Other changes proposed to TCP

• Mark Allman, On the Generation and Use of TCP Acknowledgments, ACM CCR, October 1998.
  This paper compares acking-every-packet and delayed-ack mechanisms with three alternate mechanisms: acking-every-packet only during slow-start; unlimited byte-counting; and limited byte-counting. With unlimited byte-counting, the sender increases its congestion window based on the number of bytes covered by each ack. With limited byte-counting, the increase of the congestion window for each ack is limited to two segments.

• Mohit Aron and Peter Druschel, TCP: Improving Start-up Dynamics by Adaptive Timers and Congestion Control, TR98-318, Rice University, 1998.
  This paper proposes the use of packet pacing in the initial slow-start, and proposes a method for conservatively estimating the initial ssthresh. This paper also proposes decoupling the clock granularity used for measuring the roundtrip time from that used for scheduling events, allowing for shorter retransmission timeouts.

• Hari Balakrishnan and Randy H. Katz, Explicit Loss Notification and Wireless Web Performance, IEEE Globecom Internet Mini-Conference, Nov. 1998 (to appear).
  This paper proposes Explicit Loss Notification to improve performance when a mobile host is the TCP sender.

• Hari Balakrishnan, Venkata Padmanabhan, and Randy H. Katz, The Effects of Asymmetry on TCP Performance ( postscript, gzipped postscript), Third ACM/IEEE Mobicom Conference, Budapest, Hungary, Sep 1997.
  This paper proposes techniques for decreasing the frequency of ACKs on the constrained reverse channel ("ACK congestion control" and "ACK filtering"), techniques to reduce source burstiness when ACKs are infrequent ("sender adaptation via traffic shaping" and "ACK reconstruction"), and algorithms for scheduling data and ACKs at the reverse bottleneck router.

• Reuven Cohen and Srinivas Ramanathan, TCP for High Performance in Hybrid Fiber Coaxial Broad-Band Access Networks, IEEE/ACM Transactions on Networking, Vol. 6, No. 1, February 1998.
  This paper proposes proper sizing of TCP socket buffers, an initial window of two packets (as opposed to one packet), smaller MSS values to counterack problems with delayed ACKs and ACK losses, a finer granularity for TCP timers, and Fast Retransmit triggered by a single dup ACK.

• T. Faber, J. Touch and W. Yue, Avoiding the TCP TIME_WAIT state at Busy Servers, Working Draft, September 1997.
  This internet draft describes two methods for avoiding the accumulation of TCP TIME_WAIT states at a network server, including a TCP modification that causes clients rather than servers to enter TIME_WAIT state.

• Sally Floyd and Thomas Henderson, The NewReno Modification to TCP's Fast Recovery Algorithm, Working Draft, February 1999 (local copy).
  This internet draft describes a specific algorithm for responding to partial acknowledgments, referred to as NewReno. This response to partial acknowledgments was first proposed by Janey Hoe in [Hoe95].

• Thomas Henderson and Randy Katz, Transport Protocols for Internet-Compatible Satellite Networks, (to appear), IEEE Journal on Selected Areas in Communications, 1999.
  This paper compares the performance of various TCP implementations in a satellite environment, and discusses the use of a satellite gateway, proxy, or web cache to "split" transport connections in a manner transparent to users. The paper proposes a new transport protocol, Satellite Transport Protocol (STP), optimized for the asymmetric bandwidth and high latency of satellite environments.

• J. Touch, TCP Control Block Interdependence, RFC 2140, April 1997.
  This informational RFC proposes interdependent TCP control blocks for sharing TCP state among concurrent connections or across similar connection instances.

• Vikram Visweswaraiah and John Heidemann, Improving Restart of Idle TCP Connections, Technical Report 97-661, University of Southern California, November, 1997.
  This paper proposes pacing packets during a restart of an idle TCP connection until the "ACK clock" can be restarted.

• Venkata Padmanabhan, TCP Fast Start: A Technique For Speeding Up Web Transfers, Global Internet '98 Conference, November 1998.
  This paper proposes that the sender caches network parameters, and uses higher drop priority for packets sent during Fast Start.

The Commercial World: Selected Pointers

• TCP Rate Control, Packeteer. This applies rate-based flow control policies to both individual traffic flows and classes of flows.

TCP and DiffServ

Other pointers

• TCP/IP RESEARCH PAPERS. Mark Allman's pointers to a vast collection of papers on TCP.

• IETF's TCP Over Satellite Working Group.

• TCPng BOF (postscript of viewgraphs, minutes), San Jose IETF, December 1994.

• Publications from U.C. Berkeley's Daedalus Project. This includes pointers to papers by Hari Balakrishnan, Tom Henderson, Randy Katz, Venkat Padmanabhan, and others about TCP and other issues.

• LSAM (Large-Scale Active Middleware) Publications. This includes pointers to papers by John Heidemann, Joe Touch, and others about TCP and web performance.

Return to [Sally Floyd].