can be set up the network path that is called as pseudo-line, and can be via this puppet circuit by grouping.

Pe router 116/118 can be set up pseudo-line and pass through this puppet circuit by grouping.In addition, pe router 116/118 can be by being provided with and using Active Performance to monitor that (APM) control channel monitors pseudo-line (that is, in the same channel of carrying client network business) in the band on one's own initiative.By using the APM control channel, can assess network traffic conditions, such as handling capacity, time delay (that is, postponing), packet loss, shake (that is, because the variation of grouping time of arrival that network congestion causes).

Fig. 2 illustrates the block diagram of pe router 116/118 and the PS router one 20/122 of Fig. 1, is hereinafter referred to as " PE/PS router one 16-122 ".Each of PE/PS router one 16-122 can comprise processor 202, storer 204, line interface 206 and 208, interconnection 210 and bus 212.

Processor 202 can comprise one or more processors, microprocessor, special IC (ASIC), field programmable gate array (FPGA) and/or the processing logic of optimizing with communicating by letter at networking.Processor 202 can be handled grouping and/or network path-related information.Storer 204 can comprise such as the static memory of ROM (read-only memory) (ROM), carry (onboard) buffer memory such as the dynamic storage and/or the plate of random-access memory (ram), is used to store data and machine readable instructions.Storer 204 can also comprise memory device, such as floppy disk, CD ROM, CD read/write (R/W) dish and/or flash memory, and the memory device of other type.Line interface 206 and 208 can comprise and be used for receiving the equipment that enters grouping and be used for dividing into groups to the network emission from network.Interconnection 210 can comprise one or more switches or switching fabric, and this switch or switching fabric are used for the routing information based on grouping destination and storage, will enter grouping and be delivered to line interface 208 from line interface 206.Bus 212 can comprise such path: the communication between components of each of this path permission PE/PS router one 16-122.

Fig. 3 be included in each of PE/PS router one 16-122 or by the exemplary functional block diagram of the assembly of each realization of PE/PS router one 16-122.As shown in the figure, PE/PS router one 16-122 can comprise buffer-manager 302, forwarding logic 304 and logical routing 306.Buffer-manager 302 can be provided for making the impact damper that enters packet queue.If grouping arrives simultaneously, then can be with one or more packet memory in impact damper, until the grouping of having handled and/or having launched higher priority.Forwarding logic 304 can comprise and being used for based on hardware and/or the software of routing iinformation with the suitable output port on direct packets line interface 206 or 208 one.Logical routing 306 can comprise and be used for communicating to collect routing iinformation and routing iinformation to be stored in the hardware and/or the software of tag information base (LIB) with other router.

Fig. 4 is the exemplary functional block diagram of forwarding logic 304.As shown in the figure, forwarding logic 304 can comprise MPLS logic 402, tag forwarding information base (LFIB) 404 and LIB 406.MPLS logic 402 can comprise and is used for header that the header information of being stored based on LFIB 404 and LIB 406 and the inspection of path/routing iinformation enter grouping and hardware and/or the software that is used for sending to suitable output port grouping.LFIB 404 and LIB 406 can comprise the form and/or the database of the network path that is called as label switched path (LSP), and/or routing iinformation.LFIB 404 can comprise the frequent part of using of LIB 406, and can be littler than LIB 406.

MPLS logic 402 can be to operate as pe router 116, pe router 118, PS router one 20 or PS router one 22 according to its host router, carries out different routing programs.According to entering grouping and its network configuration, host router may be operated as pe router 116 or PS router one 20 in different examples.If host router is operated as pe router 116, then as following, MPLS logic 402 can become the MPLS grouping with the packet switched that enters network 106 by add the MPLS header to grouping.On the contrary, MPLS logic 402 can be changed 106 the MPLS grouping of exitting network by the MPLS header of peeling off MPLS grouping.

Fig. 5 A illustrates the example packet 500 that can arrive pe router 116.As shown in the figure, grouping 500 can comprise L2 header 502 (that is the packet header of osi layer level 2) and L3 header 504 (that is the packet header of osi layer level 3).When receiving grouping 500 the time, MPLS logic 402 can be included into class with grouping 500, can be based on this classification together with come together to determine to divide into groups 500 the next destination of canned data among LFIB 404 and/or the LIB 406.In addition, illustrated as Fig. 5 B, MPLS logic 402 can be inserted MPLS header 506 between L2 header 502 and L3 header 504, and can be via line interface 206 or 208 (Fig. 2) emission grouping 500.At pe router 118 places, shown in Fig. 5 B, if divide into groups 500 to arrive to withdraw from IP/MPLS network 106, then MPLS logic 402 can be peeled off MPLS header 506, causes the grouping 500 shown in Fig. 5 A, and can send grouping 500 to network 104.

If host router is as PS router one 20 operation, then MPLS logic 402 can be on the MPLS of received grouping header 506 executable operations, and can send (that is route) these groupings based on MPLS header 506.This operation can comprise creating another MPLS header and being right after MPLS header 506 inserts this another MPLS header, changes MPLS header 506 and/or remove MPLS header 506 with another MPLS header.

Fig. 5 C illustrates the structure of the MPLS header 506 that can comprise label 508.In PS router one 20, label 508 can accomplish that index among LFIB 404 or the LIB406 is to determine operation (that is, create and insert the MPLS header, change the MPLS header or remove the MPLS header with another MPLS header) and next destination by MPLS logic 402 usefulness.Because (for example, at specific PS router one 20 or 122 places) can carry out a lot of operations in this grouping during grouping is through IP/MPLS network 106, so grouping may have the MPLS header 506 more than.Yet, when grouping deviated from network 106, can remove the MPLS header.

Fig. 6 shows the exemplary functional block diagram of the logical routing 306 of Fig. 3.As shown in the figure, logical routing 306 can comprise tag distribution protocol (LDP) logic 602, pseudo-line logic 604 and other logic 606.

LDP logic 602 can comprise hardware and/or the software that is used for sharing with other PE that comprises the LDP logic and PS router label.As described in more detail below, pseudo-line logic 604 can comprise hardware and/or the software that is used to set up pseudo-line.Other logic 606 can comprise the hardware/software that is used to realize other ability of being associated with logical routing 306, and other ability is sent such as quality-of-service packet.

LDP logic 602 can be executed specific collection of programs (that is LDP agreement) and be used to exchange message (for example, LDP message) about label.By the exchange of LDP message, the LIB of each router in the IP/MPLS network 106 can be filled route and label information, and the PE of participation and PS router can be observed this route and label information.

Briefly, LDP message can comprise with forwarding equivalence class (FEC) with each FEC the relevant information of label of be associated (that is binding).At pe router 116 places, for example, each FEC can represent the class that can be included into from the grouping of external network.By sending group classifying with charge free grouping in FEC and based on the label that is associated with FEC, IP/MPLS network 106 can provide along with the adjustable route service of Packet Service that increases.

If FEC and label information that LDP logic 602 usefulness in the pe router 116 are propagated from pe router 118 are filled its LIB 406, then for the grouping that arrives pe routers 116 from attachment circuit 108, can determine from pe router 116 to pe router 118 label switched path (LSP).Similarly, if LDP logic 602 usefulness in the pe router 118 are filled its LIB 406 from the FEC and the label information of pe router 116, then for the grouping that arrives pe routers 118 from attachment circuit 110, can determine from pe router 116 to pe router 118 LSP.Each of two LSP between pe router 116 and the pe router 118 can be operated as MPLS tunnel (for example, such path: the inlet point of MPLS header number in this path in this path in the grouping can be identical with the exit point place).

Get back to Fig. 6, if logical routing 306 receives or sends and the FEC and/or the relevant information of label that are used to leave over network packet, then pseudo-line logic 604 can be called LDP logic 602.More specifically, pseudo-line logic 604 can be created or exchange and FEC and/or be tied to the relevant LDP message of label of this FEC, this FEC with leave over network packet and be associated.The result of LDP message in return, pseudo-line logic 604 can be set up two LSP on MPLS tunnel described above.These two LSP can form bi-directional pseudo-wire, and wherein each LSP can be unidirectional, and can move on the direction opposite with another LSP.

Fig. 7 has described the exemplary expression of some assemblies of pseudo-line 702 and Fig. 1.As shown in Figure 7, pseudo-line 702 can extend to attachment circuit 110 from attachment circuit 108, and can depend on the MPLS tunnel 704 and 706 below extending between pe router 116/118.If be established, then pseudo-line 702 can transmit the grouping that flows into the pe router 116 from attachment circuit 108.

If grouping arrives pe router 116, then pe router 116 can become pseudo-line grouping with packet encapsulation (that is conversion) by pseudo-report from a liner head being added to grouping.Pe router 116 can be the MPLS grouping with packet encapsulation by adding the MPLS header, and can should divide into groups towards the destination of this grouping route by MPLS tunnel 704.If be grouped in 704 appearance from the MPLS tunnel of pe router 118 places, then pe router 118 can come deblocking (that is, changing back) grouping by removing MPLS header and pseudo-report from a liner head.Based on the information that is included in the pseudo-report from a liner head, can with or can this grouping be transmitted into attachment circuit 110.

Fig. 8 has described the exemplary functional block diagram of pseudo-line logic 604.As shown in the figure, pseudo-line logic 604 can comprise signaling logic 802, virtual circuit is connective confirms that (VCCV) logic 804, Active Performance monitor (APM) logic 806 and/or control messages processing logic 808.As following, signaling logic 802 can comprise and be used for being used for exchanging LDP message to set up and to keep the hardware and/or the software of pseudo-line by making of LDP logic 602 and control messages.VCCV logic 804 can comprise hardware and/or the software that is used to create and use the control channel that is associated with pseudo-line.APM logic 806 can comprise hardware and/or the software that is used to create and use the APM control channel that is associated with pseudo-line.Control messages processing logic 808 can comprise hardware and/or the software that is used to transmit control message and is used to handle the control messages that can receive by pseudo-line.In different implementations, can arrange discriminatively or constitutional diagram 8 in assembly (for example, APM logic 806 can be included in the VCCV logic 804).

Signaling logic 802 can be by carrying out the attribute that various functions allow the sign of pseudo-line and can signal pseudo-line.This function can comprise, for example, exchanges LDP message with PS and pe router 116-122.The LDP message semantic definition with leave over the FEC that network packet is associated and be tied to the label of this FEC.

Fig. 9 A shows the example format of the LDP message 900 that can be generated by signaling logic 802.In general, LDP header (not shown) can be before one or more LDP message 900, and each LDP message 900 can be taked the type lengths values (tlv) form.As shown in Fig. 9 A, LDP message 900 can comprise various field, such as unknown field 902, message type field 904, message length field 906, message id field 908 and pressure/optional parameter field 910.If unknown field 902 can specify LDP message 900 to have UNKNOWN TYPE, then whether return answer to LDP message 900.For example, if unknown field 902 is " 1 ", if when then not picking out value in the message type field 904, then can ignore LDP message 900 at the receiving router place.Message type field 904 can be indicated LDP type of message (for example, keeping alive messages, address message, label mapping message etc.).Message length field 906 can Indication message id field 908 and pressure/optional parameter field 910 with eight hytes cumulative length that is unit.Message id field 908 can comprise the value that is used to identify LDP message 900.Pressure/optional parameter field 910 can comprise may need and/or the optional parameter of value for certain message types 904.

Fig. 9 B shows and is used to force/example format of optional parameter field 910.As shown in the figure, mandatory parameters field 910 can comprise can provide classes of packets (that is FEC-TLV field 912 of FEC) tabulating.Fig. 9 C shows the example format that is used for FEC-TLV field 912.FEC-TLV field 912 can comprise various field (for example, zero flag field 914, FEC field 916, length field 918, FEC element field 920 etc.).Zero flag field 914 and FEC field 916 can be set to constant (for example, being respectively " 0 " and " 0x0100 ").Length field 918 can comprise the value about the length of FEC element field 920.

In the LDP message that comprises about the information of pseudo-line, FEC element field 920 can comprise, for example, and PW ID FEC element, general PW ID FEC element etc.Figure 10 A and Figure 10 B illustrate the exemplary configurations of PW ID FEC element 1002 and general PW ID FEC element 1018 respectively.

As shown in Figure 10 A, PW ID FEC element 1002 can comprise PW id 1004, C element 1006, PW Class1 008, PW message length 1010, group ID 1012, PW ID 1014 and/or the sub-TLV 1016 of interface parameters.PW id 1004 can identify PW ID FEC element 1002 and can be configured to constant value (for example, " 0x80 ").C element 1006 can specify whether there is the control word that is used for the control messages that can transmit by the pseudo-line that is associated with PW ID FEC element 1002.For the pseudo-line with APM control channel, C element 1006 can be arranged for indicating the value (for example, " 1 ") that has control word in APM message.

PW Class1 008 can be represented the type of pseudo-line.The example of PW Class1 008 can comprise " 0x0001 " that be used for frame relay, be used for " 0x0003 " of the transparent cell transmission of ATM, be used for " 0x0005 " of Ethernet etc.PW message length 1010 can be specified the cumulative length of PW ID 1014 and the sub-TLV 1016 of interface parameters.Group ID 1012 can specify the value of any 32 bits of one group of pseudo-line of expression.PW ID 1014 can identify particular pseudowire.The sub-TLV 1016 of interface parameters can be used to provide the information specific to interface, such as the characteristic of attachment circuit (for example, attachment circuit 108 and 110).

As shown in Figure 10 B, general PW ID FEC element 1018 can comprise general PW id1020, C element 1022, PW Class1 024, PW message length 1026, attachment circuit (AC) information 1028 and/or interface parameters TLV 1030.General PW id 1020 can identify general PWID FEC element 1018 and can be configured to constant value (for example, " 0x18 ").As mentioned above, C element 1022 and PW Class1 024 can be specified the information identical with C element 1006 and PW Class1 008.PW message length 1026 can be specified the length of attachment circuit (AC) information 1028.Attachment circuit information 1028 can be specified and local and remote attachment circuit, such as attachment circuit 108 address information relevant with 110.Be similar to the sub-TLV1016 of interface parameters, interface parameters TLV 1030 can be used so that the parameter specific to interface to be provided.

Figure 10 C illustrates the exemplary configurations of interface parameters TLV 1030.As shown in the figure, interface parameters TLV 1030 can comprise nil segment 1032, PW interface parameters TLV 1034, length 1036 and/or the sub-TLV 1038 of interface parameters.Nil segment 1032 and PW interface parameters TLV1034 can be set to constant (for example, being respectively " 0x00 " and " 0x096B ").Length 1036 can the sub-TLV 1038 of specified interface parameter length.As above described, can use among the sub-TLV 1038 of interface parameters each for similar purpose at the sub-TLV of interface parameters 1016.

Turn back to Fig. 8, if signaling logic 802 and its peers include both exchange LDP message, then VCCV logic 804 can be by being arranged as the VCCV parameter field the TLV 1016 of interface parameters (Figure 10 A) in the PW ID FEC element 1002 and/or setting up the control channel that is used for pseudo-line in the sub-TLV 1038 of interface parameters (Figure 10 C).

Figure 11 A illustrates the example format of VCCV parameter field 1102.As shown in the figure, VCCV parameter field 1102 can comprise Class1 104, length 1106, control channel (CC) Class1 108 and connective affirmation (CV) Class1 110.Class1 104 can identify VCCV parameter field 1102, and can be set to eight octet value (for example, " 0x0c ").Length 1106 can provide the length (for example, 4 bytes) of VCCV parameter field 1102, and can be set to constant value (for example, " 0x04 ").

CC Class1 108 can carry 8 bit fields can receive the professional control channel (a plurality of) of control by it with the indication router type.In 8 bits of CC Class1 108 fields, each that can use bit " 0-2 " is assigned one (for example, as being distributed by internet assigned number authority (IANA)) in 3 control channel types.CV Class1 110 can comprise bit field, is used to verify the type of the control messages of the connectedness between the pseudo-line endpoints with indication.For example, CV Class1 110 can indicate control messages can be Internet Control Message Protocol (ICMP) Ping (promptly, echo request based on ICMP), LSP Ping (promptly, echo request by LSP) or two-way forwarding detect (BFD) signal, it can represent to be used to monitor continuously that route and data routing are to find the message of fault in forward direction and inverse direction.

Turn back to Fig. 8, if constructed pseudo-line and related control channel, then VCCV logic 804 can send and/or receiving control message by this control channel.This control channel can carry in the type of message indicated in the CV Class1 110 of VCCV parameter field 1102 at the whole duration of existence of control channel.If emission control message, then VCCV logic 804 can generate the mark that is called as control word, if to have assigned band inner control channel by CC Class1 108 fields during the foundation of control channel, then control messages and other pseudo-line grouping is differentiated.

Figure 11 B shows the exemplary arrangement of control word in the control messages 1112.As shown in the figure, control word can be a PW associated channel header 1116, and can be between MPLS label stack 1120 that comprises MPLS header 1118 and L3 header 1114.Figure 11 C shows the exemplary configurations of PW associated channel header 1116.As shown in the figure, PW associated channel header 1116 can comprise nibble (nibble) 1122, version 1124, reservation 1126 and channel type 1128.Nibble 1122 can be indicated the channel that is associated with pseudo-line, and can the value of being set to (for example, " 0x01 ").Version 1124 and to reserve 1126 can be constant and can the value of being set to (for example, " 0 ").Channel type 1128 can be in three values one (for example, " 0x0021 " be used to indicate internet protocol version four (IPv4), " 0x0056 " to be used for IPv 6 (IPv6) or " 0x0006 " is used for the BFD channel that carrying does not have the grouping of Internet Protocol (IP)/User Datagram Protoco (UDP) (UDP) header).

Turn back to Fig. 8, if signaling logic 802 and its peers include both exchange LDP message, then APM logic 806 can by VCCV parameter field 1102 (Figure 11 A) is write among PW ID FEC element 1002 (Figure 10 A) the sub-TLV 1016 of interface parameters (Figure 10 A) and/or in the sub-TLV 1038 of interface parameters (Figure 10 C) ask and be provided with the Active Performance monitoring channel.

More specifically, APM logic 806 can be write bit value " 1 " for the APM bit in the CC Class1 108 (for example, the bit " 6 " in the bit " 3-7 ").Can register or can not register this to IANA to IANA can be as the bit in the CC Class1 108 of APM bit, such as the bit in the CC Class1 108 " 0-2 ".In addition, APM logic 806 can be indicated the APM control channel that can pass through to be set up to exchange Active Performance in CV Class1 110 and be monitored message.

In case constructed pseudo-line and related APM control channel, APM logic 806 just can send, receive and/or handle APM message by this APM control channel, to monitor the performance of related pseudo-line on one's own initiative.APM message can be carried and can be generated at the pe router place to obtain the test service such as the network performance tolerance of handling capacity, time delay, packet loss and shake.The same with the VCCV control messages, each of APM message can be carried the PW associated channel header as its control word.Yet, form contrast with the channel type 1128 of the PW associated channel header 1116 that is used for the VCCV control messages, as indicated in the CV Class1 110 in the LDP message of exchange during the APM control channel is set up, the channel type 1128 that is used for the PW associated channel header 1116 of APM message can comprise the value of reflection Active Performance function for monitoring.

Implementation described above is provided for the exemplary active performance surveillance of pseudo-line, it comprises system element, such as PE/PS router one 16-122, forwarding logic 304, logical routing 306, pseudo-line logic 604, signaling logic 802, VCCV logic 804 and APM logic 806, and related message structure and form.Figure 12-Figure 14 has described can be by the example process of one or more execution of these system elements.

Figure 12 shows the example process 1200 that is used to set up the APM control channel that is used for pseudo-line.Process 1200 can begin (frame 1202) to obtain the parameter relevant with attachment circuit (for example, attachment circuit 108 and 110) with long-range pe router (for example, pe router 118).In an implementation, can obtain this parameter from network manager or user.In another implementation, can obtain this parameter by dynamic auto discovery procedure.

Can obtain APM and select (frame 1204).In an implementation, can carry out the selection that is obtained by user, keeper and/or by another equipment.In other implementation, APM can selected conduct be used for the default control channel of any pseudo-line that can be established.

As further illustrated in Figure 12, can initiate label distribution (frame 1206).In an implementation, for example, initiating label distribution can comprise: initiate and stop the LDP session, send hello messages, carry out other LDP initialize routine etc.Label distribution can comprise downstream autonomous mode and free label retention mode.In the autonomous mode of downstream, under situation not, label and the FEC that is associated with label can be transmitted into downstream router from router from the requirement of downstream router.In label retention mode, can send out the receiving router of the jumping distance between router and the receiving router and keep by being independent of the source about the information of FEC and the label that is associated with FEC.

Process 1200 can also comprise announcement PWE and APM ability (frame 1208).In an implementation, in order to announce PWE and APM ability, can generate LDP message, and send this LDP message from the pe router of initiating PWE such as label mapping message.Figure 13 illustrates the example process 1300 that is used to write LDP message, and this LDP message is delivered to another pe router with PWE and APM ability from a pe router.

As shown in Figure 13, process 1300 can comprise: signal the bit value of being set to (frame 1302) in the CV Class1 110 in APM and VCCV parameter 1102 fields in CC Class1 108.In an implementation, for example, APM bit (that is the predetermined bit between the bit " 3-7 " in CC Class1 108) can indicate the pe router of launching to support APM.Bit in the CV Class1 110 can be indicated the type (that is APM message) of the message that can pass through the exchange of APM control channel.

Can use VCCV parameter field 1102 to form the sub-TLV 1038 of interface parameters (frame 1304).Can use the sub-TLV 1038 of interface parameters to form general PW ID FEC element 1018 or PW ID FEC element 1002 (frame 1306).In an implementation, in forming general PW ID FEC element 1018, the information about attachment circuit that obtains at frame 1202 can be used as attachment circuit information 1028 and is merged in.

As further shown in Figure 13, can use general PW ID FEC 1018 or PW IDFEC 1002 to finish LDP message (frame 1308).For example, in an implementation,, can use general PW ID FEC 1018 or PW IDFEC 1002 to finish LDP message as above described in conjunction with Fig. 9 A-9C.Process 1300 can also comprise transmission LDP message (frame 1310).The LDP message that can be sent out can comprise, for example, and notification message, label request message, label release message, label mapping message etc.

Turn back to Figure 12, process 1200 can comprise receiving answers LDP message (frame 1210).In an implementation, answer LDP message and can be derived from the pe router that sends the original tag mapping message to it.If the information that the pe router at pseudo-line other end place is failed to verify in the label mapping message and comprised, then answering LDP message can be label release message.Otherwise answering LDP message can be another label mapping message.If answering LDP message is label mapping message, then CV Class1 110 fields can be indicated and be supported Active Performance to monitor.

Can upgrade or end-tag distribution (frame 1212).In an implementation, according to LDP, described end can relate to initiation and termination LDP session, send extra LDP message etc.If pe router is finished the switch label mapping message and upgraded their LIB, then two of message transfer unidirectional LSP can be used as bi-directional pseudo-wire in the opposite direction.In addition, the APM control channel that is associated with pseudo-line is available.

Figure 14 illustrates the example process 1400 that is used for by APM control channel exchange APM message.As shown in the figure, process 1400 can be to obtain that the request of Active Performance test is begun (frame 1402).In an implementation, this request can be derived from the keeper at user and/or pe router place or be derived from remote equipment or be derived from leaves over the network equipment.For the purpose of testing characteristics of network, can prepare APM message (frame 1404).

APM message can be encapsulated as has control word (frame 1406).More specifically, can be by adding PW header (that is the MPLS header of indication PW) and carrying out encapsulation by inserting control word (that is, the PW associated channel header 1116).Discuss and decide by the terminal pe router during setting up according to pseudo-line, control word can comprise the channel type 1128 of indication Active Performance supervision.

As further shown in Figure 14, APM message can be encapsulated as has the MPLS header (frame 1408), and this APM message can be sent out (frame 1410).In an implementation, the APM message of encapsulation can arrive the destination pe router, and it can respond APM message by answering APM message.The pe router that sends original APM message can receive answers APM message, and can determine pseudo-dimension amount based on answering characteristic (for example, answer APM message and arrive required time quantum), such as handling capacity, time delay, packet loss or shake.In this mode, use the Active Performance of band inner control channel to monitor that continuous (or discontinuous) that can allow PW monitors.

In conjunction with above in conjunction with the described implementation of Fig. 1,7,9A-9C, 10A-10C and 11A-11C, more than set up and use the example process of APM control channel to be further specified in conjunction with Figure 12-14 being used to of describing by following example.Suppose that leaving over network 102 and 104 for two is the ethernet networks that can set up communication channel by the pe router in the IP/MPLS network 106 116 and 118.In addition, suppose that pe router 116 and 118 can adopt the communication media of pseudo-line as them.

At pe router 116 places, can obtain the parameter relevant by automatic discovery procedure with long-range pe router 118 and its attachment circuit 110.In addition, pe router 116 can obtain to instruct the APM control channel that is used for testing on one's own initiative and monitoring pseudo-line with foundation.

If pe router 116 has obtained parameter, then pe router 116 can initiate label distribution, can begin and close on the LDP session of PS router one 20 and can send label mapping message.Label mapping message can comprise the information with illustrated form among Fig. 9 A-9C, 10A-10C and the 11A.PS router one 20 can be forwarded to label mapping message another PS router successively.PS router in the IP/MPLS network 106 can continue to propagate label mapping message and receive label mapping message until pe router 118.

If pe router 118 receives label mapping message, then pe router 118 can be verified the content of label mapping message.When successfully verifying, the label mapping message that pe router 118 can upgrade its LIB and can send himself is as answer.This answer can comprise the value of the CC Class1 108 of signaling the APM control channel, as doing from the label mapping message of pe router 116.The value of CV Class1 110 can indicate APM message to be carried by the APM control channel.

If checking is unsuccessful, then pe router 118 can send label release message.When receiving answer from pe router, pe router 116 can upgrade the LIB of himself.By the exchange of previous label mapping message, can set up bi-directional pseudo-wire.

Be at pseudo-line under the situation of appropriate location, pe router 116 can receive request to monitor pseudo-line from the network manager.Pe router 116 can be write APM message, and can encapsulate this message.This encapsulation can relate to inserts control word (for example, the selected control messages type that is used among the control messages type in the CV Class1 110 of answering in the label mapping message is provided with channel type 1128) and additional PW header.The message of this encapsulation can further be encapsulated as has the MPLS header.According to the content of APM message, pe router 116 can send the APM message that obtains to pe router 118, and this can respond APM message.Pe router 116 can continue to send extra APM message and be terminated until performance monitoring.

Above example has illustrated how the APM control channel can be established and how be used to send APM message by pseudo-line in the band.In addition, aforementioned description to implementation provides explanation, but and is not intended to limit or implementation is limited to disclosed exact form.In view of above instruction modifications and variations are possible, perhaps can from the practice of this instruction, obtain.

For example, although Fig. 8 in signaling logic 802 shown in the pseudo-line logic 604, VCCV logic 804 and APM logic 806, in other implementation, signaling logic 802, VCCV logic 804 and APM logic 806 can have different functional classifications.For example, signaling logic 802 can comprise VCCV logic 804, and VCCV logic 804 in turn can comprise APM logic 806.

In addition, although at the illustrated process prescription of Figure 12-14 a series of action, can be modified at the order that moves described in other implementation.For example, can before frame 1202, carry out frame 1204.In addition, non-dependent acts can represent can executed in parallel action.For example, can executed in parallel frame 1202,1204 and 1206.In another example, can executed in parallel frame 1302,1304 and 1306.

It is evident that, can realize aspect as described herein with the different form of software, firmware and hardware in the implementation illustrated in many and the accompanying drawing.Be used to realize that the actual software code of these aspects or special-purpose control hardware do not limit the present invention.Therefore, under situation not, the operation and the behavior of these aspects have been described with reference to specific software code---should be appreciated that and can come design software and control hardware based on the description here to realize these aspects.

In addition, some part of these implementations has been described to carry out " logic " of one or more functions.This logic can comprise hardware, such as processor, special IC or field programmable gate array, and the combination of software or hardware and software.

It is key or basic that employed in this application any element, action or instruction should not be interpreted as implementation as described herein, and removing is far from it clearly describes.And as used herein, the item that does not add numeral-classifier compound is intended to comprise one or more.When only referring to one, use term " " or similar language.In addition, phrase " based on " be intended to mean " at least in part based on ", unless explicit state is arranged in addition.

Claims (24)

1. method comprises:

Transmit the announcement label mapping message to the network equipment, the request of described announcement label mapping message is set up Active Performance and is monitored control channel;

The answer label mapping message that processing response sends in described announcement label mapping message and from the described network equipment; And

The Active Performance of setting up pseudo-line and being associated with described pseudo-line monitors control channel.

2. method according to claim 1, wherein, described method further comprises:

Use described Active Performance to monitor that control channel monitors described pseudo-line on one's own initiative.

3. method according to claim 2 wherein, monitors that on one's own initiative described pseudo-line comprises:

Monitor that by described Active Performance control channel sends message to the described network equipment.

4. method according to claim 2 wherein, monitors that on one's own initiative described pseudo-line comprises at least one in the assessment the following:

Handling capacity, time delay, packet loss or shake.

5. method according to claim 1, wherein, transmit the announcement label mapping message to the network equipment and comprise:

Sign indicating number is included in virtual circuit in the described announcement label mapping message is connective confirms that the connectedness among the parameter field confirms in the type field.

6. method according to claim 1, wherein, handle the answer label mapping message and comprise:

Based on the value in the connectedness affirmation type field among the connective affirmation of the virtual circuit in the described answer label mapping message parameter field, determine whether the described network equipment supports Active Performance to monitor.

7. method according to claim 1, wherein, transmit the announcement label mapping message to the network equipment and comprise:

Sign indicating number is inserted in the connective control channel type field of confirming among the parameter field of virtual circuit in the described announcement label mapping message, sets up described Active Performance with request and monitor control channel.

8. method according to claim 1, wherein, handle the answer label mapping message and comprise:

Based on the value in the control channel type field among the connective affirmation of the virtual circuit in the described answer label mapping message parameter, determine whether the described network equipment supports described Active Performance to monitor control channel.

9. method according to claim 1 further comprises:

Generate Active Performance and monitor message; And

Monitor that by described Active Performance control channel sends described Active Performance and monitors message.

10. method according to claim 9 wherein, generates Active Performance and monitors that message comprises:

The channel type field is inserted in the control word, to have indicated the described Active Performance information relevant that monitored message bearing with performance test; And

Described control word is inserted into described Active Performance to be monitored in the message.

11. an equipment comprises:

Logic is used for:

Monitor control channel by sending a request message to remote equipment notice Active Performance with signal;

Monitor control channel based on the Active Performance of setting up pseudo-line from the response message of described remote equipment and being associated with described pseudo-line; And

Monitor that by described Active Performance control channel sends test post to described remote equipment and monitors described pseudo-line on one's own initiative.

12. equipment according to claim 11, wherein, described pseudo-line comprises that described Active Performance monitors control channel.

13. equipment according to claim 11, wherein, each of described test post comprises:

Control word, being used to indicate described message is that Active Performance monitors message.

14. equipment according to claim 11, wherein, described request message comprises:

In pseudo-line ID forwarding equivalence class type lengths values element or the general pseudo-line ID forwarding equivalence class type lengths values element at least one.

15. equipment according to claim 14, wherein, described request message comprises the forwarding equivalence class type lengths values.

16. equipment according to claim 14, wherein, described general pseudo-line ID forwarding equivalence class type lengths values element comprises:

Interface parameters subtype length value.

17. equipment according to claim 16, wherein, described interface parameters subtype length value comprises:

The connective affirmation of virtual circuit parameter field.

18. equipment according to claim 11, wherein, described response message comprises:

The control channel type field; And

Connective affirmation type field.

19. equipment according to claim 11 further comprises:

Ply-yarn drill, described ply-yarn drill sends grouping and receives grouping from the circuit that is connected to described equipment to the circuit that is connected to described equipment.

20. equipment according to claim 19, wherein, described circuit comprises one at least one attachment circuit that is used for asynchronous transfer mode grouping, frame relay grouping or time division multiplex grouping.

21. an equipment comprises:

Be used for device to network equipment indication Active Performance surveillance coverage and pseudo wire emulation ability;

Be used for monitoring the device of control channel based on the Active Performance of setting up pseudo-line from the response of the described network equipment and being associated with described pseudo-line; And

Be used for monitoring the device of message by described pseudo-line exchange Active Performance.

22. an equipment comprises:

Logic is arranged to:

Receive the announcement label mapping message from the network equipment, the request of described announcement label mapping message is set up Active Performance and is monitored control channel;

Send the answer label mapping message in response to described announcement label mapping message to the described network equipment; And

The Active Performance of setting up pseudo-line and being associated with described pseudo-line monitors control channel.

23. equipment according to claim 22, wherein, described logic further is arranged to:

Use described Active Performance to monitor that control channel monitors described pseudo-line on one's own initiative.

24. equipment according to claim 23, wherein, described logic further is arranged to:

In assessment handling capacity, time delay, packet loss or the shake at least one.

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