CN101611595B

CN101611595B - Multifunctional control channel for pseudowire emulation

Info

Publication number: CN101611595B
Application number: CN2007800513462A
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: 2012-03-21
Anticipated expiration: 2027-12-21
Also published as: CN101611596A; CN101611393B; CN101611393A; CN101611595A; CN101611596B

Abstract

A system advertises a multifunctional control channel (MFCC) in an interface parameter sub-type-length-value (TLV) of an advertisement label mapping message that is dispatched to a network device. The system also processes a reply label mapping message that is transmitted from the network device in response to the advertisement label mapping message and updates a label information base to establish a pseudowire and a MFCC associated with the pseudowire.

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 said 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 through setting up.

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

Description of drawings

Fig. 1 shows the network that on data link layer level, can realize multifunctional control channel 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 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 has explained the example packet that can arrive the pe router of Fig. 1;

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

Fig. 5 C has explained 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 explained 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 explained the example process that is used to use MFCC exchange MFCC message.

Embodiment

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

Implementation described herein can relate to the foundation and/or the use of the multifunctional control channel that is used for transmitting control message through 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 on data link layer level (that is the layer 2 in the OSI(Open Systems Interconnection) network model), can realize multifunctional control channel 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, the for example equipment and/or the system of the such local network services of Ethernet, ATM, frame relay and/or Time Division Multiplexing.Like what further illustrate 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 to get into to be left over the inlet of

network

102 and 104 and/or withdraws 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 be provided entering and withdraw from the inlet of 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 the grouping that arrives through

attachment circuit

108 and 110, IP/MPLS network 106 can be set up the network path that is called as pseudo-line, and can on this puppet line, route divide into groups.

Through 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 route is divided into groups on pseudo-line, multifunctional control channel is set, and/or controls pseudo-line through multifunctional control channel.

Fig. 2 has explained 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 and divide into groups 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 divides into groups and be used for transmitting to network grouping that gets into.Interconnection 210 can comprise the switch that is used for will getting into based on the routing information of grouping destination and storage the line interface 208 that divides into groups to be delivered to from line interface 206.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 in each among the PE/PS router one 16-122 of Fig. 1.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 gets into packet queue.Arrive simultaneously if divide into groups, 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 hardware and/or the software that is used for being stored in the collection routing iinformation and with routing iinformation with other router communications LIB.

Fig. 4 is the exemplary functional block diagram of the forwarding logic 304 of Fig. 3.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 that the header information that is used for being stored based on LFIB 404 and LIB 406 and path/routing iinformation are checked the header that gets into grouping and this grouping sent to the hardware and/or the software of 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 depends on the entering grouping and network configuration possibly operated as pe router 116 or PS router one 20 in condition of different.If host router is operated as pe router 116, then MPLS logic 402 can be as mentioned below through add the MPLS header to dividing into groups, and becomes MPLS to divide into groups the packet switched that gets into network 106.On the contrary, MPLS logic 402 can be changed 106 the MPLS of exitting network and divides into groups through peeling off MPLS header that MPLS divides into groups.

Fig. 5 A has explained the example packet 500 that can arrive pe router 116.As illustrated, 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).Divide into groups after 500 the next destination that MPLS logic 402 can be classified 500 types of being included into that divide into groups based on this, LFIB 404 and/or LIB406 confirm grouping 500 receiving.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 at output line card 208 (Fig. 2) and divide into groups 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 recovering the grouping 500 shown in Fig. 5 A, and can send to network 104 and divide into groups 500.

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 explained the structure of the MPLS header 506 that can comprise label 508.In PS router one 20, label 508 can be confirmed 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.Owing to dividing into groups therefore to divide into groups to have a more than MPLS header 506 through can on this divides into groups, carrying out many operations (that is) during the network 106 at specific PS router one 20 or 122 places.Yet if grouping deviated from network 106, it can be removed from it and get into the MPLS header that has been inserted into since the network 106.

Fig. 6 shows the exemplary functional block diagram of logical routing 306.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 like the hereinafter hardware and/or the software of pseudo-line 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 the message (for example, LDP message) about label.Through 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 from the grouping of external network can be included into the class.Through grouping being categorized among the FEC and based on sending grouping with charge free with the FEC associated tag, 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 confirm 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 confirm 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, dividing into groups 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, the LDP message of the label of binding about the FEC related with leaving over network packet and/or with FEC can created or exchange to pseudo-line logic 604.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 in the direction opposite with another LSP, move.

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 between pe router 116/118, extending 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 packet arrives pe router 116, then pe router 116 can become pseudo-line to divide into groups packet encapsulation (that is conversion) through add pseudo-report from a liner head to dividing into groups.Pe router 116 can be that MPLS divides into groups with packet encapsulation through adding the MPLS header, and can should divide into groups to carry out route towards its destination through 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) to divide into groups through 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.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 through 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 use hardware and/or the software with pseudo-line associated control channel.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 through

pseudo-line.In pe router

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

Signaling logic 802 can allow the sign of pseudo-line and can signal the attribute of pseudo-line through 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 unknown field 902 can be specified LDP message 900 to have UNKNOWN TYPE then whether returned the 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 the 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 maybe parameter needs and/or optional for the value of certain message types 904.

Fig. 9 B shows and is used to force/example format of optional parameters field 910.As shown, mandatory parameters field 910 can comprise can provide classes of packets (that is FEC) the FEC-TLV field 912 of tabulation.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 can be set to constant (for example, being respectively " 0 " and " 0x0100 ") with FEC field 916.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 to control messages that can be through the pseudo-lines transmission 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.Interface parameters sub-TLV 1016 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 this locality and remote attachment circuits, such as attachment circuit 108 address information relevant with 110.Similar with 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.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 can be set to constant (for example, being respectively " 0x00 " and " 0x096B ") with PW interface parameters TLV 1034.Length 1036 can the sub-TLV 1038 of specified interface parameter length.The sub-TLV1038 of each interface parameters can be used for like preceding text 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 through 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 in the sub-TLV 1038 of interface parameters (Figure 10 C), setting up control channel.

Figure 11 A has explained the example format of VCCV parameter field 1102.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 through 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, being distributed like 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-endpoints.For example; CV Class1 110 can indicate control messages can be LSP Ping (promptly; Echo request through LSP) or two-way forwarding detect (BFD) signal, it can represent to be used in forward direction and inverse direction continuous monitoring route or the data path message with the discovery fault.

Return Fig. 8, if constructed pseudo-line and the control channel that is associated, then VCCV logic 804 can be sent and/or receiving control message through 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-lines is divided into groups to differentiate.

Figure 11 B shows the exemplary arrangement of the control word in the control messages 1112.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.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 can be a constant and can the value of being set to (for example, " 0 ") with reserving 1126.Channel type 1128 can be in three values one (for example, " 0x0021 " be used to indicate internet protocol version four (IPv4), " 0x0056 " be used for IPv 6 (IPv6) perhaps " 0x0006 " be used for carrying the BFD channel of the grouping that does not have Internet Protocol (IP)/UDP (UDP) header).

Return Fig. 8; If signaling logic 802 and its peers include both exchange LDP message, then MFCC logic 806 can be through 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 with the VCCV parameter field of being 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.Can the MFCC sign indicating number be registered to IANA,, perhaps can it be registered to IANA like the bit in the CC Class1 108 " 0-2 ".

If constructed pseudo-line and related MFCC, then MFCC logic 806 can be used MFCC through 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 be passed through acquisition and long-range pe router (for example, pe router 118) and attachment circuit (for example, attachment circuit 108 and 110) relevant parameter and begin (frame 1202).In an implementation, can obtain this parameter from network manager or user.In another implementation, can obtain this parameter through 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 be selected the default control channel as any pseudo-line that is used for being established.

Like what further illustrate 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, can label 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, about FEC and and the information of this FEC associated tag can send out the receiving router of the jumping distance between router and the receiving router and keep by being independent of the source.

Process 1200 can comprise announcement (advertise) PWE and MFCC ability (frame 1208).In an implementation,, can be write and 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.

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 transmitted pe router support MFCC.Bit in the CV Class1 110 can be indicated the type of the control messages that can on pseudo-line, transmit.

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.

Like what further illustrate among Figure 13, general PW ID FEC element 1018 or PW ID FEC element 1002 can be used for accomplishing LDP message (frame 1308).For example, in an implementation, general PW ID FEC 1018 or PW ID FEC 1002 can be used for accomplishing the LDP message that combines Fig. 9 A-9C to describe like preceding text.Process 1300 can comprise sends 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 accomplished 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 explained and has been used to the example process 1400 of using MFCC to exchange MFCC message.As shown, process 1400 can be through 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 through adding PW header (that is the MPLS header of indication PW) and carrying out this encapsulation through 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.

Further illustrate like Figure 14, the MFCC message that MFCC message can be encapsulated as have the MPLS header (frame 1406) and encapsulation 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 through answer message.

Preceding text combine that Figure 12-14 describes is used to set up and uses the example process of MFCC to combine the following example of the implementation that Fig. 1,7,9A-9C, 10A-10C and 11A-11C describe to further specify through combining preceding text.Suppose that leaving over

network

102 and 104 for two is the ethernet networks that can set up communication channel through 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 through 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 form of explaining among Fig. 9 A-9C, 10A-10C and the 11A.PS router one 20 can be forwarded to another PS router with label mapping message 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 appeared 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.Through 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 of sending MFCC message to pe router 118 from the network manager.Pe router 116 can be write its control messages, and can this message be encapsulated as MFCC message.This encapsulation can involve inserts control word (for example, being used to from the selected control messages type of answering among the control messages type in the CV Class1 110 in the label mapping message channel type 1128 is set) 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.

The example description of preceding text can how set up MFCC and use it for and transmit control message through pseudo-line.Be different from the VCCV control channel,, then need do not rebulid pseudo-line if on MFCC, send dissimilar control messages to destination equipment.Eliminated rebuliding the needs of pseudo-line through 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 the instruction of preceding text, it is feasible revising and changing, and perhaps can should instruction obtain to revise and change through practice.

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 the different functions classification.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 frame 1202 and/or frame 1302～1320 can be performed at frame 1206 before.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 by executed in parallel.

Will it is obvious that, in the accompanying drawings in the implementation of explanation, 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 the description here 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.

Only if clearly describe, otherwise 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 like the article " " that uses here and to comprise one or more.In the situation that only means an item, " one " or similar language use a technical term.And, only if clearly narration in addition, otherwise phrase " based on " mean " part based on " at least.

Claims

1. method that is used to set up multifunctional control channel 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 said announcement label mapping message and from the said network equipment; And

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

2. the method for claim 1 further comprises:

Under the situation of not removing said pseudo-line, use said 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 said 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 said network equipment indication multifunctional control channel ability; And

Send said announcement label mapping message with charge free the said 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:

Said 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 said announcement label mapping message connective confirm the connectedness among the parameter field confirm the type field bit with indication can be through said multifunctional control channel transmission the type of control messages; And

6. method as claimed in claim 5 further comprises:

Form control messages; And

On said multifunctional control channel, send said 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 said channel type field comprise one or more bit values that connectedness in the said answer label mapping message is confirmed type field; And

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

8. the method for claim 1 further comprises:

Create control messages; And

On said multifunctional control channel, send said control messages.

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

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

10. the method for claim 1 further comprises:

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

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

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

Receive said answer label mapping message: and

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

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

Receive said answer label mapping message; And

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

13. a method that is used to set up multifunctional control channel 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 said multifunctional control channel; And

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

14. an equipment that is used to set up multifunctional control channel comprises:

Be used to send the device of the announcement of multifunctional control channel ability;

Be used for device based on the multifunctional control channel of the response of said announcement being set up pseudo-line and being associated with said pseudo-line;

Be used for the device that on said multifunctional control channel, transmits control message; And

Be used for switch label distribution protocol message with state of indicating said pseudo-line or the device of removing said 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 said pseudo-line.

18. equipment as claimed in claim 14 further comprises:

Be used for the device that receive to divide into groups and send the ply-yarn drill that divides into groups to said attachment circuit from the attachment circuit that is connected to said equipment.

19. comprising, equipment as claimed in claim 18, wherein said attachment circuit is used at least one attachment circuit of one that asynchronous transfer mode is divided into groups, frame relay divides into groups or time division multiplexing is divided into groups.

20. an equipment that is used to set up multifunctional control channel 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 said indication of the said network equipment and being associated with said pseudo-line; And

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

21. an equipment that is used to set up multifunctional control channel comprises:

Be used for device at the interface parameters subtype length value announcement multifunctional control channel of the announcement label mapping message of sending the network equipment with charge free;

The device that is used for the answer label mapping message that processing response transmits in said announcement label mapping message and from the said network equipment; And

Be used to upgrade tag information base to set up the device of the pseudo-line related with said multifunctional control channel.

22. equipment as claimed in claim 21 further comprises:

Be used for being provided with the virtual circuit of said announcement label mapping message connective confirm the connectedness among the parameter field confirm the type field bit with indication can be through said multifunctional control channel transmission the device of type of control messages; And

Be used for said announcement label mapping message is sent with charge free the device of the said network equipment.

23. equipment as claimed in claim 21 further comprises:

Be used to form the device of control messages; And

Be used on said multifunctional control channel, sending the device of said control messages.

24. equipment as claimed in claim 21 further comprises:

Be used to obtain device about the information of the local attachment circuit that is connected to the said network equipment and remote attachment circuits; And

Be used for to be incorporated into about the information of said local attachment circuit and said remote attachment circuits the device of said announcement label mapping message.