Patent ID: 6182147
Filing Date: 2001-01-30
Classification: H04L

Abstract:
A method, comprising the following steps:transmitting multicast messages from a set of sending devices to a set of uplink routers;transmitting said multicast messages from said set of uplink routers to a set of downlink routers, using a substantially unidirectional communication path;transmitting said multicast messages from said set of downlink routers to a set of destination devices; andaltering distribution of said multicast messages from said set of sending devices to said set of destination devices using a multicast group management protocol, said steps for altering including communicating protocol messages from said set of downlink routers to said set of uplink routers using a reverse communication path, said reverse communication path having substantially less bandwidth than said substantially unidirectional communication path, wherein one of said downlink routers acts as a proxy for said set of downlink routers, the altering of the distribution of the multicast messages also involving changing a membership status of at least one destination device in the set of destination devices, the membership status being with regard to membership in at least one of a plurality of multicast message destination groups, the changing of the membership status being initiated by transmission by the one destination device to one downlink router associated with the one destination device of a request to change the membership status, the one downlink router reporting the request to one uplink router associated with the group, unless at least one predetermined condition exists, via the reverse communication path.