Abstract

won't go through the details, but Figure 2 shows the pathological behavior that can result from multiple Fast Retransmits in one roundtrip time. This work was supported by the Director, Office of Energy Research, Scientific Computing Staff, of the U.S. Department of Energy under Contract No. DE-AC03-76SF00098. This problem is somewhat more difficult to duplicate in simulations with Reno implementations. With Reno implementations, the source essentially assumes that only one packet has been dropped, retransmits that dropped packet, and instead of waiting for the ACK to be received, continues transmitted new packets. For multiple packet drops in one roundtrip time, the Reno source often has to wait for a retransmit timer to recover (given the absence of Selective ACKs). And in some circumstances with Reno, the ability to have multiple Fast Retransmits in a single roundtrip time can avoid the wait for a retransmit timer timeout, in the absence of Selective ACKs.

Citations