MULTICAST SOURCE IN GROUP ADDRESS MAPPING

• US 20140052831A1
• Filed: 08/17/2012
• Published: 02/20/2014
• Est. Priority Date: 08/17/2012
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Wijnands, Ijsbrand, Shepherd, Gregory J.
• Granted Patent: US 9,363,227 B2
• Time in Patent Office: Days
• US Class Current: 709/220
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• CPC Class Codes: H04L 12/1854 with non-centralised forwarding system, e.g. chaincast
• CPC Class Codes: H04L 2101/604 Address structures or formats
• CPC Class Codes: H04L 45/16 Multipoint routing
• CPC Class Codes: H04L 61/25 of the same type

Abstract

The present disclosure provides a source specific multicast service that maps multicast group addresses to corresponding source addresses. A boundary routing element can be configured to determine whether a received join request includes a mapped group address. If the join request does not include a mapped group address, boundary routing element can be configured to perform normal join request processing of the join request. If the join request includes a mapped group address, the boundary routing element can be configured to generate a corresponding source address using the mapped group address. The boundary routing element can also be configured to perform alternative join request processing as if the join request were an SSM join request that specified both a source address and a multicast group address.

Claims

1. A method comprising:

receiving a join request from a receiver, wherein

the join request comprises a group address;

determining whether the group address requires source address generation; and

in response to a determination that the group address requires source address generation, generating a source address, wherein

the group address is used to generate the source address.

2. The method of claim 1, wherein

the determining further comprises

comparing the group address with a prefix list, and

the determination that the group address requires source address generation is made in response to the group address matching a prefix in the prefix list.

3. The method of claim 1, wherein

the generating the source address further comprises

combining one or more pre-configured octet values with one or more octets of the group address, and

the combining produces the source address.

4. The method of claim 3, wherein

the combining is performed according to an octet assignment,

the octet assignment assigns the one or more pre-configured octet values to one or more higher order octets of the source address, and

the octet assignment assigns the one or more octets of the group address to one or more lower order octets of the source address.

5. The method of claim 3, further comprising:

selecting the one or more pre-configured octet values from a selector table, wherein

at least one octet of the group address is used to select the one or more pre-configured octet values.

6. The method of claim 1, further comprising:

performing specific source multicast processing, using the source address and the group address, wherein

a source corresponding to the source address is configured to provide a datastream to the group address on a channel,

the source address and the group address together uniquely identify the channel, and

the performing the specific source multicast processing subscribes the receiver to the channel.

7. The method of claim 1, wherein the group address is a source specific multicast group address.

8. The method of claim 1, wherein the receiver does not support source specific multicast.

9. A boundary routing element comprising:

a port configured to receive a join request from a receiver, wherein the join request comprises a group address;

a routing module configured to

determine whether the group address requires source address generation; and

a source address generator configured to

generate a source address, in response to a determination that the group address requires source address generation, wherein the group address is used to generate the source address.

10. The boundary routing element of claim 9, wherein

the routing module is further configured to

compare the group address with a prefix list, and

the determination that the group address requires source address generation is made in response to a match of the group address with a prefix in the prefix list.

11. The boundary routing element of claim 9, wherein

the source address generator is further configured to

combine one or more pre-configured octet values with one or more octets of the group address to produce the source address.

12. The boundary routing element of claim 11, wherein

the one or more pre-configured octet values with one or more octets of the group address are combined according to an octet assignment,

the octet assignment assigns the one or more pre-configured octet values to one or more higher order octets of the source address, and

the octet assignment assigns the one or more octets of the group address to one or more lower order octets of the source address.

13. The boundary routing element of claim 11, wherein

the source address generator is further configured to

select the one or more pre-configured octet values from a selector table, wherein

at least one octet of the group address is used to select the one or more pre-configured octet values.

14. The boundary routing element of claim 9, wherein

the routing module is further configured to

perform specific source multicast processing, using the source address and the group address, wherein

a source corresponding to the source address is configured to provide a datastream to the group address on a channel,

the source address and the group address together uniquely identify the channel, and

the performing the specific source multicast processing subscribes the receiver to the channel.

15. A non-transitory computer readable storage medium configured to store program instructions that, when executed on a processor, are configured to cause the processor to perform a method comprising:

receiving a join request from a receiver, wherein the join request comprises a group address;

determining whether the group address requires source address generation; and

in response to a determination that the group address requires source address generation, generating a source address, wherein

the group address is used to generate the source address.

16. The non-transitory computer readable storage medium of claim 15, wherein

the determining further comprises

comparing the group address with a prefix list, and

the determination that the group address requires source address generation is made in response to the group address matching a prefix in the prefix list.

17. The non-transitory computer readable storage medium of claim 15, wherein

the generating the source address further comprises

combining one or more pre-configured octet values with one or more octets of the group address, and

the combining produces the source address.

18. The non-transitory computer readable storage medium of claim 17, wherein

the combining is performed according to an octet assignment,

the octet assignment assigns the one or more pre-configured octet values to one or more higher order octets of the source address, and

the octet assignment assigns the one or more octets of the group address to one or more lower order octets of the source address.

19. The non-transitory computer readable storage medium of claim 17, wherein the method further comprises:

selecting the one or more pre-configured octet values from a selector table, wherein

at least one octet of the group address is used to select the one or more pre-configured octet values.

20. The non-transitory computer readable storage medium of claim 15, wherein the method further comprises:

performing specific source multicast processing, using the source address and the group address, wherein

a source corresponding to the source address is configured to provide a datastream to the group address on a channel,

the source address and the group address together uniquely identify the channel, and

the performing the specific source multicast processing subscribes the receiver to the channel.