TCP Implementation (tcpimpl)

Status: Concluded October, 2000 
 Mark Allman 
 Vern Paxson 
Description of Working Group:
The objective of this group is to decide how to best address known
problems in existing implementations of the current TCP standard(s) and
practices.  The overall goal is to improve conditions in the existing
Internet by enhancing the quality of current TCP/IP implementations. It
is hoped that both performance and correctness issues can be resolved
by making implementors aware of the problems and their solutions.  In
the long term, it is felt that this will provide a reduction in
unnecessary traffic on the network, the rate of connection failures due
to protocol errors, and load on network servers due to time spent
processing both unsuccessful connections and retransmitted data.  This
will help to ensure the stability of the global Internet.
Examples of detected problems:
o TCPs that retransmit all unacknowledged data at a single time.
  This behavior greatly adds to Internet load, at a time when
  the network is already under stress.  The combination can
  lead to congestion collapse.
o TCPs that misinitialize the congestion window, leading to
  potentially enormous bursts of traffic when new connections
  begin.  Such burstiness can greatly stress Internet routers.
In the BOF, it was generally agreed that problems of this class need
to be fixed.
The scope of this group must be carefully defined in order to ensure
timely progress. To this end, TCP issues that still remain areas of
research are  considered out of scope for the WG.  For example new
improvements in congestion control algorithms are not within the WG
scope. The WG will solicit input from the End-To-End research group of
the IRTF on questions of whether a TCP implementation issue is
considered research.
The major objectives of this group will be to :
Produce a compilation of known problems and their solutions.  This will
raise awareness of these issues.
Determine if any problems found are the result of ambiguities in the
TCP specification.  If necessary, produce a document which clarifies
the specification.
Catalog existing TCP test suites, diagnostic tools, testing
organizations, and procedures that can be used by implementors to
improve their code, and produce a document enumerating them.

Request for Comments:

  • RFC2398 Some Testing Tools for TCP Implementors (Informational)
  • RFC2414 Increasing TCP's Initial Window (Experimental)
  • RFC2415 Simulation Studies of Increased Initial TCP Window Size (Informational)
  • RFC2416 When TCP Starts Up With Four Packets Into Only Three Buffers (Informational)
  • RFC2525 Known TCP Implementation Problems (Informational)
  • RFC2581 TCP Congestion Control (Proposed Standard)
  • RFC2582 The NewReno Modification to TCP's Fast Recovery Algorithm (Experimental)
  • RFC2923 TCP Problems with Path MTU Discovery (Informational)