CN101611595A

CN101611595A - The multifunctional control channel that is used for pseudo wire emulation

Info

Publication number: CN101611595A
Application number: CNA2007800513462A
Authority: CN
Inventors: 罗曼·克扎诺夫斯基
Original assignee: Verizon Services Corp
Current assignee: Verizon Services Corp
Priority date: 2006-12-21
Filing date: 2007-12-21
Publication date: 2009-12-23
Anticipated expiration: 2027-12-21
Also published as: CN101611393B; CN101611595B; CN101611596A; CN101611393A; CN101611596B

Abstract

A kind of system announces multifunctional control channel (MFCC) (1208) in the interface parameters subtype length value (TLV) of the announcement label mapping message of sending the network equipment with charge free.This system is the answer label mapping message (1210) that transmits in this announcement label mapping message and from this network equipment of processing response and upgrade tag information base to set up pseudo-line and the MFCC related with this puppet line also.

Description

The multifunctional control channel that is used for pseudo wire emulation

Background technology

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) switching network or multiprotocol label switching (mpls) network with the packet switching network that pseudo wire emulation (PWE) is provided (PSN).Can manage with the control channel that is used for pseudo-line and control PWE and related pseudo-line by setting up.

Yet each control channel can only be supplied with specific function, sets up this control channel at this specific function.In order to use dissimilar controlled function, may need to rebulid pseudo-line, this can cause successively based on the downtime of the service of PWE and the running cost of increase.

Description of drawings

Fig. 1 shows the network that can realize multifunctional control channel on data link layer level therein;

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

Fig. 3 is included and/or by the exemplary functional block diagram of the parts of its realization in the PE of Fig. 1 and the PS router;

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

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

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

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

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

Fig. 7 shows the exemplary expression of some parts 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 the example format of the pressure/optional parameters field that is used for 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 10B 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 has illustrated that the example virtual circuit control of the LDP message that is used for setting up pseudo-line confirms (VCCV) parameter field;

Figure 11 B shows the exemplary arrangement of the 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 the example process that is used for setting up the multifunctional control channel that is used for pseudo-line (PW) 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 multifunctional control channel (MFCC) ability; And

Figure 14 has illustrated the example process that is used to use MFCC exchange MFCC message.

Embodiment

Following detailed with reference to the accompanying drawings.Identical Reference numeral in the different accompanying drawings can be represented same or analogous element.(BFD) can be illustrated in forward direction and inverse direction continuous monitoring route or data path to find fault as the term " two-way forwarding detection " that uses herein.

Implementation described herein can relate to foundation and/or the use that is used for the multifunctional control channel that transmits control message by pseudo-line.Multifunctional control channel can be supplied with many functions need not to rebulid under the situation of pseudo-line.

Fig. 1 shows the network 100 that can realize multifunctional control channel on data link layer level (that is the layer 2 in the OSI(Open Systems Interconnection) network model) therein.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 equipment and/or the system of the such local network services of Ethernet, ATM, frame relay and/or Time Division Multiplexing.As further illustrating among Fig. 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 on the customer rs premise and can provide and enters the inlet of leaving over

network

102 and 104 and/or 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 switching is provided.As shown in Figure 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 it is carried out the router of route towards its destination equipment.

Attachment circuit

108 and 110 can comprise that ATM, frame relay, TDM or other layers 2 transmit.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 depend on the equipment (for example, ce router 112) that IP/MPLS network 106 will divide into groups from leave over network 102 and be sent to another equipment (for example, ce router 114) of leaving in the network 104.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 route grouping on this puppet line.

By being provided with and using multifunctional control channel can manage pseudo-line.Be different from the control channel of only supplying with predetermined function, multifunctional control channel can be supplied with many functions in existing of pseudo-line in the phase.Pe router 116/118 and/or PS router one 20/122 can be set up pseudo-line, and the route grouping is provided with multifunctional control channel, and/or controls pseudo-line by multifunctional control channel on pseudo-line.

Fig. 2 has illustrated the block diagram of pe router 116/118 and the PS router one 20/122 of Fig. 1, and it is called as " PE/PS router one 16-122 " hereinafter.Among the PE/PS router one 16-122 each can comprise processor 202, memory 204, line interface 206 and 208, interconnection 210 and bus 212.

Processor 202 can comprise one or more processors, microprocessor and/or be optimised and be used to network and the processing logic of communicating by letter.Processor 202 can be handled grouping and/or network path-related information.Memory 204 can comprise static memory, such as read-only memory (ROM), dynamic memory, carries buffer memory such as random-access memory (ram) and/or plate, is used to store data and machine readable instructions.Memory 204 also can comprise the memory device such as floppy disk, CD ROM, CD read/write (R/W) dish and/or flash memory, and the memory device of other types.Line interface 206 and 208 can comprise that being used for automatic network receives the equipment that enters grouping and be used for transmitting to network grouping.Interconnection 210 can comprise that the routing information that is used for based on grouping destination and storage will enter grouping is delivered to line interface 208 from line interface 206 switch.The example of interconnection 210 can comprise communication bus and switch architecture.Except line interface 206 and 208, bus 212 can comprise such path: the communication between the parts of each router among this path permission PE/PS router one 16-122.

Fig. 3 is included or by the exemplary functional block diagram of the parts of its realization among the PE/PS router one 16-122 of Fig. 1 each.Go out as shown, 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 buffer that enters packet queue.If grouping arrives simultaneously, then one or more groupings can be waited in buffer until the grouping of handling and/or having transmitted 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 the direct packets line interface 208.Logical routing 306 can comprise be used for other router communications to collect routing iinformation and routing iinformation to be stored in hardware and/or the software of LIB.

Fig. 4 is the exemplary functional block diagram of the forwarding logic 304 of Fig. 3.Go out as shown, forwarding logic 304 can comprise MPLS logic 402, tag forwarding information base (LFIB) 404 and tag information base (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 this grouping is sent to suitable output port.LFIB 404 and LIB 406 can comprise form and/or the database and/or the routing iinformation of the network path that is called as label switched path (LSP).LFIB 404 can comprise LIB 406 the frequent part of using and can be less than LIB 406.

It is to operate as pe router 116, pe router 118, PS router one 20 or as PS router one 22 to carry out different routing programs that MPLS logic 402 can depend on its host router.Host router depend on enter the grouping and network configuration may in different situations, operate as pe router 116 or PS router one 20.If host router is operated as pe router 116, then MPLS logic 402 can be as mentioned below by adding the MPLS header to grouping, and the packet switched that enters network 106 is become the MPLS 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 has illustrated the example packet 500 that can arrive pe router 116.As described, grouping 500 can comprise L2 header 502 (that is osi layer level 2 packet headers) and L3 header 504 (that is osi layer level 3 packet headers).After receiving grouping 500, MPLS logic 402 can 500 be included into class with grouping, can classify based on this, LFIB 404 and/or LIB406 determine to divide into groups 500 next destination.In addition, as illustrated among Fig. 5 B, MPLS logic 402 can be inserted MPLS header 506 between L2 header 502 and L3 header 504, and can locate to transmit grouping 500 at output line card 208 (Fig. 2).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 recovering the grouping 500 shown in Fig. 5 A, and can send grouping 500 to network 104.

If host router is operated as PS router one 20, 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 with another MPLS header, and/or removes MPLS header 506.

Fig. 5 C has illustrated the structure of the MPLS header 506 that can comprise label 508.In PS router one 20, label 508 can be determined operation (that is, create and insertion MPLS header, change the MPLS header with another header, perhaps remove the MPLS header) and next destination as the index among LFIB 404 or the LIB 406 by MPLS logic 402.Because through carrying out many operations (that is, at specific PS router one 20 or 122 places) in this grouping during the network 106, therefore grouping may have a more than MPLS header 506 in grouping.Yet if grouping deviated from network 106, it can be removed from it and enter the MPLS header that has been inserted into since the network 106.

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

LDP logic 602 can comprise hardware and/or the software that is used for sharing with other PE that comprise the LDP logic and PS router label.Pseudo-line logic 604 can comprise and be used to set up as the hereinafter hardware of pseudo-line and/or software in greater detail.Other logics 606 can comprise and are used to realize other abilities related with logical routing 306, send such as quality-of-service packet, hardware and/or software.

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 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.

In brief, LDP message can comprise about the information of forwarding equivalence class (FEC) with the label of related with each FEC (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.Send grouping with charge free by grouping is categorized among the FEC and based on the label related 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 118 to pe router 116 LSP.Each LSP among two LSP between pe router 116 and the pe router 118 can be used as MPLS tunnel (for example, such path: the number of the MPLS header in this path in the grouping can be identical at the inlet point and the exit point place thereof in this path) and operates.

Return 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 create or exchange about the FEC related with leaving over network packet and/or with the LDP message of the label of FEC binding.The result of LDP message in return, pseudo-line logic 604 can be set up two LSP on the above-mentioned MPLS tunnel.These two LSP can form bi-directional pseudo-wire, and wherein each LSP can be unidirectional and can move in the direction opposite with another LSP.

Fig. 7 shows the exemplary expression of some parts of pseudo-line 702 and Fig. 1.As illustrated in fig. 7, pseudo-line 702 can extend to attachment circuit 110 and can depend on the

MPLS tunnel

704 and 706 below the extension between pe router 116/118 from attachment circuit 108.If be established, then pseudo-line 702 can transmit the grouping that flows into 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 add pseudo-report from a liner head to grouping.Pe router 116 can be the MPLS grouping with packet encapsulation by adding the MPLS header, and can should divide into groups to carry out route towards its destination 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 comprised in the pseudo-report from a liner head, this grouping can by or can not be sent to attachment circuit 110.

Fig. 8 shows the exemplary functional block diagram of pseudo-line logic 604.Go out as shown, pseudo-line logic 604 can comprise signaling logic 802, virtual connective confirm (VCCV) logic 804, multifunctional control channel (MFCC) logic 806 and/or control messages processing logic 808.As mentioned below, signaling logic 802 can comprise and being used for by using LDP logic 602 and control messages to exchange LDP message to set up and to keep the hardware and/or the software of pseudo-line.VCCV logic 804 can comprise and be used to create and the hardware and/or the software that use the control channel related with pseudo-line.MFCC logic 806 can comprise and be used to create and the hardware and/or the software that use the multifunctional control channel related 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

pe router

116 and 118, control messages processing logic 808 can prevent that control messages is routed to IP/MPLS network 106 equipment in addition.

Signaling logic 802 can allow the sign of pseudo-line and can signal the attribute of pseudo-line by carrying out many functions of being carried out by pseudo-line logic 604.This function can comprise, for example, exchanges LDP message with PS and pe router 116-122, FEC that this LDP message semantic definition is related with leaving over network packet and the label of binding with FEC.

Fig. 9 A shows the example format of the LDP message 900 that can be generated by signaling logic 802.Usually, LDP header (not shown) can be before one or more LDP message 900, and each LDP message 900 can adopt the type lengths values (tlv) form.Shown in Fig. 9 A, LDP message 900 can comprise multiple field, such as unknown field 902, message type field 904, message length field 906, message id field 908 and pressure/optional parameters field 910.If can specifying LDP message 900 to have UNKNOWN TYPE, unknown field 902 whether returns answer to LDP message 900.For example, if unknown field 902 is " 1 ",, then can ignore LDP message 900 if then do not pick out value in the message type field 904 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 908 fields and pressure/optional parameters 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 parameters 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 parameters field 910.Go out as shown, mandatory parameters field 910 can comprise can provide classes of packets (that is FEC-TLV field 912 of tabulation FEC).Fig. 9 C shows the example format that is used for FEC-TLV field 912.FEC-TLV field 912 can comprise multiple 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.

For 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 10B show the exemplary configurations of PW ID FEC element 1002 and general PW ID FEC element 1018 respectively.

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 set to constant value (for example, " 0x80 ").C element 1006 can be specified the control word that whether exists at the control messages that can transmit by the pseudo-line related with PW ID FEC element 1002.For the pseudo-line with multifunctional control channel (MFCC), C element 1006 can be set to be used in reference to and be shown in the value (for example, " 1 ") that has control word in the MFCC control messages.

PW Class1 008 can be represented the type of pseudo-line.The example of PW Class1 008 can comprise that " 0x0001 " is used for frame relay, " 0x0003 " and is used for that the transparent cell of ATM transmits, " 0x0005 " is used for Ethernet, or the like.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 any 32 bit values of one group of pseudo-line of expression.PW ID 1014 can identify specific pseudo-line.The sub-TLV 1016 of interface parameters can be used for providing the information specific to interface, such as attachment circuit (for example, attachment circuit 108 and 110) characteristic.

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 set to constant value (for example, " 0x81 ").As indicated 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.Similar to the sub-TLV of interface parameters 1016, interface parameters TLV 1030 can be used for providing the parameter specific to interface.

Figure 10 C shows the exemplary configurations of interface parameters TLV 1030.Go out as shown, 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 TLV 1034 can be set to constant (for example, being respectively " 0x00 " and " 0x096B ").Length 1036 can the sub-TLV 1038 of specified interface parameter length.The sub-TLV1038 of each interface parameters can be used for as mentioned about the sub-TLV 1016 described similar purposes of interface parameters.

Return 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 control channel in the sub-TLV 1038 of interface parameters (Figure 10 C).

Figure 11 A has illustrated the example format of VCCV parameter field 1102.Go out as shown, 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, four bytes) of VCCV parameter field 1102 and can be set to constant value (for example, " 0x04 ").

CC Class1 108 can carry eight bit fields of the type that is used to indicate control channel (a plurality of), and it is professional that router can receive control by this control channel.Each of bit " 0-2 " in the 8 bits in CC Class1 108 fields can be used for specifying one (for example, distributing as internet assigned number authority (IANA)) in three control channel types.CV Class1 110 can comprise the bit field of the type that is used to indicate the control messages that is used to verify the connectedness between the pseudo-line endpoints.For example, CV Class1 110 can indicate control messages can be LSP Ping (promptly, echo request by LSP) or two-way forwarding detect (BFD) signal, it can represent to be used at forward direction and inverse direction continuous monitoring route or data path to find the message of fault.

Return Fig. 8, if the control channel of having constructed pseudo-line and being associated, then VCCV logic 804 can send and/or receiving control message by control channel.This control channel can carry in the type of message indicated in the CV Class1 110 of VCCV parameter field 1102 in the whole duration of existence of this control channel.If the transmission control messages, then VCCV logic 804 can generate the mark that is called as control word, during setting up at control channel, if CC Class1 108 fields have been specified band inner control channel this control messages and other pseudo-line groupings is differentiated.

Figure 11 B shows the exemplary arrangement of the control word in the control messages 1112.Go out as shown, 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.Go out as shown, 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 related 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).

Return Fig. 8, if signaling logic 802 and its peers include both exchange LDP message, then MFCC logic 806 can be by being written as VCCV parameter field 1102 (Figure 11 A) the sub-TLV 1016 of interface parameters (Figure 10 A) in the PW ID FEC element 1002 (Figure 10 A) and/or in the sub-TLV 1038 of interface parameters (Figure 10 C) multifunctional control channel being set.The VCCV parameter field of being write by MFCC logic 806 1102 can have the form similar to the VCCV parameter field write by VCCV logic 804 1102, difference is that CC Class1 108 can carry the sign indicating number (for example, the bit " 3 " in the bit " 3-7 ") that is used to signal MFCC.The MFCC sign indicating number can be registered to IANA,, perhaps can it be registered to IANA as the bit in the CC Class1 108 " 0-2 ".

If constructed pseudo-line and related MFCC, then MFCC logic 806 can be used MFCC by transmission and/or receiving control message on MFCC.The MFCC control channel can carry indicated one or more type of messages in the CV Class1 110 of VCCV parameter field 1102 in the whole duration of existence of this MFCC control channel.

The MFCC control messages can be carried the PW associated channel header as its control word.Opposite with the channel type 1128 of the PW associated channel header 1116 of VCCV control messages, the channel type 1128 of the PW associated channel header 1116 of MFCC control messages can comprise such value: this value is reflected in MFCC one of appointed function by 110 expressions of CV Class1 during setting up.

Above-mentioned implementation provides the exemplary multifunctional control channel that is used for pseudo-line system, comprise 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 MFCC logic 806, and related message structure and form.Figure 12-14 shows can be by the example process of one or more these system elements execution.

Figure 12 shows the example process 1200 that is used to set up the MFCC that is used for pseudo-line.Process 1200 can begin (frame 1202) by obtaining 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 MFCC and select (frame 1204).In one embodiment, the selection that is obtained can be carried out by user, keeper and/or another equipment.In other implementations, MFCC can selected conduct be used for the default control channel of any pseudo-line that can be established.

As further illustrating among Figure 12, can initiate label distribution (frame 1206).In an implementation, for example, initiate label distribution and can comprise opening and closing LDP session, send and greet (Hello) message, carry out other LDP initialize routines etc.Label distribution can comprise downstream autonomous mode and free label retention mode.In the autonomous mode of downstream, label can be sent to downstream router with the FEC related with this label from router under the situation 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 related with this FEC.

Process 1200 can comprise announcement (advertise) PWE and MFCC ability (frame 1208).In an implementation,, can be write and be sent from the pe router of initiating PWE such as the LDP message of label mapping message in order to announce PWE and MFCC.Figure 13 shows the example process 1300 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 MFCC ability.

As shown in Figure 13, process 1300 can comprise MFCC sign indicating number and the bit value of being set in the CV Class1 110 (for example, " 1 ") (frame 1302) in the CC Class1 108 among VCCV parameter 1102 fields.In an implementation, for example, the MFCC sign indicating number in the CC Class1 108 can be indicated and be transmitted pe router support MFCC.Bit in the CV Class1 110 can be indicated the type of the control messages that can transmit on pseudo-line.

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

As further illustrating among Figure 13, general PW ID FEC element 1018 or PW ID FEC element 1002 can be used for finishing LDP message (frame 1308).For example, in an implementation, general PW ID FEC 1018 or PW ID FEC 1002 can be used for finishing the LDP message of describing in conjunction with Fig. 9 A-9C as mentioned.Process 1300 can 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 the original tag mapping message is sent to.If the information that the pe router at pseudo-line other end place can not be verified in the label mapping message to be comprised, then this answer LDP message can be label release message.Otherwise this answer LDP message can be another label mapping message, and this message can notify pe router to initiate PWE.If this LDP message is label mapping message, then CV Class1 110 fields can comprise the bit of the subclass of the selected function of reflection, and this selected function is announced in the CV of original tag mapping message Class1 110 fields.

Process 1200 can comprise end-tag distribution (frame 1212).In an implementation, according to LDP, this end can involve opening and closing LDP session, sends extra LDP message etc.If pe router is finished the switch label mapping message and upgraded its LIB, then in the opposite direction middle two unidirectional LSP that transmit message can be used as bi-directional pseudo-wire.Pe router can exchange the MFCC control messages on this puppet line.

Figure 14 has illustrated and has been used to the example process 1400 of using MFCC to exchange MFCC message.Go out as shown, process 1400 can be by obtaining that the request of MFCC message 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, perhaps is derived from and leaves over the network equipment.

Control messages can be encapsulated as MFCC message (frame 1404).For example, in an implementation, can be by adding PW header (that is the MPLS header of indication PW) and carrying out this encapsulation by inserting control word (that is, the PW associated channel header 1116).Control word can comprise channel type 1128, and the selected function among the represented function of CV Class1 108 in the label mapping message is answered in its reflection during MFCC sets up.

As further illustrated in Figure 14, MFCC message can be encapsulated as have the MPLS header (frame 1406) and the encapsulation MFCC message can be sent out (frame 1408).In an implementation, the MFCC message of encapsulation can arrive the destination pe router, and if essential, then this destination pe router can respond by answer message.

Above set up and use the example process of MFCC to further specify by following example in conjunction with the implementation of above describing in conjunction with Fig. 1,7,9A-9C, 10A-10C and 11A-11C in conjunction with Figure 12-14 being used to of describing.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 pseudo-line as its communication media.

At pe router 116 places, can obtain the parameter relevant with long-range pe router 118 and attachment circuit thereof 110 by automatic discovery procedure.In addition, pe router 116 can obtain the type of MFCC as the control channel that is used to manage and test pseudo-line.

If pe router 116 has obtained parameter, then pe router 116 can be initiated label distribution, can begin the LDP session with adjacent PS router one 20, and can send label mapping message.This label mapping message can comprise the information with the form that illustrates 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 this 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 this label mapping message.After good authentication, the label mapping message that pe router 118 can upgrade its LIB and can send himself is as answer.This answer can comprise from CC Class1 108 values in the label mapping message of pe router 116.CV Class1 110 values can reflect the control messages type of being supported in the type that is presented from CV Class1 110 fields in the label mapping message of pe router 116.If checking is unsuccessful, then pe router 118 can send label release message.After the answer that receives from pe router 118, 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 the request that sends MFCC message to pe router 118 from the network manager.Pe router 116 can be write its control messages, and this message can be encapsulated as MFCC message.This encapsulation can involve 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 encapsulation can be encapsulated as has the MPLS header.Pe router 116 can send resulting MPLS message to pe router 118.

Example has above illustrated how to set up MFCC and to use it for by pseudo-line and has transmitted control message.Be different from the VCCV control channel,, then do not need to rebulid pseudo-line if on MFCC, send dissimilar control messages to destination equipment.Eliminated rebuliding the needs of pseudo-line by the LDP message, MFCC can increase available service time, flexibility and the reliability of IP/MPLS network.

Aforementioned implementation provides explanation, but should not be detailed or make implementation be limited to disclosed precise forms.Consider instruction above, modifications and variations are feasible, perhaps can obtain modifications and variations by putting into practice this instruction.

For example, although Fig. 8 shows signaling logic 802, VCCV logic 804 and MFCC logic 806 in the pseudo-line logic 604, in other implementations, signaling logic 802, VCCV logic 804 and MFCC logic 806 can have different functional classifications.For example, signaling logic 802 can comprise that VCCV logic 804 and VCCV logic 804 can comprise MFCC logic 806 successively.

In another example, although passed through with reference to process prescription illustrated in Figure 12～14 a series of actions, in other implementations, can revise the order of this action.For example, frame 1204 can be performed before the frame 1202 and/or frame 1302～1320 can be performed before frame 1206.And non-dependent acts can be represented the action that can walk abreast and be performed.For example,

frame

1202,1204 and 1206 can be executed in parallel.

It is evident that, in the accompanying drawings in Shuo Ming the implementation, can in many multi-form softwares, firmware and hardware, realize described herein aspect.The software code or the special-purpose control hardware that are used to realize the reality of these aspects do not limit the present invention.Therefore, under situation about need not, described operation and behavior aspect these, be appreciated that software and control hardware can be designed to realize these aspects based on herein description with reference to specific software code.

And the specific part of implementation can be described to carry out " logic " of one or more functions.This logic can comprise the combination such as the hardware of processor, application-specific integrated circuit (ASIC) or field programmable gate array, software or hardware and software.

Unless clearly describe, the element that uses among the application, action or instruction should not to be interpreted as for implementation described herein be crucial or basic.And, mean as the article " " that uses herein and to comprise one or more.In the situation that only means an item, use term " " or similar language.And, unless in addition clearly the narration, otherwise phrase " based on " mean " to small part based on ".

Claims

1. a method comprises:

In the interface parameters subtype length value of the announcement label mapping message of sending the network equipment with charge free, announce multifunctional control channel;

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

Upgrade tag information base to set up the pseudo-line that is associated with described multifunctional control channel.

2. the method for claim 1 further comprises:

Under the situation of not removing described pseudo-line, use described multifunctional control channel to send dissimilar control messages.

3. the method for claim 1, wherein the announcement multifunctional control channel comprises in interface parameters subtype length value:

Be provided with that virtual circuit in the described announcement label mapping message is connective confirms that multifunctional control channel sign indicating number in the control channel type field among the parameter field is with to described network equipment indication multifunctional control channel ability; And

Send described announcement label mapping message with charge free the described network equipment.

4. method as claimed in claim 3, the multifunctional control channel sign indicating number that wherein is provided with in the control channel type field comprises:

Described control channel type field is set to predetermined value.

5. the method for claim 1, wherein the announcement multifunctional control channel comprises in interface parameters subtype length value:

Be provided with virtual circuit in the described announcement label mapping message connective confirm the connectedness among the parameter field confirm the type field bit with indication can be by described multifunctional control channel transmission the type of control messages; And

6. method as claimed in claim 5 further comprises:

Form control messages; And

On described multifunctional control channel, send described control messages.

7. method as claimed in claim 6 wherein forms control messages and comprises:

Channel type field in the control word is set, makes bit in the described channel type field comprise one or more bit values that connectedness in the described answer label mapping message is confirmed type field; And

Described control word is inserted in multi-protocol label switching (T-MPLS) label bottom of stack in the described control messages.

8. the method for claim 1 further comprises:

Create control messages; And

On described multifunctional control channel, send described control messages.

9. the method for claim 1, wherein the announcement multifunctional control channel comprises in interface:

Notify the described network equipment can select the multifunctional control channel function of supporting to the described network equipment.

10. the method for claim 1 further comprises:

Acquisition is about the local attachment circuit that is connected to the described network equipment and the information of remote attachment circuits; And

To be incorporated into about the information of described local attachment circuit and described remote attachment circuits in the described announcement label mapping message.

11. the method for claim 1 is wherein handled the answer label mapping message and is comprised:

Receive described answer label mapping message: and

Verify that by the interface parameters subtype length value of checking described answer label mapping message the described network equipment supports the ability of described multifunctional control channel.

12. the method for claim 1 is wherein handled the answer label mapping message and is comprised:

Receive described answer label mapping message; And

Based on the value of the affirmation of the connectedness in the interface parameters subtype degree value of described answer label mapping message type field, register the dissimilar control messages that the described network equipment is supported.

13. a method comprises:

Generation is used to set up the request of the multifunctional control channel that is used for pseudo-line;

If described request is accepted, then define a plurality of functions of supporting by described multifunctional control channel; And

If described a plurality of function is accepted, then set up the described multifunctional control channel that is used for described pseudo-line.

14. an equipment comprises:

Processor is used for:

Send the announcement of multifunctional control channel ability;

Based on the multifunctional control channel that the response of described announcement is set up pseudo-line and is associated with described pseudo-line;

On described multifunctional control channel, transmit control message; And

Switch label distribution protocol message is with the state of indicating described pseudo-line or remove described pseudo-line.

15. equipment as claimed in claim 14, one in the wherein said label distribution protocol 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.

16. equipment as claimed in claim 15, wherein said announcement comprises:

The forwarding equivalence class type lengths values.

17. equipment as claimed in claim 14 further comprises:

The tag information base that comprises the network route information relevant with described pseudo-line.

18. equipment as claimed in claim 14 further comprises:

Receive the ply-yarn drill that divides into groups and send grouping to described attachment circuit from the attachment circuit that is connected to described equipment.

19. equipment as claimed in claim 18, wherein said attachment circuit comprise one at least one attachment circuit that is used for asynchronous transfer mode grouping, frame relay grouping or time division multiplexing grouping.

20. an equipment comprises:

Be used for sending the device of the indication of multifunctional control channel ability and pseudo wire emulation ability to the network equipment;

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

Be used for the device that on described multifunctional control channel, transmits control message.

21. an equipment comprises:

Logic is arranged to:

Upgrade tag information base to set up the pseudo-line related with described multifunctional control channel.

22. equipment as claimed in claim 21, wherein said logic is further configured to:

23. equipment as claimed in claim 21, wherein said logic is further configured to:

Form control messages; And

On described multifunctional control channel, send described control messages.

24. equipment as claimed in claim 21, wherein said logic is further configured to: