Patent ID: 8612617

Claim:
A method for use in a computer system, the method comprising: negotiating with a plurality of client devices, via a join channel, to join and exit a multicast transmission session at different times, wherein a first one of the plurality of client devices is permitted to join the multicast transmission session at a first time and wherein a second one of the plurality of client devices is permitted to join the multicast transmission session at a second time, wherein the first time is different from the second time, and wherein each of the plurality of client devices is able to receive the entirety of content associated with the multicast transmission session regardless of when each of the plurality of client devices joins the multicast transmission session; communicating with the plurality of client devices, via a query channel, about a status of the multicast transmission session; via a polling channel: (i) transmitting polling queries received from a content transfer protocol, (ii) receiving, from the plurality of client device, responses to the polling queries, and (iii) passing the responses to the content transfer protocol; transmitting data to the plurality of client devices via a data channel; querying the plurality of client devices to determine a round trip time associated with each of the plurality of client devices; selecting a single representative client device from the plurality of client devices to be a sender of acknowledgement messages based upon the determined round trip times; and advertising a minimum negative acknowledgement back-off interval based on the round trip time associated with the selected representative client device.