Method of providing a rendezvous point

A method of providing a rendezvous point (RP) facility in sparse mode protocol independent multicast (PIM) communications over a data communication network, the method comprising:

• selecting as designated router (DR) a particular router on a sub-network which includes a plurality of routers with respective individual IP addresses, so that the DR performs RP processing during PIM multicasting, an additional active IP address of the DR being a specified RP address to which multicast data is sent for RP processing;
• and
• designating another router on the sub-network as new DR in response to occurrence of a predetermined failure event associated with the DR, designation of the new DR being by activating the RP address on the new DR in addition to the new DR's individual IP address, so that the new DR performs RP processing after its designation.

A method of designating a particular router in a data communications sub-network as designated router (DR) for performing rendezvous point (RP) processing during protocol independent multicast (PIM) communication, the method comprising:

• assigning to each of a plurality of routers on the sub-network identical IP addresses in addition to each router's individual IP address, the additional IP addresses being identical to an RP address;
• and
• deactivating the additional address of each router except the DR, so that the RP address of only the DR is active.

A machine readable-medium embodying instructions to provide a rendezvous point (RP) facility in sparse mode protocol independent multicast (PIM) communications over a data communication network, the instructions when executed by a machine cause the machine to:

• select as designated router (DR) a particular router on a sub-network which comprises a plurality of routers with respective individual IP addresses, so that the DR performs RP processing during PIM multicasting, an additional active IP address of the DR being a specified RP address to which multicast data is sent for RP processing;
• and
• designate another router on the sub-network as new DR in response to occurrence of a predetermined failure event associated with the DR, designation of the new DR being by activating the RP address on the new DR in addition to the new DR's individual IP address, so that the new DR performs RP processing after its designation.

A system to provide a rendezvous point (RP) facility in sparse mode protocol independent multicast (PIM) communications over a data communication network, the system comprising:

• means for selecting as designated router (DR) a particular router on a sub-network which includes a plurality of routers with respective individual IP addresses, so that the DR performs RP processing during PIM multicasting, an additional active IP address of the DR being a specified RP address to which multicast data is sent for RP processing;
• and
• means for designating another router on the sub-network as new DR in response to occurrence of a predetermined failure event associated with the DR, designation of the new DR being by activating the RP address on the new DR in addition to the new DR's individual IP address, so that the new DR performs RP processing after its designation.