[e2e] What if there were no well known numbers?

Noel Chiappa jnc at mercury.lcs.mit.edu
Fri Aug 4 13:08:56 PDT 2006

    > From: Bob Braden <braden at ISI.EDU>

    > At 10:39 PM 8/2/2006 -0400, David P. Reed wrote:

    >> The concept of "well-known ports" was built for a world in which there
    >> was no lookup function, no DNS - in fact for a world where people
    >> typed addresses in octal, long before there was a naming service (even
    >> before the hosts file).

    > Well, not exactly. It was (deliberately) built for a world in which we
    > did not want increased communication fragility resulting from DNS
    > lookup failures.

Does it have to be one (no infrastructure) or the other (fragility)? I always
thought it was some of both.

In any event, I got the impression that TCP pretty much just followed NCP's
lead on this. Is there anyone here who was around for the NCP design who can
comment on what NCP's reasons were for well-known ports? My guess would be
lack of infrastructure (as DPR points out, that was before there was even


More information about the end2end-interest mailing list