CN101611596B

CN101611596B - Dynamic configuration of pseudowire emulation control channel types

Info

Publication number: CN101611596B
Application number: CN200780051366XA
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: 2012-06-20
Anticipated expiration: 2027-12-21
Also published as: CN101611595B; CN101611596A; CN101611393A; CN101611393B; CN101611595A

Abstract

A system sends an advertisement of a dynamic control channel (DCC) capability to a remote device, establishes a pseudowire and a DCC associated with the pseudowire based on a response from the remote device to the advertisement, and sends a channel function type (CFT) message that includes information about a control channel function (CCFN) over the DCC to the remote device.

Description

The dynamic-configuration of pseudowire emulation control channel types

Technical field

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 in data link layer level, wherein can realize the network of dynamic control channel;

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

Fig. 3 is included in by in the PE of Fig. 1 and the PS router and/or the exemplary functions structure chart of the PE through Fig. 1 and the assembly of PS realization;

Fig. 4 is the exemplary functions structure chart of the forwarding logic of Fig. 3;

Fig. 5 A shows the example packet at the pe router place that possibly arrive Fig. 1;

Fig. 5 B shows in the example packet with the MPLS header that inserts between two headers of Fig. 5 A;

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

Fig. 6 shows the exemplary functions structure chart of the logical routing of Fig. 3;

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

Fig. 8 shows the exemplary functions structure chart 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 mandatory/selectivity parameter 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 ID FEC element respectively;

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

Figure 11 A shows example virtual circuit control checking (VCCV) parameter field in the LDP message that is used for setting up pseudo-line;

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

Figure 11 C shows the exemplary configurations of the PW correlated channels header of Figure 11 B;

Figure 12 A and 12B show the exemplary configurations of the PW correlated channels header that is used for channel function type (CFT) message and the exemplary configurations of CFT word respectively;

Figure 13 shows the example process of setting up the dynamic control channel that is used for pseudo-line (PW) emulation;

Figure 14 shows the example process that is used to write LDP message, and wherein LDP message can be passed to another pe router with dynamic control channel (DCC) performance from a pe router with PWE;

Figure 15 shows for specific control channel function (CCFN), through the example process of DCC exchange DCC message; And

Figure 16 shows through DCC exchange CFT message to select the example process of CCFN.

Embodiment

Following detailed description is with reference to the accompanying drawing of following.In different drawings, identical Reference numeral can be represented identical or like.As as used herein, term " two-way forwarding detection " (BFD) can refer to lasting monitoring to route or data path, with find forward direction with reverse in mistake.

Realization described herein can relate to the foundation and/or the use of the dynamic control channel that is used for transmitting control message through pseudo-line.

Fig. 1 shows at data link layer level (i.e. layer 2 in the open system interconnection (osi) network model), wherein can realize the network 100 of dynamic control channel.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 and can comprise equipment and/or the system that is used to provide local network services, such as, Ethernet, ATM, frame relay and/or Time Division Multiplexing.As among Fig. 1 shown in further, leave over

network

102 and 104 and can comprise client edge (CE) router one 12 and 114.

Ce router

112 and 114 can comprise the router that is positioned at customer rs premise, and can provide the entering of leaving over

network

102 and 104 and/or withdraw from.

IP/MPLS network 106 can comprise equipment and/or the system that fast packet switching is provided.As seen in fig. 1, IP/MPLS network 106 can comprise provider edge (PE) router one 16 and 118 and provider's exchange (PS) router one 20 and 122.Pe

router

116 and 118 can comprise can be provided the entering of IP/MPLS network 106 and/or the router that withdraws from.PS router one 20 and 122 can comprise accepts that IP/MPLS divides into groups and with they routers to its destination equipment route.

Attachment circuit

108 and 110 can comprise the combination of hardware, software and/or hardware and software, is used for being connected to IP/MPLS network 106 with leaving over

network

102 and 104 through interface.Can move into and shift out IP/MPLS network 106 through

attachment circuit

108 and 110 from and to reaching the grouping of leaving over

network

102 and 104.

Grouping can depend on IP/MPLS network 106 its equipment (for example ce router 112) from leave over network 102 is transferred to another equipment (for example ce router 114) in leaving over network 104.In order to transmit the grouping that arrives through

attachment circuit

108 and 110, IP/MPLS network 106 can be set up network path, is known as pseudo-line, and can be through these pseudo-circuits by grouping.

Through being provided with and using dynamic control channel, can manage pseudo-line.Dynamically control channel can provide (serve) many functions in the whole life of pseudo-line, and is different with the control channel that predetermined function is provided.In addition, dynamically control channel can provide flexibility in its configuration, because when generating dynamic control channel, the controlled function that is used for dynamic control channel can not need designated.Pe router 116/118 and/or PS router one 20/122 can be set up pseudo-line,, dynamic control channel is set and/or controls pseudo-line through these dynamic control channels by grouping through these pseudo-circuits.

Fig. 2 shows the pe router 116/118 of Fig. 1 and the exemplary composition of PS router one 20/122, and these routers are called " PE/PS router one 16-122 " hereinafter.Each of PE/PS router one 16-122 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 optimized to be used to and networks 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, such as random-access memory (ram) and/or COB, is used to store data and machine readable instructions.Memory 204 also can comprise memory device, such as the memory device of floppy disk, CD ROM, CD read/write (R/W) dish and/or flash memory and other types.Line interface 206 and 208 can comprise and be used for receiving grouping that gets into and the equipment that divides into groups to the network transmission from network.Interconnection 210 can comprise interchanger, is used for according to grouping destination and the routing information of being stored, and will get into and divide into groups to be sent to line interface 208 from interface 206.The example of interconnection 210 can comprise communication bus and switching fabric.Except line interface 206 and 208, bus 212 can comprise the path, and this path allows the communication between components in each of PE/PS router one 16-122.

Fig. 3 is included in each of PE/PS router one 16-122 or by the exemplary block diagram of the assembly of each realization of PE/PS router one 16-122.As directed, PE/PS router one 16-122 can comprise buffer-manager 302, forwarding logic 304 and logical routing 306.Buffer-manager 302 can provide buffer for the grouping that queuing gets into.If a plurality of groupings arrive simultaneously, then one or more groupings can wait in buffer, are processed and/or are sent out up to the grouping of higher priority.Forwarding logic 304 can comprise hardware and/or software, is used for according to routing iinformation, with dividing into groups to be directed to the suitable output port on the line interface 208.Logical routing 306 can comprise hardware and/or software, is used for storing routing iinformation with other router communications with collection and at LIB.

Fig. 4 is the exemplary functions structure chart of forwarding logic 304.As directed, 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 hardware and/or software, is used to check get into the header that divides into groups, and is used for according to the header information that is stored in LFIB 404 and LIB 406 and path/routing iinformation grouping being sent to suitable output port.LFIB 404 and LIB 406 can comprise the network path that is called as label switched path (LSP) and/or the table or the database of routing iinformation.LIFB 404 can comprise the more frequent part of using of LIB 406, and can be less than LIB406.

Whether MPLS logic 402 can be carried out different route flow processs, operate as pe router 116, pe router 118, PS router one 20 or PS router one 22 according to its host router.In different instances, host router can be used as pe router 116 or PS router one 20 is operated, and this depends on the grouping and its network configuration of entering.If host router adds the MPLS header to grouping as pe router 116 operations through what be described below, MPLS logic 402 can become 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 through removing MPLS header that MPLS divides into groups.

Fig. 5 A shows the example packet 500 that possibly arrive pe router 116.As shown in the figure, grouping 500 can comprise L2 header 502 (that is osi layer 2 packet headers) and L3 header 504 (that is osi layer 3 packet headers).Divided into groups 500 o'clock receiving, MPLS logic 402 can 500 be categorized into one type with dividing into groups, based on this classification, LFIB404 and/or LIB406, and 500 next destination of can confirming to divide into groups.In addition, MPLS can insert MPLS header 506 between L2 header 502 and L3 header 504, as shown in Fig. 5 B, and can locate to send 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, MPLS logic 402 can be removed MPLS header 506, recovering dividing into groups 500, as shown in Fig. 5 A, and can 500 be sent to network 104 with dividing into groups.

If host router is as PS router one 20 operation, MPLS logic 402 can be to MPLS statistical tables and reports head 506 executable operations of the grouping that receives, and can send (that is route) this grouping based on MPLS header 506.This operation can comprise and generate another MPLS header, and is close to MPLS header 506 and is inserted into, and changes MPLS header 506 into another MPLS header, and/or removes MPLS header 506.

Fig. 5 C shows the structure of the MPLS header 506 that possibly comprise label 508.In PS router one 20, label 508 can be by MPLS logic 402 as the index that gets into LFIB404 or LIB406, to confirm this operation (promptly generate and insert the MPLS header, change the MPLS header into another, or remove the MPLS header) and next destination.Dividing into groups through (for example, at specific PS router one 20 or 122 places) during the network 106, possibly carry out many operations to dividing into groups, grouping possibly have more than a MPLS header 506.Yet if grouping deviated from network 106, it possibly remove the MPLS header that begins to be inserted into from its entering network 106.

Fig. 6 shows the exemplary functions structure chart of the logical routing 306 of Fig. 3.As directed, 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 hardware and/or the software that is used to set up pseudo-line, like hereinafter institute in greater detail.Other logics 606 can comprise hardware and/or the software that is used to realize other performances of being associated with logical routing 306, transmit such as quality-of-service packet.

LDP logic 602 can be implemented the specific flow process (that is, the LDP agreement) of a cover, is used to exchange the message (for example, LDP message) about label.Through the exchange of LDP message, the LIB of each router in network 106 possibly be loaded route and the label information that PE and PS router possibly observed.

Briefly, LDP message can comprise about forwarding equivalence class (FEC) information with each FEC the information of the label of be associated (promptly binding).At pe router 116, for example, each FEC can represent one type, can be put under such from the grouping of external network.Through with being categorized into FEC and these divide into groups based on the label distribution that is associated with FEC, IP/MPLS network 106 can utilize the packet traffic of increase that gradable route service is provided.

If the LDP logic 602 in pe router 116 will be loaded into its LIB406 from FEC and the label information that pe router 118 is propagated (propagate), can be determined the grouping that is used for from attachment circuit 108 arrival pe routers 116 from the label switched path (LSP) of pe router 116 to pe router 118.Similarly; If the LDP logic 602 in pe router 118 is used to load among its LIB406 from the FEC of pe router 116 and label information, then will confirm as the grouping that is used for arriving pe router 118 from the LSP of pe router 118 to pe router 116 from attachment circuit 110.Each of two LSP between pe router 116 and pe router 118 can be used as MPLS tunnel (for example, wherein the inlet point of a plurality of MPLS headers in grouping in this path is identical path with its exit point) operation.

Return Fig. 6, relate to FEC and/or the label information that is used to leave over network packet if logical routing 306 receives or sends, then pseudo-line logic 604 can be called LDP logic 602.Or rather, pseudo-line logic 604 can generate or exchange about with the LDP message of the label of leaving over FEC that network packet is associated and/or binding with this FEC.The result of LDP message in return, pseudo-line logic 604 can be set up two LSP on above-mentioned MPLS tunnel.This two LSP can form bi-directional pseudo-wire, and wherein, each LSP can be unidirectional, and maybe with another LSP at opposite direction operation (run).

Fig. 7 has described the exemplary expression of some assembly of pseudo-line 702 and Fig. 1.As shown in Figure 7, pseudo-line 702 can extend to attachment circuit 110 from attachment circuit 108, and can depend on the lower

floor MPLS tunnel

704 and 706 that between pe router 116/118, extends.If be established, then pseudo-line 702 can transmit grouping, and this divides into groups to flow into pe router 116 from attachment circuit 108.

If packet arrives pe router 116, through pseudo-report from a liner head is added into this grouping, pe router 116 can become pseudo-line to divide into groups with this packet encapsulation (that is conversion).Through adding the MPLS header, pe router 116 can become MPLS to divide into groups this packet encapsulation, and can be with dividing into groups through MPLS tunnel 704 towards its destination route.Occur from the MPLS tunnel 704 at pe router 118 if divide into groups, then pe router 118 can go this grouping to encapsulation (that is, changing back) through removing MPLS header and pseudo-report from a liner head.Be based on the information that is comprised in the pseudo-report from a liner head, grouping can be sent out or can not be sent to attachment circuit 110.

Fig. 8 has described the exemplary functions structure chart of pseudo-line logic 604.As directed, pseudo-line logic 604 can comprise signaling logic 802, virtual Connectivity Verification (VCCV) logic 804, dynamic control channel (DCC) logic 806 and/or control messages processing logic 808.Signaling logic 802 can comprise hardware and/or software, and this hardware and/or software are used for being described below through using LDP logic 602 message and control messages exchange LDP message to set up and safeguarding pseudo-line.VCCV logic 804 can comprise hardware and/or the software that is used to generate and use the control channel that is associated with pseudo-line.DCC logic 806 can comprise hardware and/or the software that is used to generate and use the dynamic control channel that is associated with pseudo-line.Control messages processing logic 808 can comprise the hardware and 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 control messages is routed to the equipment of IP/MPLS network 106 outsides.

Through carrying out by the performed many functions of pseudo-line logic 604, signaling logic 802 can allow the identification of pseudo-line, and sends pseudo-line attribute through signal.These functions can comprise, for example, with PS and pe router 116-122 exchange LDP message, this LDP message semantic definition with leave over FEC that network packet is associated and the label that is tied to this FEC.

Fig. 9 A shows the example format of the LDP message 900 that can be generated by signaling logic 802.Generally speaking, LDP header (not shown) is before one or more LDP message 900, and each LDP message 900 can be taked the type lengths values (tlv) form.As shown in Fig. 9 A, LDP message 900 can comprise a plurality of fields, such as unknown field 902, message type field 904, message length field 906, message id field 908 and mandatory/selectivity parameter field 910.If it is UNKNOWN TYPEs that unknown field 902 can be specified LDP message 900, whether will be returned the answer of LDP message 900.For example, if unknown field 902 is " 1 ", if then the value in message type field 904 is unrecognized at the receiving router place, LDP message 900 can be left in the basket.Message type field 904 can be indicated LDP type of message (for example, keeping connecting (keepalive) message, address message, label mapping message etc.).Message length field 906 can be indicated message id 908 fields represented with eight bit byte and the cumulative length of mandatory/selectivity parameter field 910.Message id field 908 can comprise the value that is used to discern LDP message 900.Mandatory/selectivity parameter field 910 can comprise parameter, and these parameters can be essential and/or optionally for the value of certain message types 904.

Fig. 9 B shows the example format that is used for mandatory/selectivity parameter field 910.As directed, mandatory parameter field 910 can comprise FEC-TLV field 912, and FEC-TLV field 912 can provide (that is FEC) the tabulation, of branch group categories.Fig. 9 C shows the example format that is used for FEC-TLV field 912.FEC-TLV912 can comprise multiple field (for example, zero standard character learning section 914, FEC field 916, length field 918, FEC element field 920 etc.).Zero standard character learning section 914 can be configured to constant (for example, being respectively " 0 " and " 0x0100 ") with FEC field 916.Length field 918 can comprise the value of the length that is used for 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.

As shown in Fig. 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 interface parameters-TLV 1016.PW id 1004 can discern PW ID FEC element 1002 and can be configured to normal value (for example, " 0x80 ").C element 1006 can be specified for the control messages that pseudo-line transmitted through being associated with PW ID FEC element 1002, whether has control word.For the pseudo-line with dynamic control channel (DCC), C element 1006 can be set to a value (for example, " 1 "), has control word to be illustrated in the DCC control messages.

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

As shown in Fig. 10 B, general PW ID FEC element 1018 can comprise general PWid 1020, 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 discern general PWID FEC element 1018, and can be configured to normal value (for example, " 0x81 ").C element 1022 and PW Class1 024 can be specified the information identical with C element 1006 and PW Class1 008, as stated.PW message length 1026 can be specified the length of attachment circuit (AC) information 1028.Attachment circuit information 1028 can be specified the address information that is associated with this locality and remote attachment circuits such as attachment circuit 108 and 110.Interface parameters TLV 1030 can be used to the special interface parameter is provided, and is similar to interface parameters-TLV1016.

Figure 10 C shows the exemplary configurations of interface parameters TLV 1030.As directed, interface parameters TLV 1030 can comprise nil segment 1032, PW interface parameters TLV 1034, length 1036 and/or interface parameters-TLV 1038.Nil segment 1032 can be configured to constant (for example, being respectively " 0x00 " and " 0x096B ") with PW interface parameters TLV 1034.Length 1036 can specified interface parameter-TLV 1038 length.Each of interface parameters-TLV1038 can be used to and above-mentioned interface parameters-TLV 1016 similar purposes that are used for.

Return Fig. 8; If signaling logic 802 and its peer (Peer) exchange LDP message; Through being arranged in the PWID FEC element 1002 as the VCCV parameter field of interface parameters-TLV 1016 (Figure 10 A0) and/or being arranged among interface parameters-TLV 1038 (Figure 10 C), then VCCV logic 804 can be set up control channel.

Figure 11 A shows the example format of VCCV parameter field 1102.As directed, VCCV parameter field 1102 can comprise Class1 104, length 1106, control channel (CC) Class1 108 and Connectivity Verification (CV) Class1 110.Class1 104 can be discerned VCCV parameter field 1102, and can be configured to octet value (for example, " 0x0c ").Length 1106 can provide the length (for example, four bytes) of VCCV parameter field 1102, and can be configured to normal value (for example " 0x04 ").

CC Class1 108 can carry the type that an eight bit word section is represented control channel, and through this control channel, router can receive the control flow.In eight of in CC Class1 008 field these, each of position " 0-2 " can be used to specify one of three control channel types (for example, being distributed like the Internet numbering distributor gear (IANA)).CV Class1 110 can comprise a bit field, is used to verify the type of the control messages of the connectedness between pseudo-endpoints with expression.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, its continuous monitoring that can refer to be used for route or data path is to find the message of the fault on forward direction and inverse direction.

Refer again to Fig. 8, if make up pseudo-line and associated control channel, VCCV logic 804 can be sent and/or receiving control message through this control channel.In the The whole control channel lifecycle, this control channel can carry one of type of message of indicating in the CV Class1 110 of VCCB parameter field 1102.If transmit control message, then VCCV logic 804 can generate the mark that is known as control word, in order to: if band inner control channel is specified by CC Class1 108 fields setting up in the process of control channel, then the pseudo-line packet zone of control messages and other is separated.

Figure 11 B shows the exemplary setting of the control word in control messages 1112.As directed, this control word can be a PW correlated channels header 1116, and is arranged between the MPLS label stack 1120 and L3 header 1114 that comprises MPLS header 1118.Figure 11 C shows the exemplary configurations of PW correlated channels header 1116.As directed, PW correlated channels header 1116 can comprise nibble 1122, version 1124, reservation 1126 and channel type 1128.Nibble 1122 can be indicated the channel that is associated with pseudo-line, and is configured to a value (for example, " 0x01 ").Version 1124 can be a constant with keeping 1126, and is set to a value (for example " 0 ").Channel type 1128 can be one of three values (for example, " 0x0021 " of indication internet protocol version 4 (Ipv4), be used for internet protocol version 6 (Ipv6) " 0x0056 ", or be used to carry do not have Internet protocol (IP)/" 0x0006 " of the BFD channel of UDP (UDP) header).

Refer again to Fig. 8; If signaling logic 802 and its peer exchange LDP message; Then through writing PWID FEC element 1002 (Figure 10 A) as the VCCV parameter field 1102 (Figure 11 A) of interface parameters-TLV1016 and/or writing interface parameters-TLV 1038 (Figure 10 C), DCC logic 806 can be provided with dynamic control channel.

More specifically, DCC logic 806 can write CC Class1 108 with the place value " 1 " that is used for DCC position (for example, the position " 5 " in " 3-7 " on the throne).In CC Class1 108, can in the IANA registration, can not register as the position " 0-2 " in CC Class1 108 as the position of DCC position at IANA yet.

In addition, whether DCC logic 806 type (that is, DCC operating period) after the foundation of DCC that can in CV Class1 10, indicate the control channel function (CCFN) that DCC supports can be consulted by pe router.If the type of CCFN will be consulted before the foundation of DCC, then DCC logic 806 can be in CV Class1 10, the type indication of the CCFN that can support by DCC.In this instance, CV Class1 110 can carry existing code (that is the code of, registering at IANA) or the fresh code that is used for the CV type.

In case made up pseudo-line and associated DC C, DCC logic 806 can be sent through DCC, receives and/or processing DCC control messages, and is as mentioned below.In addition, DCC logic 806 can be set up the specific CCFN that is used for DCC through exchange channel function type (CFT) message, and is as mentioned below.

The DCC control messages can be carried PW correlated channels header, as its control word.With the channel type of the PW correlated channels header 1116 that is used for the VCCV control messages 1128 forms contrast be; The channel type 1128 that is used for the PW correlated channels header 1116 of DCC control messages can comprise a value, and this value reflects by one of function of appointed CV Class1 110 representatives during setting up at DCC.

Channel function type (CFT) message can be carried PW correlated channels header and followed this PW correlated channels header CFT word afterwards closely.Figure 12 A and 12B show the PW correlated channels header 1202 that is used for CFT message and the exemplary configurations of exemplary configurations and CFT word 1212 respectively.

As shown in Figure 12 A, PW correlated channels header 1202 can comprise nibble 1204, version 1206, keep 1208 and PW state of a control 1210.Nibble 1204, version 1206 and keep 1208 can be respectively with nibble 1122, version 1124 with keep 1126 similarly, and can be used for similar purpose.PWE state of a control 1210 can comprise that indication CFT word follows PW correlated channels header 1202 place value afterwards closely.Can discern and handle CFT message through inspection PWE state of a control 1210, DCC logic 806.

As shown in Figure 12 B, CFT word 1212 can comprise CFT 1214, version 1216, keep 1218, CFT type of message 1220, channel type 1222 and keep 1224.CFT 1214 can carry the place value that this CFT message is identified as the CFT type.Version 1216 can be configured to a value (for example, " 0x0000 "), and keeps 1218 and can be left a blank.CFT type of message 1220 can be discerned the type of CFT message, and it is described hereinafter.Channel type 1222 can comprise the value of one of function that reflection CV Class1 110 can be represented.Keeping 1224 can be left a blank.

CFT type of message 1220 can comprise one of following type: set up the request of request, dismounting (tear down) CCFN of CCFN, for the request responding of setting up CCFN, for the request responding of removing CCFN and other.Can send the request of setting up CCFN by pe router, with the setting of initialization control channel function.Can send the request of removing CCFN with reference to existing CCFN.Can comprise affirmation (ACK) message for the request of setting up CCFN or for the request responding of removing CCFN.If do not comprise ACK message for the request responding of setting up CCFN, then this response can comprise refuse information, and this refuse information can comprise the code of the reason of specifying this request of refusal successively.This code can be indicated, and for example, the CCFN that is asked is not supported, and the CCFN that is asked has existed, and perhaps the number of CCFN is not supported (that is the maximum number of the CCFN that, has been able to support).This code can be indicated other conditions, and this depends on the realization details.

Above-mentioned execution mode provides the exemplary dynamic control channel that is used for pseudo-line system; Comprise, such as system element and the related news structure and the form of PE/PS router one 16-122, forwarding logic 304, logical routing 306, pseudo-line logic 604, signaling logic 802, VCCV logic 804 and DCC logic 806.Figure 13-16 has described can be by the performed example process of one or more these system elements.

Figure 13 shows the exemplary process 1300 of setting up the DCC that is used for pseudo-line.Handle 1300 and can begin (piece 1302) through obtaining the parameter that is associated with long-range pe router (for example, pe router 118) and attachment circuit (for example,

attachment circuit

108 and 110).In an enforcement, these parameters can be obtained from network manager or user.In another was implemented, these parameters can obtain through dynamic auto discovery flow process.

Can obtain DCC and select (piece 1304).In an enforcement, the selection that is obtained can be made by user, keeper and/or through another equipment.In other are implemented, can DCC be selected to be used for any pseudo-line that can be established as the acquiescence control channel.

Like what in Figure 13, further illustrated, can initiate label distribution (piece 1306).In an enforcement, for example, initiate label distribution and can comprise opening and closing LDP session, send hello messages, carry out other LDP initialization flow processs etc.Label distribution can comprise downstream autonomous mode and free label retention mode.In the autonomous mode of downstream, label and the FEC that is associated with these labels can be sent to downstream router from a router under the situation from the request of downstream router not.In label retention mode, can keep by the receiving router that is independent of initiating the hop distance between router and the receiving router about the information of FEC and the label that is associated with FEC.

Handle 1300 and also can comprise announcement (advertise) PWE and DCC performance (piece 1308).In an enforcement, in order to announce PWE and DCC, can write from the pe router of initiating this PWE and send such as the LDP message of label mapping message.Figure 14 shows and is used to write the example process that PWE and DCC performance is sent to the LDP message of another pe router from a pe router.

As shown in Figure 14, process 1400 can comprise that DCC position and the position in the CV Class1 110 in the CC Class1 108 in VCCV parameter 1102 fields is set to a value (for example " 1 ") (piece 1402).In one embodiment, for example, DCC position (that is the pre-determined bit in the position " 3-7 " in CC Class1 108) can indicate and send pe router support DCC.Position in CV Class1 110 can indicate the type of control channel function (CCFN) after DCC sets up to be consulted by pe router.If these do not indicate the type of CCFN after DCC sets up to be consulted, these can indicate the type of the CCFN that possibly support so.

VCCV parameter field 1102 can be used to form interface parameters-TLV1038 (piece 1404).Interface parameters-TLV1038 can be used to form general PW ID FEC element 1018 or PW ID FEC element 1002 (piece 1406).In an enforcement, in forming general PW IDFEC element 1018 processes, the information about attachment circuit that obtains in piece 1202 places can be merged into attachment circuit information 1028.

As among Figure 14 shown in further, general PW ID FEC 1018 or PW ID FEC1002 can be used to accomplish LDP message (piece 1408).For example, in an enforcement, general PW ID FEC 1018 or PW ID FEC 1002 can be used to accomplish LDP message, combine Fig. 9 A-9C described like preceding text.Process 1400 also can comprise sends LDP message (piece 1410).The LDP message that can be sent out comprises, for example, and notification message, label request message, label release message, label mapping message etc.

Refer again to Figure 13, process 1300 can comprise receiving answers LDP message (piece 1310).In an enforcement, to answer LDP message and can initiate from pe router, the original tag mapping message is sent to this pe router.If the pe router at the other end of pseudo-line can not be verified the information that is included in the label mapping message, then answering LDP message can be label release message.Otherwise answering LDP message can be another label mapping message.If answering LDP message is label mapping message, then CV Class1 110 fields can indicate that CCFN can be consulted after setting up DDC, or support specific CCFN.

Label distribution can be updated or finish (piece 1312).In an enforcement, end possibly relate to according to LDP, and other LDP message etc. is sent in opening and closing LDP session.If pe router is accomplished the switch label mapping message and upgraded its LIB, then two of message transfer unidirectional LSP can be used as bi-directional pseudo-wire in the opposite direction.

In process 1300, can specify CCFN in announcement (advertisement) label mapping message and the position of answering the CV Class1 110 in the label mapping message.In this instance,, can exchange the DCC control messages that is used to specify CCFN through the DCC that has set up.Figure 15 shows the example process 1500 through the exchange control messages that is used for specific CCFN.

As directed, process 1500 can begin (piece 1502) from obtaining the request that is used for the DCC control messages.In an enforcement, this request can perhaps be initiated from leaving over the network equipment from the user and/or the keeper of pe router or from remote equipment.

Control messages can be encapsulated as DCC control messages (piece 1504).For example, in an enforcement, through adding PW header (that is the MPLS header of indication PW) and, can carrying out this encapsulation through inserting control word (that is, PW correlated channels header 1116).This control word can comprise channel type 1128, and channel type 1128 has reflected one of selected function in can be by those functions of CV Class1 108 representatives in the answer label mapping message during DCC sets up.

As among Figure 15 shown in further, the DCC control messages can utilize MPLS header (piece 1506) to encapsulate, and this DCC control messages can be sent out (piece 1508).In an enforcement, packaged DCC control messages can arrive the destination pe router, and if necessary, the destination pe router can respond with answer message.

In process 1300, carry out CCFN after the position in the CV Class1 110 in announcement label mapping message and answer label mapping message can be indicated and set up DCC and consult.In this instance, the DCC that CFT message can be passed through to be set up exchanges.Figure 16 shows and is used for through DCC exchange CFT message to select the example process 1600 of CCFN.

As directed, process 1600 can begin (piece 1602) from the request of obtaining CFT message.In an enforcement, this request can be initiated from the user and/or the keeper of pe router or from remote equipment or from leaving over the network equipment.

The message that is used to consult CCFN can utilize CFT word and PW correlated channels header to encapsulate (piece 1604).Whether this CFT message can be indicated in this CFT word in CFT type of message 1220 is the request that is used to set up CCFN, the request of removing CCFN, for the answer of request etc.PW correlated channels header 1210 can comprise PWE state of a control 1210, and it can indicate the CFT word to follow closely after PW correlated channels header 1210.

As among Figure 16 shown in further, can utilize the PW header to come encapsulation messages (piece 1606).It is pseudo-line message that the PW header can be indicated this message.

The message of this encapsulation can also adopt the MPLS header to come further encapsulation (piece 1608), to generate CFT message.In an enforcement, packaged CFT message can be sent out (piece 1610), and can arrive the destination pe router; And; If necessary, this destination pe router can respond to answer CFT message, and answering CFT message can generate according to piece 1604-1608.This answer can be received (piece 1612) at the pe router place that sends this original CFT message.

The described example process that is used to set up and use DCC of above-mentioned combination Figure 13-16 can be come further explaination through combining above-mentioned following example with reference to accompanying drawing 1,7,9A-9C, 10A-10C, 11A-11C and the described enforcement of 12A-12B.Suppose that leaving over

network

102 and 104 for two is Ethernets, it can set up communication channel through the pe router in IP/MPLS network 106 116 and 118.In addition, suppose that

pe router

116 and 118 can be with the communication media of pseudo-line as them.

At pe router 116, can obtain through automatic discovery flow process with long-range pe router 118 and the parameter that its attachment circuit 110 is associated.In addition, pe router 116 can obtain the type of DCC as the control channel that will be used to manage and test pseudo-line.

If pe router 116 obtains these parameters, then pe router 116 can be initiated label distribution, and can begin and the LDP session that is close to PS router one 20, and can send label mapping message.This label mapping message can comprise with the information at the form shown in 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 IP/MPLS network 106 can continue to broadcast label mapping message, receives this label mapping message up to router one 18.

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, pe router 118 can upgrade its LIB and can send its oneself label mapping message as answer.This answer can comprise CC Class1 108 values in the label mapping message from pe router 116.CV Class1 110 values can be indicated and after setting up DCC, confirmed CCFN.

If checking is unsuccessful, then pe router 118 can send label release message.Receiving from pe router 118 when answering, pe router 116 can upgrade its oneself LIB.Through the aforesaid exchange of label mapping message, can set up bi-directional pseudo-wire.

Utilize the pseudo-line that is provided with, pe router 116 can receive request from the network manager, CFT message is sent to pe router 118 to select CCFN.Pe router 116 can write it and select the message of CCFN and can this message be encapsulated as CFT message.This encapsulation can relate to inserts control word and CFT word and additional PW header.Can utilize the MPLS header to come the further packaged message of encapsulation.Pe router 116 can be sent to pe router 118 with the MPLS message that generates, and pe router 118 can send answers CFT message, answers its support to selected CCFN of CFT message authentication, or refuses this CCFN.Refuse CCFN if answer CFT message, then answered the code that CFT message can comprise the reason that provides refusal CCFN.If CCFN is accepted, then the pe router 116 DCC control messages that can continue to be used for the CCFN of this selection is sent to pe router 118.

How above-mentioned example sets up DCC and how to use DDC to send CFT message and DCC message through pseudo-line if showing.Different with the VCCV control channel, if dissimilar control messages is sent to destination equipment, then need not rebulid pseudo-line through DCC.In addition, when setting up DCC, need not confirm CCFN.Through eliminate the needs that rebulid the needs of pseudo-line and CCFN is set through the LDP message when DCC sets up, DCC can increase available service time, flexibility and the reliability of IP/MPLS network.

Aforementionedly explanation is provided, but and has been not intended to and exhaustively maybe enforcement is limited to disclosed precise forms the description of implementing.According to above-mentioned instruction, it is possible revising and changing, and perhaps can from the practice of these instructions, obtain.

For example, though Fig. 8 shows signaling logic 802, VCCV logic 804 and DCC logic 806 in pseudo-line logic 604, in other embodiments, signaling logic 802, VCCV logic 804 and DCC logic 806 can have the difference in functionality level.For example, signaling logic 802 can comprise VCC logic 804, and VCCV logic 804 can comprise DCC logic 806 successively.

In another example, though the series of operations that combined the process prescription shown in Figure 13-16, in other were implemented, the order of these operations can be modified.For example, piece 1304 can be carried out before piece 1302.And, dependent/non-dependent operation can represent can by executed in parallel operation.For example,

piece

1302,1304 and 1306 can be by executed in parallel.In another example,

piece

1402,1404 and 1406 can be by executed in parallel.

Obvious many aspects described herein can be with many multi-form realization of the software among the embodiment shown in the figure, firmware and hardware.Be used to realize that the actual software code of these aspects or special-purpose control hardware do not limit the present invention.Therefore, the operation and the behavior of these aspects are not described with reference to specific software code---it should be understood that the description based on here, can design software and control hardware realize these aspects.

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

Employed element, operation or instruction should not be regarded as the crucial or essential content for these embodiment described herein among the present invention, describe only if having in addition clearly.And as as used herein, the item that does not add numeral-classifier compound is intended to comprise one or more.When referring to an item, " one (one) " or similar language throughout use a technical term.And, phrase " based on " mean " at least in part based on ", only if clearly statement is arranged in addition.

Claims

1. one kind is used for transmitting control message to realize the equipment of dynamic control channel through pseudo-line, comprising:

Be used for the announcement of dynamic control channel performance is sent to the device of remote equipment;

Be used for based on from of the response of said remote equipment, set up pseudo-line and the device of the dynamic control channel that is associated with said pseudo-line said announcement; And

Be used for to comprise the device that is sent to said remote equipment about the channel function kind of message of the information of control channel function through said dynamic control channel.

2. according to the said equipment of claim 1, wherein, said channel function kind of message comprises: control word and channel function class type-word.

3. according to the said equipment of claim 2, wherein, said control word comprises:

Pseudo wire emulation state of a control word follows closely after said control word to indicate said channel function class type-word.

4. according to the said equipment of claim 2, wherein, said channel function class type-word comprises:

It is request or affirmation that channel function kind of message type field, said channel function kind of message type field are indicated said channel function kind of message; And

The channel type field, said channel type field is specified said control channel function.

5. according to the said equipment of claim 1, wherein, said channel function kind of message comprises the reason of refusing to set up said control channel function.

6. according to the said equipment of claim 5, wherein, it is one of following that said reason comprises:

Said control channel function is established;

Said control channel function is not supported;

Reached the maximum number of the control channel function that can be supported; Perhaps

Said control channel function has been established and has reached the maximum number of the control channel function that can be supported.

7. according to the said equipment of claim 1, wherein, said announcement comprises:

The forwarding equivalence class type lengths values.

8. one kind is used for transmitting control message to realize the method for dynamic control channel through pseudo-line, comprising:

Request dynamic control channel in the interface parameters subtype length value of the announcement label mapping message that is sent to the network equipment;

The answer label mapping message that processing response is sent in said announcement label mapping message and from the said network equipment; And

Upgrade tag information base, with the dynamic control channel of setting up pseudo-line and being associated with said pseudo-line.

9. according to Claim 8 said method, wherein, the request dynamic control channel comprises:

Connectivity Verification type field in the virtual circuit Connectivity Verification parameter field in the said announcement label mapping message is set, to consult the control channel function type.

10. according to Claim 8 said method, wherein, handle and answer label mapping message and comprise:

Through checking the field value in the Connectivity Verification type field in the virtual circuit Connectivity Verification parameter field in the said answer label mapping message, accept by the selected control channel function of the said network equipment.

11. said method according to Claim 8, wherein, the request dynamic control channel comprises:

Connectivity Verification type field in the virtual circuit Connectivity Verification parameter field in the said announcement label mapping message is set, consults the control channel function with the dynamic control channel that indication will be passed through to be set up.

12. said method according to Claim 8 also comprises:

To ask the controlled function kind of message to be sent to the said network equipment,, perhaps remove the control channel function of having set up to set up the control channel function.

13. the said method according to claim 12 also comprises:

Receive answer channel function kind of message from the said network equipment, said answer channel function kind of message is confirmed described request channel function kind of message.

14. the said method according to claim 12 also comprises:

Receive answer channel function kind of message from the said network equipment, said answer channel function kind of message refusal is set up the control channel function.

15. the said method according to claim 12 also comprises:

Through said dynamic control channel, exchange the control messages that is used for the said control channel function of having set up with the said network equipment.

16. said method according to Claim 8 also comprises:

Equipment place at the said dynamic control channel of request forms control messages; And

Send said control messages to the said network equipment through said dynamic control channel.

17., wherein, form control messages and comprise according to the said method of claim 16:

The channel type field is set, so that said channel type field is included in the value of the Connectivity Verification type field in the said answer label mapping message in control word; And

Said control word is inserted in the said control messages.

18. said method according to Claim 8, wherein, the request dynamic control channel comprises:

Dynamic control channel value in the control channel type field in the virtual circuit Connectivity Verification parameter field in the said announcement label mapping message is set, to indicate dynamic control channel performance to the said network equipment.

19., wherein, dynamic control channel value is set in the control channel type field comprises according to the said method of claim 18:

Said control channel type field is arranged to predetermined code.

20. one kind is used for transmitting control message to realize the equipment of dynamic control channel through pseudo-line, comprises:

Be used for the indication of dynamic control channel performance and pseudo wire emulation performance is sent to the device of the network equipment;

Be used for based on from of the response of the said network equipment, set up pseudo-line and the device of the dynamic control channel that is associated with said pseudo-line said indication; And

Be used for the device that transmits control message through said dynamic control channel.

21. one kind is used for transmitting control message to realize the equipment of dynamic control channel through pseudo-line, comprises:

Be used for receiving the device of the announcement of dynamic control channel performance from remote equipment;

Be used for based on said announcement, set up pseudo-line and the device of the dynamic control channel that is associated with said pseudo-line; And

Be used for to comprise the device that is sent to said remote equipment about the channel function type response of the information of control channel function through said dynamic control channel.

22. according to the said equipment of claim 21, wherein, said channel function type response comprises:

Control word and channel function class type-word.

23. according to the said equipment of claim 21, wherein, said channel function type response comprises the reason of refusing to set up said channel controlled function.

24. according to the said equipment of claim 23, wherein, it is one of following that said reason comprises:

Said control channel function is established;

Said control channel function is not supported;

The maximum number of the control channel function that has been able to be supported; Perhaps

Said control channel function has been established and has been able to the maximum number of the control channel function that is supported.