IGMP expedited leave triggered by MAC address

• US 20040117503A1
• Filed: 12/12/2002
• Published: 06/17/2004
• Est. Priority Date: 12/12/2002
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: Alcatel Canada Inc. (Nokia Corporation)
• Inventors: Aboukarr, Bakri, Gyetko, Gregory Erich, Nguyen, Dat Ba
• Granted Patent: US 7,228,356 B2
• Time in Patent Office: Days
• US Class Current: 709/238
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• CPC Class Codes: H04L 47/15 in relation to multipoint traffic arrangements for broadcast or multicast in data networks H04L12/18
• CPC Class Codes: H04L 47/70 Admission control; Resource allocation
• CPC Class Codes: H04L 47/806 Broadcast or multicast traffic

Abstract

Method and apparatus for improving channel changing or channel surfing functionality in IGMP supported services.

Claims

1. A method of managing IP multicast connections in a communications network having one or more network nodes connected to a plurality of end-user devices, comprising the steps of:

(a) receiving, at a network node in the network, an IGMP Group Join message from an end-user device serviced by said network;

(b) comparing, at said network node, a MAC address, obtained from the Join message, of said end-user device to another MAC address obtained from a pending Leave message for which there exists an IP multicast connection to said network node;

(c) determining, at said network node, whether or not any other end-user device is listening to the multicast group of the pending Leave message; and

(d) initiating, responsive to no other end-user device listening to the multicast group and responsive to a match resulting from the comparison, an Expedited Group Leave action for said end-user device on the IP multicast connection.

2. The method defined in claim 1 further characterized by the step of sending a GSQ message to all end-user devices serviced by the network node, and further comprises re-connecting the end-user device responsive to said network node receiving an affirmative response of the GSQ message from said end-user device.

3. In an IP multicast communications network employing IGMP signaling protocol and having a network node means, a plurality of end user devices connected to said network node means, a means in said network node for receiving a Group Join message, which includes a MAC address, from an end user device serviced by said network, the improvement in the method of managing IP multicast connections in said communication network characterized by:

determining at said node whether any STB is listening to a particular multicast group by;

keeping a memory table of the MAC addresses of the listening STBs when Join messages are received for each multicast group, and whenever a new Join message is received, determines whether bandwidth usage of the pending Leave(s) can be released by checking said memory table to determine whether an Expedited Leave action can be performed on a pending Leave according to the following;

(a) if the multicast group table contains any MAC address(es) other than the one belonging to the pending Leave message, then the Expedited Leave action cannot be performed, and

(b) if the multicast group table contains only the MAC address which matches the MAC address of the pending Leave then the Expedited Leave action can be executed.

4. In an IP multicast communications network employing IGMP signaling protocol and having video-on-demand head end coupled to one or more network nodes, a plurality of end-user devices, means in said network node for receiving a Group Join message from an end-user device serviced by said network, the improvement comprising:

said network node having means for performing the following functions;

comparing an MAC address extracted from said Group Join message with MAC addresses of pending Leave messages, determining whether or not any other end-user is listening to the multicast group of the pending Leave message, and in the absence of any other end-user device listening to the multicast group and responsive to a match resulting from said comparison, initiating an expedite a Group Leave action with the end-user device on the IP multicast connection.

5. The invention defined in claim 4 wherein said network node includes at least one DSLAM.

6. The invention defined in claim 4 wherein said end-user device includes a set-top box.

7. In an IP multicast communications network employing IGMP signaling protocol and having network node means, a plurality of end-user devices connected to said network node means, and means in said network node for receiving a Group Join message, which includes a MAC address, from an end-user device serviced by said network, the improvement comprising:

said network node including means for performing the following functions;

comparing MAC addresses extracted from said Join message, with the MAC addresses associated with pending Join and Leave messages, determining whether or not any other end-user is listening to the multicast group of the pending Leave message, and (a) in the absence of any other end-user device listening to the multicast group and (b) responsive to a match resulting from said comparison, initiating an expedited Group Leave action with the end-user device on the IP multicast connection.