CN1747445A

CN1747445A - Router for multicast redundant routing and method for multicast redundancy

Info

Publication number: CN1747445A
Application number: CNA2005100835971A
Authority: CN
Inventors: 吉本哲郎; 续木彰人
Original assignee: Hitachi Communication Technologies Ltd
Current assignee: Hitachi Communication Technologies Ltd
Priority date: 2004-09-06
Filing date: 2005-07-11
Publication date: 2006-03-15

Abstract

In the IGMP/MLD Proxy, a link to an upper router must be formed in a tree structure. However, in this case, if a fault is generated in the link to the upper router, multicasts to the lower networks are all disabled. Plural links to the upper router may be set up using a routing protocol such as PIM, but light and easier operations of the IGMP/MLD Proxy are lost. In view of solving this problem, alternative links may be set in addition to the links which are usually used as the links to the upper router. Usually, the IGMP/MLD is exchanged only with the links which are usually used but with the alternative link. If link-off is detected in the link to the upper router used generally, the IGMP Membership Report/MLD Listener Report packet is transmitted to the side of the alternative link and thereafter the upper link is switched through exchanges of the IGMP/MLD only with the side of the alternative link.

Description

Multileaving redundant path router, multileaving redundancyization method

Technical field

The present invention relates to the Route Selection of IP multileaving.

Background technology

It is man-to-man communication basically that common IP message transmits.It is called the IP single-point transmits.Relative therewith, use network to realize the technology of the broadcast service as image transmits as being used to, IP multileaving technology is arranged.It is by by the router branch on the IP network, will be delivered to the structure of a plurality of main frames from the IP message that information sending server is sent.Thus, information sending server does not need to repeat to send a main frame several, has alleviated burden.In addition, because not returning, the message of same content all do not pass through same path several times, so, alleviated burden as network integral body yet.

Agreements such as PIM and DVMRP are arranged in the multileaving Route Selection, and can set and move also light the most easily be the IGMP/MLD agency.Its structure is as follows: putting the agreement that is used for main frame adding multileaving group in order by the gateway of LAN is IGMP (IPv4)/MLD (IPv6), and sends it to the upper strata router.IGMP is the agreement of using in the IPv4 multileaving, and MLD is the agreement of using in the IPv6 multileaving.Gateway is handled adding breakaway message from main frame by each multileaving group, and the total interface that has the participant is sent the multileaving message.In addition, also regularly whether there is participant's affirmation etc. by router.

Owing to is that tree is a prerequisite with network configuration, though can not use in whole network area since action light, set also than being easier to, so widely-used in the terminal of provider network etc.

[non-patent literature 1] draft-ietf-magma-igmp-proxy-04.txt:IGMP/MLD-based Multicast Forwarding (" IGMP/MLD Proxying ")

[non-patent literature 2] RFC3376:Internet Group Management Protocol, Version 3

[non-patent literature 3] RFC2710:Multicast Listener Discovery (MLD) forIPv6

[non-patent literature 4] draft-vida-mld-v2-08.txt:Multicast Listener DiscoveryVersion 2 (MLDv2) for IPv6

[non-patent literature 5] RFC1075:Distance Vector Multicast Routing Protocol

[non-patent literature 6] RFC2362:Protocol Independent Multicast-SparseMode (PIM-SM): Protocol Specification

Below, technical problem to be solved by this invention is described.

Fig. 2 has been to use IGMP/MLD agency's network schemer figure.The 1st, carry out IGMP/MLD agency and carry out the router that multileaving distributes.2, the 7th, in the Internet, use PIM and DVMRP to wait and carry out the router that multileaving distributes.5a, 5b are the terminals that finally receives multileaving.The 6th, use the transmission router of the multileaving that PIM and DVMRP etc. form on the internet.The 8th, carry out the server that the multileaving message sends at first.1 uses link 3 behind router two reception multileaving message, uses

link

4a, 4b to come to send the multileaving message to

terminal

5a, 5b respectively.Network configuration is not a tree in the Internet 9, but in the IP network 10 of particular job person management, and network configuration is for being the tree on summit with the router two.

Fig. 3 is the sequential chart of basic structure of the expression IGMP/MLD agency's that used Fig. 2 multileaving Route Selection.

The link 3 of router two to being set at the interface that holds the multileaving terminal regularly sends the apply for information that IGMP member inquiry/MLD listeners inquire (below be called apply for information).This message arrives router one (S301) through link 3.With respect to this, if having the multileaving terminal under the self-management, then router one returns IGMP member report/MLD listener and reports (below be called report message).But, owing to do not have the multileaving terminal in this stage, so do not respond (S302).

Router one and router two are same, to self being set to link 4a, the 4b of the interface that holds the multileaving terminal, send apply for information termly.This message is through

link

4a, 4b difference incoming

terminal

5a, 5b (S303a, S303b).But, owing to be not in the system that receives the multileaving message in this stage terminal, so do not respond (S304a, S304b).Therefore, the multileaving message that sends through router 7 from server 86 arrives router twos through the multileaving path, but does not send (S305) forward from it.Receive system if terminal 5a is multileaving, then report message is sent to link 4a temporarily.This message arrives router one (S306) through link 4a.The router one that has received report message is set the transmission that link 4a carries out multileaving, simultaneously, makes the information that is received generate report message, and sends to router two temporarily.Report message is after link 3 arrives router two, and router two is set (S307) to the transmission that link 3 carries out multileaving.

Thus, the multileaving message that sends from server 8 is through router two, router one incoming terminal 5a.And do not arrive 5b (S308).Receive system if terminal 5b is multileaving, then report message is sent to link 4b temporarily.This message arrives router one (S309) through link 4b.The router one that has received report message is set the transmission that link 4b carries out multileaving.Owing to router two has been sent report message before, so at this moment do not send interim report message (S310).Thus, the multileaving message that sends from server 8 is sent to

terminal

5a, 5b both (S311) through router two, router one.If there is the apply for information (S312) that arrives under the state of multileaving terminal from router two the subordinate of router one, then router one returns report message to router two, and shows and have terminal (S313) in the multileaving group.In addition, be in terminal 5a, the 5b that multileaving receives system the apply for information (S314a, S314b) from router one is returned report message, and show and have terminal (S315a, S315b) in the multileaving group.

As mentioned above, at present, among the IGMP/MLD agency, be necessary for a tree to the link of upper strata router.But, thus,, then all obstructed to multileaving than the network of its lower floor if produce obstacle to the link of upper strata router.If use routing protocols such as PIM, it is a plurality of may making the link to the upper strata router, but has lost IGMP/MLD agency's brisk and simplicity.

Summary of the invention

As link, except normally used, also can set the replacement link to the upper strata router.Usually only in normally used link, carry out the exchange of IGMP/MLD, in proxy link, do not carry out the exchange of IGMP/MLD.Under the situation that the link that detects to normally used upper strata router opens circuit,, afterwards, switch the upper strata router by the exchange of only carrying out IGMP/MLD with the replacement link side to replacing link side to send IGMP member report/MLD listener report message.The detection that link opens circuit has

1) link of monitoring physical interface blocks

2) shift the information of (stream is used) single-point Route Selection

3) monitor methods such as having or not the IGMP/MLD inquiry.

The invention effect

By the present invention, can under the situation of the brisk and simplicity that keeps the IGMP/MLD agency substantially, make link redundancyization to the upper strata router

Description of drawings

Fig. 1 is a sequential chart of having represented the action of network integral body of the present invention;

Fig. 2 is the network structure of the problem of expression invention;

Fig. 3 shows the sequential chart of action of network integral body of the problem of expression invention;

Fig. 4 is a network structure of the present invention;

Fig. 5 is the internal structure ideograph of IGMP/MLD agent router of the present invention;

Fig. 6 is the functional block diagram of IGMP/MLD Agent of the present invention;

Fig. 7 is the functional block diagram of IGMP/MLD Agent of the present invention;

Fig. 8 is the functional block diagram of IGMP/MLD Agent of the present invention;

Fig. 9 is of the present invention group of database diagram of expression.

Embodiment

Fig. 4 has been to use the ideograph of the network configuration under the situation of the present invention.Compare with Fig. 2, the upper strata router of router one is two of 2a and 2b, and the link that accompanies with described

upper strata router

2a and 2b also is two of 3a, 3b.Router one is set at link to the upper strata router with 3a, and 3b is set to the link that replaces the upper strata router.

Fig. 1 is the sequential chart of network integral body of the present invention.At this figure on last stage,

terminal

5a and 5b have carried out the transmission registration to the multileaving of router one, and router one has carried out the transmission registration to the multileaving of router two a.Under this state, when from the apply for information of router two a when link 3a arrives (S101a), router one is through link 3a response report message (S102a).Though apply for information also arrives (S101) from router two b through link 3b, owing in the router of the upper strata of present stage, do not have 2b, so do not respond report message (S102b).Though under this state, the multileaving message that sends from server 8 arrive through router 7, multileaving path 6 router two a, 2b both, but router-only 2a carries out the transmission of multileaving to router one, and

terminal

5a, 5b receive multileaving message (S103) through router one.Here, link 3a goes up and produces fault (S104).The router one that detects link failure is made interim report message according to the multileaving transmission registration situation of subordinate's terminal, and sends to router two b (S105) through link 3b.

Thus, the multileaving message transmission to router one becomes through router 2b (S106) from the router two a through S103.If under this state, inquiry arrives router one (S107) from router two b, and then router one is to router two b response report (S108).If, then detecting the router one making of link-recovery from link failure recovery (S109), link 3a represents that the IGMP disengaging group/MLD listener of multileaving group disengaging has finished message and (has been group disengaging report message under the situation of IGMPv3/MLDv2.Below, be called breakaway message), and send to router two b (S110) through link 3b.Meanwhile, according to the multileaving transmission registration situation of subordinate's terminal, make interim report message, and send to router two a (S111) through link 3a.Thus, identical to the multileaving dispense path of router one with S103, return to through router 2a (S112).In addition, in this example, carry out simultaneously transmit path is turned back to processing through router 2a, but thought before link 3b produces fault with the recovery of link 3a, also can be still through router 2b.At this moment, for fear of double registration, when link 3a recovers, breakaway message is sent to router two a.

Fig. 5 is the ideograph of internal structure of the router one of Fig. 4.Memory 11, CPU12 and line part 13 are connected by inner transport unit 14.The program and the required data of Route Selection that constitute router in memory 11, have been stored.In fact CPU12 is that Route Selection is carried out on the basis with program on the memory 11 and

data.Line part

13a, 13b and link 3,4 physical connections.Thus, stop up communicating by letter of router two and terminal 5 and router one from physical layer.Inner transport unit 14 is used bus or switch usually.There are various programs and data area in memory 11 inside.Only extracted the part of feature in the figure especially out.IGMP/MLD agency 111 is the programs that have the feature of router one, the actual IGMP/MLD agent processes of carrying out, and its result is written in the routing table 113.Routing protocol handling part 112 carries out the exchange of routing protocol message with near router, and its result is written in the routing table 113.ICP/IP protocol storehouse 114 is according to the data of routing table 113, actual transmission and terminal processes of carrying out the IP message.The state of 115 13a of monitoring wire portion of line management portion, 13b, and provide line state information to IGMP/MLD agency 111 or routing protocol handling part 112.Though handle these programs by CPU12 basically, be prepared as usually in recent years in the function of option table 113 and ICP/IP protocol storehouse 114 about the realization of the part that transmits and specially designed other processors, and handle at this.The 15th, the message transport processor.Have in inside and come to carry out very at high speed that message that simple transmission handles transmits engine 151 and the high function portion 152 of the complicated a little processing carrying out can not handling by the program of simplifying in 151, make up by it and carry out message and transmit.

Fig. 6 is the functional block diagram of IGMP/MLD Agent 111.Terminal management portion 1113 links to each other with terminal 5 with

line part

13a, 13b through ICP/IP protocol storehouse 114, after reception comes the report message and breakaway message of self terminal, writes the information that exists of terminal in group database 1111.In addition, serve as that the basis generates apply for information with the information of organizing database 1111, and regularly send to terminal.Upper strata link communication portion 1112 links to each other with router one 12 with line part 113 through ICP/IP protocol storehouse 114, by each group address get the group database 1111 information logic and, make towards the upper strata report message (fetch logic and the result for empty situation under, the situation that also has breakaway message), interim and send to the upper strata router as the response of apply for information.Which circuit is upper strata link information maintaining part 11121 in fact kept as the information of setting to the link of IGMP/MLD agency's upper strata router.

Further, in upper strata link communication portion 1112, have the upper strata link information maintaining part 11122 of replacement and upper strata link circuit monitoring unit 11123.Replace upper strata link information maintaining part 11122 to keep to the link information that replaces the upper strata router.Upper strata link circuit monitoring unit 11123 monitors the physical circuit information of the circuit that is set at the upper strata link, under the situation that has produced fault, replaces link to the upper strata router with the information that keeps in the link information maintaining part of replacement upper strata.Method as upper strata link circuit monitoring unit 11123 monitoring physical line informations, following method is arranged: regularly be set at line state information to the circuit of the link of upper strata router to 115 inquiries of line management portion, or in the line status information change situation under, to setting in the line management portion 115, to circulate a notice of.

Under the situation of this mode, though can not the possibility that can full out discover link failure be arranged corresponding to the fault on the IP layer of the fault of upper strata router self.

Fig. 9 is the example of the group database of Fig. 4.Member record is represented with the group of (multicast address, field pattern, source address list).In addition, it is corresponding to IGMPv3/MLDv2, and the field pattern is that " EXCLUDE ", the source address that does not comprise the implication of source address is " NULL " of the implication of sky among the IGMPv2/MLDv1.In the example of Fig. 4, multicast address is that 224.10.1.1, source address are (100.1.1.1), and the field pattern is " INCLUDE " that comprises the implication of source address, and the transmission destination becomes 1.1.1.2 and the 1.1.2.2 as the address of each terminal.

[embodiment 2]

The sequential of network configuration and network integral body is identical with embodiment 1.

Fig. 7 is the functional block diagram of IGMP/MLD Agent of the present invention, is the variation of the example of Fig. 6.Upper strata link communication portion has the upper strata link information maintaining part 11122 of replacement and upper strata link routing information monitoring unit 11124.Replace upper strata link information maintaining part 11122 to keep to the link information that replaces the upper strata router.OSPF that link Route Selection monitoring unit 11124 supervision in upper strata are moved on the circuit that is set at the upper strata link and the IP single-point of BGP transmit the link-state information that routing protocol had, under the situation that has produced fault, be used in the information that replaces keeping in the link information maintaining part of upper strata and replace link to the upper strata router.Monitor that as upper strata link routing information monitoring unit 11124 the IP single-point transmits the method for information, following method is arranged: to the routing state information of routing table 113 inquiry regularly as the link of setting to the link of upper strata router, perhaps under the situation that the routing state information of link has changed, on routing protocol handling part 112, set, to circulate a notice of.

Under the situation of this mode, since need be different with embodiment 1 transmit link that routing protocol the carries out judgment processing (adopt usually and suspend ( イ system アウト)) that opens circuit by single-point, expend time in so may compare with embodiment 1 in link failure is judged, but can be corresponding to the fault on the IP layer of the fault of upper strata router self.

[embodiment 3]

Fig. 8 is the functional block diagram of IGMP/MLD Agent of the present invention, is the variation of the example of Fig. 6.Have the upper strata of replacement link information maintaining part 11122 and inquiry watchdog timer 11125 in upper strata link communication portion.Replace upper strata link information maintaining part 11122 to keep to the link information that replaces the upper strata router.Inquiry watchdog timer 11125 timing are from the interval as the apply for information of the circuit of upper strata link setting, behind the process certain hour, under the situation that does not have to arrive at apply for information, regard as and produced fault, be used in the information that replaces keeping in the upper layer information maintaining part and replace link to the upper strata router.

Because the interval of apply for information judges that than being opened circuit by the common single-point transmission link that routing protocol carried out the spent time is long, so under the situation of this mode, may on link failure is judged, more expend time in than embodiment 2, but can produce fault on the special IP layer of fault corresponding to the multileaving function in the router of upper strata only.

In addition, the

foregoing description

1,2,3 is installed simultaneously, also can be corresponding to all situations.

In addition, in the above-described embodiments, illustrated handling the example that data built-in in memory and program are carried out Route Selection by CPU, but memory and CPU move as control device simultaneously, and software section also can be realized same function as hardware configuration.In addition, also can as previously mentioned the part of function be replaced with other special-purpose hardware and softwares (for example, the message transport processor 15).

Claims

1, a kind of IGMP/MLD agent router has: memory, storage upper strata link information and replacement upper strata link information; Processing unit carries out the control of Route Selection; Line part is connected with replacement upper strata link physical with the upper strata link, and communicates according to the control of above-mentioned processing unit; Inner transport unit connects above-mentioned memory, processing unit and line part, it is characterized in that:

Above-mentioned processing unit sends the IGMP/MLD report to above-mentioned replacement upper strata link under the situation of the fault that has detected above-mentioned upper strata link, afterwards, and by the inquiry of response from replacement upper strata link, the control of switching the upper strata router.

2, IGMP/MLD agent router according to claim 1 is characterized in that: above-mentioned processing unit detects link failure by the physical fault that detects upper strata link circuit.

3, IGMP/MLD agent router according to claim 1 is characterized in that: above-mentioned processing unit uses and the IP single-point transmission routing information of upper strata router detects link failure.

4, IGMP/MLD agent router according to claim 1 is characterized in that: under the situation that above-mentioned processing unit does not have to arrive at the IGMP/MLD apply for information from the upper strata router within a certain period of time, regard link failure as.

5, a kind of communicator comprises: control part, have memory and CPU, and carry out Route Selection control according to the information in the above-mentioned memory; Line part is connected with replacement upper strata link physical with the upper strata link; Inner transport unit interconnects above-mentioned memory, CPU and line part, it is characterized in that,

Above-mentioned control part has: the IGMP/MLD agency, carry out the IGMP/MLD agent processes; The routing protocol handling part carries out the exchange of routing protocol message with other communicators, and the walking along the street of going forward side by side is by selecting protocol processes; Routing table is stored the result of above-mentioned IGMP/MLD agent processes and the result that above-mentioned routing protocol is handled; The ICP/IP protocol storehouse according to the data of storing, carries out the transmission and the terminal processes of IP message in above-mentioned routing table; Line management portion monitors the state of above-mentioned line part, and provides line state information to above-mentioned IGMP/MLD agency and routing protocol handling part;

Above-mentioned IGMP/MLD agency has:

Terminal management portion is from the participation breakaway message of terminal reception to the multileaving group; The group database, the information of coming storage terminal according to the reception result of above-mentioned terminal management portion;

Upper strata link communication portion comprises: upper strata link information maintaining part keeps which circuit in fact as the information of setting to the link of IGMP/MLD agency's upper strata router; Upper strata link circuit monitoring unit monitors the physical circuit information of the circuit that is set at the upper strata link, and under the situation that has produced fault, will be used in the information that replaces keeping in the link information maintaining part of upper strata to the link of upper strata router and replace; Communicate with above-mentioned upper strata link or replacement upper strata link.

6, a kind of IGMP/MLD agent router has: control part, carry out Route Selection control; Line part is carried out physical connection with upper strata link and replacement upper strata link; Inner transport unit interconnects above-mentioned control part and line part,

Receive the IGMP/MLD message from terminal, and the IGMP/MLD message sent to the upper strata link as the agency of this terminal, carry out the Route Selection of multileaving message, it is characterized in that,

Above-mentioned control part has: terminal management portion, from the participation breakaway message of above-mentioned terminal reception to the multileaving group; The group database is according to the reception result of above-mentioned terminal management portion, the information of coming storage terminal; Upper strata link communication portion under the situation of the fault that detects above-mentioned upper strata link, sends the IGMP/MLD report to above-mentioned replacement upper strata link, afterwards, and by the inquiry of response from replacement upper strata link, the control of switching the upper strata link.

7, IGMP/MLD agent router according to claim 6 is characterized in that: described upper strata link communication portion detects link failure by detecting the physical fault of upper strata link circuit.

8, IGMP/MLD agent router according to claim 6 is characterized in that: the IP single-point of link communication portion use of described upper strata and upper strata router transmits routing information, detects link failure.

9, IGMP/MLD agent router according to claim 6 is characterized in that: under the situation that above-mentioned upper strata link communication portion does not have to arrive at the IGMP/MLD apply for information from the upper strata router within a certain period of time, regard link failure as.