| Major Improvements in TCP Performance over Satellite and Radio
Dr. Lawrence G. Roberts
4/1/06
Research sponsored by DARPA
TCP performance deteriorates rapidly with packet loss and delay. The response to packet loss is inherent in TCP’s design so as relieve congestion in the network but if the packet loss is due to channel noise it is an incorrect response. Also, the reduced throughput due to satellite delays is an unfortunate side effect of the TCP process. If one can determine the highest rate that does not cause congestion, then TCP could be sent without any substantial throughput degradation. This paper introduces a new signaling message, exchanged as a flow is setup, which allows the network to specify the highest rate it can support for the flow, thereby allowing TCP to proceed immediately (skipping slow-start) at this rate. Since the network will tell the source if it needs to slow down with a message, there is no need for packet discards and any lost packet can be considered to be caused by noise and thus retransmitted without slowing down. This protocol has been standardized by the Telecommunications Industry Association as TIA 1039 and is specified to operate with both IPv4 and IPv6 (with encryption). The paper describes the operation and shows the major improvements possible.
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| Dr. Lawrence G. Roberts
CEO & President, Anagran Inc.
lroberts@anagran.com
Dr. Roberts has had a long career in telecommunications management, both in service as a carrier and in manufacturing as a vendor. He received his BS, MS, and PhD from MIT. His networking career started at MIT when he networked the first two computers. When this proved successful, he was recruited into APRA to manage the computer and communication research program. At ARPA he designed and managed the development of the first packet network, the ARPANET, now the Internet. When this proved successful, he founded Telenet, the first packet carrier in the world, now part of Sprint. He then founded NetExpress and later ATM Systems, both switching equipment companies. Then in 1999 he founded Caspian Networks to manufacture a new concept in routing, flow routers. In 2004, he founded Anagran where he is CEO, President and Chairman. Anagran is building an advanced Flow Aware Router that will allow voice, video and data to all be combined in IP with the quality of ATM.
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