Data transfer apparatus and multicast system

• US 20060176804A1
• Filed: 08/17/2005
• Published: 08/10/2006
• Est. Priority Date: 02/04/2005
• Status: Abandoned Application

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Shibata, Takeshi
• Application Number:
  US11/205,170
• Publication Number:
  US 20060176804A1
• Time in Patent Office: Days
• US Class Current: 370/217
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• CPC Class Codes: H04L 12/1863 comprising mechanisms for improved reliability, e.g. status reports arrangements for detecting or preventing errors by carrying supervisory signal the return channel H04L1/16
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/16 Multipoint routing
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/28 using route fault recovery

Abstract

By transmitting/receiving a multicast receiving terminal management message, a router to be a starting point upon creation of a multicast route is determined based on a multicast routing protocol, and switched according to a state of a multicast transmitting terminal side network. Accordingly, when a trouble occurs in the transmitting terminal side network, it becomes possible to perform switching into a redundant network.

Claims

1. A data transfer apparatus, capable of transferring multicast data, which is connected to a terminal for transmitting multicast data, a terminal for receiving multicast data, and another data transfer apparatus forming redundant topology with the data transfer apparatus, comprising:

an interface for transmitting/receiving data; and

a transfer processing unit for performing a transfer processing on data received from the interface,

wherein, when a trouble occurs in a network between the terminal for transmitting multicast data and the interface or a network between the terminal for receiving multicast data and the interface, a distribution route for multicast data is switched into a route passing the another multicast data transfer apparatus by the data transfer apparatus that stops a function of becoming a representative router for multicast data or lowers a priority for becoming a representative router for multicast data.

2. The data transfer apparatus according to claim 1, wherein, when stopping the function of becoming a representative router for multicast data, the data transfer apparatus executes at least one of processings of:

stopping transmission of one of a control message for a multicast routing protocol and a control message for a multicast terminal management protocol; and

transmitting one of a specific control message for a multicast routing protocol and a specific control message for a multicast terminal management protocol.

3. The data transfer apparatus according to claim 2, wherein the specific control message includes information indicating that the data transfer apparatus is to end being a representative for multicast routing or multicast terminal management.

4. The data transfer apparatus according to claim 1, wherein, when lowering the priority for becoming a representative router for multicast data, the data transfer apparatus of transmits a specific control message for a multicast routing protocol or a specific control message for a multicast terminal management protocol.

5. The data transfer apparatus according to claim 4, wherein the specific control message includes information indicating a lowered priority for becoming a representative for multicast routing or multicast terminal management.

6. The data transfer apparatus according to claim 1, wherein a trouble is detected in a network connected to the interface based on at least one of an electric trouble in the interface, a trouble of a unicast routing processing in the interface, or a trouble of a multicast routing processing in the interface.

7. The data transfer apparatus according to claim 1, wherein, when a trouble occurs in the network between the terminal for transmitting multicast data and the interface or the network between the terminal for receiving multicast data and the interface, the trouble is detected based on one of detection that at least one of other data transfer apparatuses, which are connected between a portion in which the trouble has occurred and the data transfer apparatus, has not transmitted a control message for a multicast routing protocol or a control message for a multicast terminal management protocol for a predetermined period, and detection that the at least one of other data transfer apparatuses has transmitted a specific control message for a multicast routing protocol or a specific control message for a multicast terminal management protocol.

8. The data transfer apparatus according to claim 1, wherein, when becoming a representative for multicast receiving terminal management by transmitting/receiving a control message for a multicast receiving terminal management protocol to/from the at least one of other data transfer apparatuses, the data transfer apparatus also becomes a representative for multicast routing.

9. The data transfer apparatus according to claim 1, wherein, when not becoming a representative for multicast receiving terminal management by transmitting/receiving a control message for a multicast receiving terminal management protocol to/from the at least one of other data transfer apparatuses, the data transfer apparatus does not become a representative for multicast routing.

10. The data transfer apparatus according to claim 8, wherein:

when the data transfer apparatus becomes the representative for multicast receiving terminal management and the representative for multicast routing, and when the data transfer apparatus receives a request to transmit multicast data based on a multicast terminal management protocol from the terminal for receiving multicast data, the data transfer apparatus;

transmits a request to transmit multicast data based on a multicast routing protocol from the interface; and

creates a multicast routing table for specifying a transfer route for multicast data.

11. The data transfer apparatus according to claim 8, wherein:

when the data transfer apparatus becomes the representative for multicast receiving terminal management and the representative for multicast routing, and when the data transfer apparatus receives a request to transmit multicast data based on a multicast terminal management protocol from the terminal for receiving multicast data, the data transfer apparatus;

transmits a request to stop multicast data based on a multicast routing protocol from the interface; and

deletes a multicast routing table for specifying a transfer route for multicast data.

12. The data transfer apparatus according to claim 1, wherein, when a trouble occurs in a network connected to the interface, a distribution route for multicast data is switched into a route passing the another multicast data transfer apparatus by the data transfer apparatus that stops a function as a representative for multicast receiving terminal management or transmits data including information indicating a lowered priority as a representative for multicast receiving terminal management.

13. The data transfer apparatus according to claim 1, wherein, when a trouble occurs in a network connected to the interface, a distribution route for multicast data is switched into a route passing the another multicast data transfer apparatus by the data transfer apparatus that stops a function as a representative for multicast routing or transmits data including information indicating a lowered priority as a representative for multicast routing.

14. The data transfer apparatus according to claim 1, wherein, when the data transfer apparatus becomes the representative for multicast receiving terminal management and the representative for multicast routing, and when a trouble occurs in a network connected to the interface, a distribution route for multicast data is switched into a route passing the another multicast data transfer apparatus by the data transfer apparatus that stops a function as a representative for multicast terminal management or transmits data including information indicating a lowered priority as a representative for multicast terminal management.

15. The data transfer apparatus according to claim 1, which is connected to further another data transfer apparatus for distributing multicast data to be transmitted to a terminal for receiving the multicast data from one of the data transfer apparatus and the another data transfer apparatus,

wherein, when a trouble occurs between the further another data transfer apparatus and the interface, a distribution route for multicast data is switched into a route passing the another multicast data transfer apparatus by the data transfer apparatus that stops a function as a representative for multicast routing or transmits data including information indicating a lowered priority as a representative for multicast routing.

16. A multicast system, comprising:

a terminal for transmitting multicast data;

a terminal for receiving multicast data; and

a plurality of data transfer apparatuses, capable of transferring multicast data, which are each connected to a link of a terminal for receiving multicast data and a terminal for transmitting multicast data,

the plurality of data transfer apparatuses each comprising;

an interface for transmitting/receiving multicast data; and

a transfer processing unit for performing a transfer processing on data received from the interface, wherein;

one data transfer apparatus is a data transfer apparatus to be a representative for a representative router for multicast data in the link of the terminal for receiving multicast data, and forms redundant topology with the other data transfer apparatuses; and

when a trouble occurs in a portion of a network made redundant between the terminal for transmitting multicast data and the interface of a data transfer apparatus to be the representative, a distribution route for multicast data is switched into a route passing the another multicast data transfer apparatus by the one data transfer apparatus that stops a function of becoming a representative router for multicast data in the link of the terminal for receiving multicast data or lowers a priority for becoming a representative router for multicast data.

17. A multicast system, comprising:

a terminal for transmitting multicast data;

a terminal for receiving multicast data;

a plurality of data transfer apparatuses, capable of transferring multicast data, which are each connected to a link of a terminal for transmitting multicast data and a terminal for receiving multicast data; and

another data transfer apparatus for transferring multicast data, which is connected between at least one of the plurality of data transfer apparatuses and the terminal for receiving multicast data,

the plurality of data transfer apparatuses and the another data transfer apparatus each comprising;

an interface for transmitting/receiving multicast data; and

a transfer processing unit for performing a transfer processing on data received from the interface, wherein;

one data transfer apparatus is a data transfer apparatus to be a representative for a representative router for multicast data in the link of the terminal for transmitting multicast data, and forms redundant topology with the other data transfer apparatuses; and

when a trouble occurs in a portion of a network made redundant between the another data transfer apparatus and the interface of a data transfer apparatus to be the representative, a distribution route for multicast data is switched into a route passing the another multicast data transfer apparatus by the one data transfer apparatus that stops a function of becoming a representative router for multicast data in the link of the terminal for receiving multicast data or lowers a priority for becoming a representative router for multicast data.

18. A program executable by a data transfer apparatus, capable of transferring multicast data, which is connected to a link of a terminal for receiving multicast data, a terminal for transmitting multicast data, and at least another data transfer apparatus made redundant, the program being capable of executing a multicast route switching method comprising the steps of:

detecting a trouble that occurs in a portion of a network made redundant with the terminal for transmitting multicast data; and

stopping, by the data transfer apparatus, a function of becoming a representative router for multicast data in the link of the terminal for receiving multicast data or lowering a priority for becoming a representative router for multicast data.

19. A program executable by a data transfer apparatus, capable of transferring multicast data, which is connected to a link of a terminal for transmitting multicast data, a terminal for receiving multicast data, and at least another data transfer apparatus made redundant, the program being capable of executing a multicast route switching method comprising the steps of:

detecting a trouble that occurs in a portion of a network made redundant with further another data transfer apparatus for transferring multicast data; and

stopping, by the data transfer apparatus, a function of becoming a representative router for multicast data in the link of the terminal for transmitting multicast data or lowering a priority for becoming a representative router for multicast data.