MQCC: Maximum Queue Congestion Control for Multipath Networks with Blockage

This paper presents a transport layer protocol for multi-path networks with blockage. Using urban SATCOM as an example, we see from data taken from a 2006 measurement campaign that these blockages are generally on the order of 1 -- 5seconds in length and the links are blocked approximately 33%of the time. To compensate for this type of impairment, we have developed a multipath IP overlay routing algorithm, a random linear coding reliability scheme, and a maximum-queue-based (MQCC) congestion control algorithm. MQCC uses average buffer occupancy as a measure of the congestion in a network (as opposed to packet loss or round trip time (RTT)) and updates the transmission rate of each source to avoid network congestion. This allows us to design a congestion control algorithm that is independent of the channel conditions and can be made resilient to channel losses. The reliability scheme uses selective negative acknowledgments (Snacks) to guarantee packet delivery to the destination. We show through simulation that we can approach the optimal benchmark in realistic loss blockage channels.