Packetized content delivery apparatus and methods

1. A content delivery network, comprising:

a delivery cache in operable communication with a client device, the delivery cache configured to effectuate provision of content to the client device;

a first tier cache in operable communication with the delivery cache, the first tier cache configured to effectuate provision of the content to the delivery cache; and

a pool of active routes associated with at least one network address;

wherein:

the delivery cache is accessible by the client via any one of a range of Internet Protocol (IP) addresses;

the delivery cache is further configured to, upon detection of a failed route, effectuate withdrawal of the failed route from the pool of active routes based at least on a determination of the existence of an active route to prevent stranding of the at least one network address; and

the first tier cache is accessible by the delivery cache via any one of at least one subset range of the range of IP addresses.

2. The network of claim 1 , wherein:

the delivery cache is further configured to, based on the content being available at the delivery cache, provide the content to the client in response to receipt of a client request; and

the content provision to the client is characterized by an absence of a backfill of the content from the tier one cache to the delivery cache, subsequent to the request.

3. The network of claim 1 , wherein

the delivery cache is configured to, based on the content being not available at the delivery cache, provide the content to the client pursuant to a client request and to a content backfill operation conducted between the first tier cache and the delivery cache, the backfill operation conducted subsequent to and substantially in response to the request.

4. The network of claim 1 , further comprising:

another tier cache operative at a tier different than that associated with the first tier cache, the another tier cache in operable communication with the delivery cache, the another tier cache configured to effectuate provision of the content to the delivery cache;

wherein the delivery cache is configured to, based on the content being not available at the delivery cache, provide the content to the client pursuant to a client request and a content backfill operation between one of the first tier one cache or the another tier cache and the delivery cache performed subsequent to the request.

5. The network of claim 4 , wherein:

the first tier cache and another tier cache are configured to form a hierarchy characterized by at least two levels;

each of the IP addresses comprises 32 bits; and

the delivery cache is configured to perform the content backfill operation from the another tier cache without the another tier cache uploading the content into the first tier cache.

6. A non-transitory computer-readable apparatus configured to store one or more computer programs thereon, the one or more computer programs comprising a plurality of instructions configured to, when executed:

based on a request to withdraw an active route from a pool of active routes of a network, determine a network address associated with the route;

determine existence of another active route of the pool of active routes; and

effectuate withdrawal of the active route from the pool of active routes based at least on the determination of the existence of the another active route to prevent stranding of the network address;

wherein:

the active route and the another active route are configured to provide content associated with the network address to a client of the network; and

the determination of existence of the another active route is based at least on a match between the network address and an address of the another route within the network.

7. The apparatus of claim 6 , wherein:

the active route is associated with a first node of the network providing the content to the client prior to the request; and

the withdrawal of the active route is characterized by a termination of the content provision by the first node to the client via the active route.

8. The apparatus of claim 7 , wherein the another active route is associated with a second node of the network, the first and the second nodes being addressable by the client via the address of the network.

9. The apparatus of claim 6 , wherein the one or more programs are further configured to, based on a determination that no other active route associated with the address exists, retain the active route within the pool of active routes, the retaining of the active route characterized by continuing provision of the content to the client.

10. The apparatus of claim 6 , wherein the content comprises a sequence of data packets associated with: (i) provision of video on demand content; (ii) provision of broadcast content; (iii) an operation of a visual communications service; and/or (iv) interactive application characterized by one or more client inputs.

11. The apparatus of claim 6 , wherein the pool of active routes is configured to be advertised.

12. The apparatus of claim 6 , wherein the plurality of instructions are further configured to, when executed and based at least on a selection of a given route of the pool of active routes, cause delivery of the content to the client via a node of a plurality of nodes associated with the pool of active routes, the given route comprising the node.

13. The apparatus of claim 12 , wherein the selection of the given route is conducted in accordance with a routing rule based at least on one of: (i) node load, (ii) route available bandwidth, and (iii) service level associated with the client.

14. The apparatus of claim 13 , wherein:

the routing rule is further based on a proximity measure between the client and the node, the node characterized by a first distance to the client that is shorter than a second distance between the client and another one of the two or more nodes.

15. The apparatus of claim 6 , wherein:

the association of the content with the address is based at least on a distribution of a list of valid addresses provided to the client after authentication of the client to the network.

16. The apparatus of claim 6 , wherein the association of the content with the address is based at least on a domain name system protocol.

17. The apparatus of claim 6 , wherein at least a portion of the network comprises a packet network configured to deliver the content over an Internet Protocol television (IPTV) service.

18. The apparatus of claim 17 , wherein the content comprises linear content.

19. The apparatus of claim 6 , wherein the plurality of instructions are further configured to, when executed, cause provision via a delivery cache of the content to the client, the causation of provision substantially in response to a client request and based at least in part on the content being available at a delivery cache;

wherein the content provision to the client comprises at least one content backfill operation performed between a first tier cache and the delivery cache.

20. A method of operating a packet-enabled content distribution network so as to prevent stranding of a network address, the method comprising:

based at least on a request to withdraw an active route from a pool of active routes of the network, determining a network address associated with the active route;

determining an existence of at least one other active route of the pool of active routes, the at least one other active route also comprising the network address and capable of providing content associated with the network address to a client device of the network; and

effectuating withdrawal of the active route from the pool of active routes based at least on the determination of the existence of the at least one other active route.

21. The method of claim 20 , wherein the at least one other active route is associated with a node of the network, the node being addressable by the client device via the network address.

22. The method of claim 20 , further comprising retaining, based at least on a determination that no other active route associated with the address exists, the active route within the pool of active routes, the retaining of the active route enabling continued provision of the content to the client.

23. The method of claim 22 , wherein the provision of the content comprises providing a sequence of data packets associated with real-time content, and the retaining of the active route prevents interruptions of delivery of the real-time content.

24. The method of claim 20 , further comprising advertising the pool of active routes to one or more client devices of the network.

25. The method of claim 20 , further comprising instituting use of the at least one other active route for delivery of the content prior to said effectuating, and wherein the method is performed substantially automatically in the event of detection of a failure of the active route.

26. The method of claim 20 , wherein the at least one other active route comprises a plurality of other active routes, and the method further comprises selection of a given route in accordance with a routing rule based on one or more of: (i) service level associated with the client device, (ii) content encoding rate, and/or (iii) resolution of a display apparatus associated with the client.

27. The method of claim 20 , wherein the at least one other active route comprises a plurality of other active routes, and the method further comprises selection of one of the plurality of other routes based at least on a proximity measure between the client device and a network node.