Control plane architecture for multicast cache-fill

1. A method, comprising:

receiving, by a gateway device, a multicast listing identifying content items available for multicast reception;

receiving a content request from a consumption device, the content request being a request to establish a unicast session to obtain requested content;

determining that the requested content is listed in the multicast listing;

joining a multicast group identified in the multicast listing;

supplying the requested content from the multicast group to the consumption device in response to the consumption device's content request;

receiving a content request for a second item of content from the consumption device;

determining that a requested version of the second item of content is not listed in the multicast listing;

determining that a similar version of the second item of content is listed in the multicast listing;

transmitting a message to the consumption device, informing the consumption device that the similar version is available; and

receiving approval from the consumption device to supply the similar version of the second item of content instead of the requested version of the second item of content.

2. The method of claim 1 , further comprising:

while supplying the requested content to the consumption device, the gateway device switching from the multicast group to a unicast transmission for the requested content without further input from the consumption device, and without informing the consumption device of the switching.

3. The method of claim 1 , further comprising:

the gateway device remaining a member of the multicast group after determining that the consumption device no longer needs the requested content.

4. The method of claim 3 , wherein if the consumption device does not resume consumption of the requested content within a predetermined period of time, the gateway device leaves the multicast group.

5. The method of claim 4 , further comprising storing parameters identifying different lengths of time to be used as the predetermined period of time for different programs or services.

6. The method of claim 3 , further comprising, after determining that the consumption device no longer needs the requested content, remaining a member of the multicast group for an amount of time that depends on a user preference corresponding to the requested content or a service offering the requested content.

7. The method of claim 3 , further comprising the gateway device remaining a member of the multicast group of the requested content and storing portions of the requested content received while the consumption device needs the requested content, and after the consumption device no longer needs the requested content, remaining a member of the multicast group without storing portions of the requested content received while the consumption device no longer needs the requested content.

8. A method, comprising:

receiving, at a gateway device, a multicast listing identifying content items available for multicast reception;

receiving a unicast content request from a consumption device, the unicast content request being a request to establish a unicast session to obtain content;

determining that the requested content is listed in the multicast listing;

subscribing to a multicast group identified in the multicast listing;

supplying the requested content from the multicast group to the consumption device in response to the consumption device's unicast content request; and

conducting a cache join of the multicast group upon the consuming device ceasing to access the requested content in the multicast group, wherein the cache join includes remaining a member of the multicast group without caching content from the multicast group.

9. The method of claim 8 , further comprising:

while supplying the requested content to the consumption device, switching from the multicast group to a unicast transmission for the content without further input from the consumption device, and without informing the consumption device of the switching.

10. The method of claim 8 , further comprising:

receiving a unicast content request for a second item of content from the consumption device;

determining that a requested version of the second item of content is not listed in the multicast listing;

determining that a similar version of the second item of content is listed in the multicast listing;

transmitting a message to the consumption device, informing the consumption device that the similar version is available; and

receiving approval from the consumption device to supply the similar version of the second item of content instead of the requested version of the second item of content.

11. The method claim 10 , further comprising selecting the similar version based on available bandwidth between the computing device and a termination system.

12. The method of claim 8 , further comprising:

remaining a member of the multicast group after determining that the consumption device no longer needs the requested content.

13. The method of claim 12 , further comprising:

leaving the multicast group if the consumption device does not resume consumption of the requested content within a predetermined period of time.

14. The method of claim 8 , further comprising managing bandwidth usage by adjusting multicast sessions.

15. A method, comprising:

receiving, by a gateway device, a multicast listing identifying content items available for multicast reception;

receiving a content request from a consumption device, the content request being a request to establish a unicast session to obtain requested content;

determining that the requested content is listed in the multicast listing;

joining a multicast group identified in the multicast listing;

supplying the requested content from the multicast group to the consumption device in response to the consumption device's content request; and

the gateway device remaining a member of the multicast group after determining that the consumption device no longer needs the requested content.

16. The method of claim 15 , further comprising:

while supplying the requested content to the consumption device, switching from a multicast group to a unicast transmission for the content without further input from the consumption device, and without informing the consumption device of the switching.

17. The method of claim 15 , further comprising:

receiving a content request for a second item of content from the consumption device;

determining that a requested version of the second item of content is not listed in the multicast listing;

determining that a similar version of the second item of content is listed in the multicast listing;

transmitting a message to the consumption device, informing the consumption device that the similar version is available; and

receiving approval from the consumption device to supply the similar version of the second item of content instead of the requested version of the second item of content.

18. The method of claim 15 , further comprising:

leaving the multicast group if the consumption device does not resume consumption of the requested content within a predetermined period of time.

19. The method of claim 18 , wherein the predetermined period of time is a user-configured parameter.