Application driven fast unicast flow replication

• US 20070058629A1
• Filed: 09/06/2006
• Published: 03/15/2007
• Est. Priority Date: 09/09/2005
• Status: Active Grant

• Current Assignee: Tellabs Communications Canada Ltd. (Infinera Corp.)
• Original Assignee: Zeugma Systems Canada, Inc.
• Inventors: Luft, Siegfried
• Granted Patent: US 7,719,995 B2
• Time in Patent Office: Days
• US Class Current: 370/390
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• CPC Class Codes: H04L 65/612 for unicast
• CPC Class Codes: H04L 67/01 Protocols
• CPC Class Codes: H04L 67/56 Provisioning of proxy services store-and-forward switching systems in data switching networks H04L12/54
• CPC Class Codes: H04L 67/566 Grouping or aggregating service requests, e.g. for unified processing
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching

Abstract

A technique to replicate unicast flows is described. A plurality of unicast control flows are received at a network element from a plurality of clients. One of the unicast control flows is forwarded to a server. A unicast content flow is received from the server at the network element in response to forwarding the one of the unicast control flows. The unicast content flow is replicated at the network element as a plurality of replicated unicast content flows for transmission to the plurality of clients.

Claims

1. A method comprising:

receiving a plurality of unicast control flows at a network element from a plurality of clients;

forwarding one of the unicast control flows to a server;

receiving a unicast content flow from the server at the network element in response to forwarding the one of the unicast control flows; and

replicating the unicast content flow at the network element as a plurality of replicated unicast content flows for transmission to the plurality of clients.

2. The method of claim 1, wherein the network element comprises an application aware router capable of terminating the unicast control flows at an application layer and capable of interpreting application layer data within the unicast control flows.

3. The method of claim 1, wherein the plurality of unicast control flows each include source and destination addresses identifying a corresponding one of the plurality of clients and the server, respectively, the method further comprising:

terminating the plurality of unicast control flows addressed to the server at the network element;

generating a list of the plurality of unicast control flows requesting content from the server; and

queuing redundant requests for the content after forwarding one of the requests to the server.

4. The method of claim 3, wherein replicating the unicast content flow as the plurality of replicated unicast content flows comprises:

copying payload data containing the content received from the server at the network element into packets of the plurality of replicated content flows;

generating new destination address data addressing corresponding ones of the plurality of clients for each of the queued requests; and

inserting the new destination address data into the packets of the replicated unicast content flows.

5. The method of claim 1, wherein the unicast control flows include control signals from client-side applications executing on the plurality of clients, the control signals requesting media content from a server-side application executing on the server, and wherein the unicast content flow received from the server includes the media content.

6. The method of claim 5, wherein the media content comprises a key frame of a video image for Internet Protocol (“

IP”

) television (“

IPTV”

).

7. The method of claim 6, wherein the server comprises a regional or local server, the method further comprising:

forwarding a first multicast broadcast for a first channel from an IPTV server to the plurality of clients,

wherein receiving the plurality of unicast control flows includes receiving the plurality of unicast control flows in response to a commercial insertion trigger identifying a commercial break in the first channel, the unicast control flows requesting a channel change to a second channel to receive regional or local commercials during the commercial break, and

wherein the unicast content flow comprises a burst of media content from the regional or local server to enable the plurality of clients to sync up with a second multicast broadcast from the IPTV server for the second channel.

8. A machine-accessible medium that provides instructions that, if executed by a machine, will cause the machine to perform operations comprising:

receiving a plurality of unicast control flows at a network element from a plurality of clients;

forwarding one of the unicast control flows to a server;

receiving a unicast content flow from the server at the network element in response to forwarding the one of the unicast control flows; and

replicating the unicast content flow at the network element as a plurality of replicated unicast content flows for transmission to the plurality of clients.

9. The machine-accessible medium of claim 8, further providing instructions that, if executed by the machine, will cause the machine to perform further operations, comprising:

interpreting application layer data within the unicast control flows; and

terminating the unicast control flows at an application layer in the network element.

10. The machine-accessible medium of claim 8, the machine-accessible medium further providing instructions that, if executed by the machine, will cause the machine to perform further operations, comprising:

terminating the plurality of unicast control flows addressed to the server at the network element;

generating a list of the plurality of unicast control flows requesting identical content from the server; and

queuing requests for the identical content after forwarding one of the requests to the server.

11. The machine-accessible medium of claim 10, wherein replicating the unicast content flow as the plurality of replicated unicast content flows comprises:

copying payload data containing the identical content received from the server at the network element into packets of the plurality of replicated content flows;

generating new destination address header data addressing corresponding ones of the plurality of clients for each of the queued requests; and

inserting the new destination address header data into the packets of the replicated unicast content flows.

12. The machine-accessible medium of claim 8, wherein the unicast control flows include control signals from client-side applications executing on the plurality of clients, the control signals requesting media content from a server-side application executing on the server, and wherein the unicast content flow received from the server includes the media content.

13. The machine-accessible medium of claim 12, wherein the media content comprises a key frame of a video image for Internet Protocol (“

IP”

) television (“

IPTV”

).

14. The machine-accessible medium of claim 13, wherein the server comprises a regional or local server, the machine-accessible medium further providing instructions that, if executed by the machine, will cause the machine to perform further operations, comprising:

forwarding a first multicast broadcast for a first channel from an IPTV server to the plurality of clients,

wherein receiving the plurality of unicast control flows includes receiving the plurality of unicast control flows in response to an insertion point trigger identifying a commercial break in the first channel, the unicast control flows requesting a channel change to a second channel to receive regional or local commercials during the commercial break, and

wherein the unicast content flow comprises a burst of media content from the regional or local server to enable the plurality of clients to synch up with a second multicast broadcast from the IPTV server.

15. A network element, comprising:

a chassis including an interconnect;

at least one traffic module installed in the chassis and coupled to the interconnect;

at least one compute module installed in the chassis and coupled to the interconnect; and

software components distributed across the traffic and compute modules, the software components to execute on processing elements of the traffic and compute modules to perform operations including;

receive a unicast content flow from a server addressed to a network client;

classify packets of the unicast content flow to identify an application associated with the unicast content flow; and

replicate the unicast content flow to other clients identified in a list.

16. The network element of claim 15 including further software components to perform operations including:

intercept unicast control flows addressed to the server from the other clients, the unicast control flows including redundant requests for content previously requested by the network client;

terminate the unicast control flows at the network element; and

generate the list based at least in part on the redundant requests of the terminated unicast control flows.

17. The network element of claim 16, wherein the software components to intercept the unicast control flows addressed to the server from the other clients include software components to classify and interpret packets of the intercepted unicast control flows at an application layer protocol.

18. The network element of claim 15, wherein the network element comprises an application aware router, and wherein the application aware router includes an application for terminating unicast control flows from the client.

19. The network element of claim 18, wherein the application mimics server-side application functionality of the server transparently to the client.

20. A method, comprising:

receiving a unicast content flow from a server addressed to a network client;

classifying packets of the unicast content flow to identify an application associated with the unicast content flow; and

replicating the unicast content flow to other clients identified in a list.

21. The method of claim 20, further comprising:

intercepting unicast control flows addressed to the server from the other clients, the unicast control flows including redundant requests for content previously requested by the network client;

terminating the unicast control flows at the network element; and

generating the list based at least in part on the redundant requests of the terminated unicast control flows.

22. The method of claim 21, wherein intercepting the unicast control flows addressed to the server from the other clients includes classifying and interpreting packets of the intercepted unicast control flows at an application layer protocol.

23. The method of claim 20, wherein the unicast content flow includes at least one video content, audio content, or Internet Protocol Television (“

IPTV”

) content.

24. The method of claim 20, wherein classifying packets of the unicast content flow to identify the application associated with the unicast content flow comprises:

executing a preliminary classification of the packets received on a data path to determine whether additional classification should be executed; and

replicating the packets to a compute path to perform additional application layer classification while the packets continue along the data path, if the preliminary classification indicated to do so.