METHODS AND APPARATUS FOR MANAGING MULTICAST TRAFFIC THROUGH A SWITCH

• US 20110058548A1
• Filed: 07/29/2010
• Published: 03/10/2011
• Est. Priority Date: 02/01/2008
• Status: Active Grant

• Current Assignee: Media Patents S.L.
• Original Assignee: Media Patents S.L.
• Inventors: Fernández Gutiérrez, Alvaro
• Granted Patent: US 8,565,140 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 12/1886 with traffic restrictions for efficiency improvement, e.g. involving subnets or subdomains
• CPC Class Codes: H04L 49/201 Multicast operation; Broadcast operation
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches

Abstract

A method for managing multicast traffic through a switch operating in the layer 2 of the OSI model, and routers and switches involved in the method. In one implementation a router sends to a switch a message containing identification of specific equipment which has requested specific multicast traffic, and also containing a specification of the specific traffic, and when the switch receives data carrying multicast traffic, based on the destination and origin addresses of the data, and based on the identification of the specific equipment and of the specification of the specific multicast traffic that it has received in the message, the switch deduces if the data carry the specific traffic that has been requested by the specific equipment, and decides through which of its ports it transmits the data.

Claims

1-16. -16. (canceled)

17. A method for managing multicast traffic through a switch operating in the layer 2 of the OSI (Open Systems Interconnection) model, characterized in that a router that has received from specific equipment, which can be a host or another router, a request for a specific multicast traffic, sends to a switch, connected to the network interface of said router through which said router has received said request, a message containing an identification of said specific equipment and a specification of said specific multicast traffic;

and in that when said switch receives through one of its ports data carrying multicast traffic, said switch, based on the destination and origin addresses of said data carrying multicast traffic, and based on said identification of the specific equipment and on said specification of the specific multicast traffic which said router has sent to said switch by means of said message, deduces if said data carries said specific traffic which has been requested by said specific equipment, and said switch decides through which of its ports it transmits said data.

18. A method according to claim 17, characterized in that said specification of multicast traffic contained in said message which the router sends to the switch comprises information as to the sources the traffic of which has been requested by said specific equipment.

19. A method according to claim 18, characterized in that said router stores in specific records, for each of its network interfaces and for each equipment and multicast group, information as to the sources the traffic of which has been requested by said equipment;

said switch stores in corresponding specific records, for each equipment and multicast group, the information as to the sources the traffic of which has been requested by said equipment; and

said specific records of the switch are updated when such switch receives one of said messages sent by said router.

20. A method according to claim 19, characterized in that said messages sent by said router to said switch separately contain, for each specific equipment:

included source lists of a multicast group, indicating that said specific equipment wishes to receive the traffic sent by said included sources;

excluded source lists of a multicast group, indicating that said specific equipment wishes to receive the traffic sent by all the sources of said multicast group except said excluded sources; and

said specific records stored in said router and in said switch separately contain, for each specific equipment and multicast group, the data of said included sources and the data of said excluded sources.

21. A method according to claim 17, characterized in that said message which said router sends to said switch is encapsulated in IP data packets.

22. A method according to claim 17, characterized in that said identification of the specific equipment contained in the message which said router sends to said switch comprises the IP address of said specific equipment.

23. A method according to claim 22, characterized in that said switch receiving said message executes the ARP (Address Resolution Protocol) protocol for associating a MAC address to said IP address of the specific equipment.

24. A method according to claim 17, characterized in that said identification of the specific equipment contained in the message which said router sends to said switch comprises the MAC address of said specific equipment.

25. A method according to claim 17, characterized in that said identification of the specific equipment contained in the message which said router sends to said switch comprises the IP address and also the MAC address of said specific equipment.

26. A method according to claims 17, characterized in that said messages which said router sends to said switch are layer 3 messages in the OSI (Open Systems Interconnection) model and when said switch receives data through one of its ports said switch analyzes the destination address of said data in order to find out if said data carries one of said messages sent by said router and if it does said switch does not transmit said data but rather it processes it in order to read said message.

27. A method according to claim 17, characterized in that when a switch is connected to several routers, in order to prevent said routers from sending to said switch said messages with redundant information, each of said routers only sends said messages to the switch if it is in one of the two following cases:

said router transmits the traffic of a multicast channel to the switch;

said router receives requests for traffic of a multicast channel sent by a source which is connected to said router through said switch.

28. A router compatible with the method according to claim 17, characterized in that it stores executable instructions for, after receiving from a specific equipment, which can be a host or another router, a request for specific multicast traffic, sending to a switch, connected to the network interface of said router through which said router has received said request, a message containing an identification of said specific equipment and a specification of said specific multicast traffic.

29. A router according to claim 28, characterized in that it stores executable instructions for including in said message it sends to the switch said specification of multicast traffic, which comprises information about the sources the traffic of which has been requested by said equipment specific.

30. A router according to claim 29, characterized in that it stores executable instructions for storing in specific records, for each of its network interfaces and for each equipment and multicast group, information about the sources the traffic of which has been requested by said equipment.

31. A router according to claim 30, characterized in that it stores executable instructions for including in said messages it sends to the switch, separately and for each specific equipment:

—

included source lists of a multicast group, indicating that said specific equipment wishes to receive the traffic sent by said included sources;

excluded source lists of a multicast group, indicating that said specific equipment wishes to receive the traffic sent by all the sources of said multicast group except said excluded sources; and

so that said specific records stored in said router separately contain, for each specific equipment and multicast group, the data of said included sources and the data of said excluded sources.

32. A router according to claim 28, characterized in that it stores executable instructions for finding out if it is connected to a switch to which other routers are also connected, and if it does only sending said messages to said switch if it is in one of the two following cases:

said router transmits to the switch the traffic of a multicast channel;

said router receives requests for traffic of a multicast channel sent by a source which is connected to said router through said switch.

33. A switch compatible with the method according to claim 17, characterized in that it stores executable instructions for, when data carrying multicast traffic is received through one of its ports, based on the destination and origin addresses of said data carrying multicast traffic, and based on said identification of the specific equipment and on said specification of the specific multicast traffic which said router has sent to said switch by means of said message, deducing if said data carry said specific traffic which has been requested by said specific equipment, and said switch decides through which of its ports it transmits said data.

34. A switch according to claim 17, characterized in that it stores executable instructions for storing in specific records, for each equipment and multicast group, information about the sources the traffic of which has been requested by said equipment, and updating said records when said switch receives one of said messages sent by said router.

35. A switch according to claim 18, characterized in that it stores executable instructions for storing said specific records such that such records separately contain, for each specific equipment and multicast group, included source lists of a multicast group, indicating that said specific equipment wishes to receive the traffic sent by said included sources, and excluded source lists of a multicast group, indicating that said specific equipment wishes to receive the traffic sent by all the sources of said multicast group except said excluded sources.

36. A switch according to claim 33, characterized in that it stores executable instructions for receiving said messages sent by said router, said messages being layer 3 messages in the OSI (Open Systems Interconnection) model, and for, when said switch receives data through one of its ports, analyzing the destination address of said data for finding out if said data carries one of said messages sent by said router and if it does, not transmitting said data and processing it to read said message.