> From: Bob Braden <bra...@isi.edu> > You probably remember this, but...
I was on the very edge at the time (more below), but yes. A few things that caught my eye (including a minor date offset - I like to get noise out of the record before it gets engrained): > argued strenuously for variable length addresses. (This must have > been around 1979. I cannot name most of the other 10 people in the > room, but I have a clear mental picture of Jon, in the back of the > room, fuming over this issue. Jon believed intensely in protocol > extensibility.) There was a discussion about this on the internet-history list (although in the content of TCP/IP-v4's birthday) back at the end of March, 2006: http://mailman.postel.org/pipermail/internet-history/2006-March/date.html It turned out that the relevant meeting was the one held at MIT on 15-16 June 1978 (minutes are in IEN-68); the final formats for TCP4 and IPv4 were picked on 16 June, and documented in IEN-44 ("Latest Header Formats") immediately thereafter. I don't know about Jon or Danny, but I have a _very_ clear memory of David Reed coming out of the meeting and being totally disgusted! (My office was just a few feet down the hall from the conference room - I wasn't in the meeting, I guess I wasn't considered 'real' enough yet! My first meeting was the August, 1978 meeting.) > His argument was that TCP/IP had to be simple to implement if it > were to succeed > ... > variable length addresses seemed to be (and in fact would be) harder > to program and would make packet dumps harder to interpret. The sad part is that we could have had our cake, and eaten it too! If we'd kept the variable length packet format, and said 'for now, the only supported length is 4', we'd have had the best of both worlds: simple implementations, and longer-term flexibility. (I have no problems with implementation hacks: e.g. the early MIT router code for subnets initially had a 'MyANet' static variable in it, which was non-0 on a subnetted network! :-) It would have been so _easy_, if only we'd thought of it! And look how much it would have saved us!! Oh well, 20/20 hindsight. But this need to have a perfect balance between implementability and long-term flexibility is a lesson that has stayed with me very forcefully. > (and survive the juggernaut of the ISO OSI protocol suite). I don't really recall the ISO suite being a big concern at that point? I know some years later it was, but it was totally off my personal radar at that point. I do recall very clearly some mutterings in the hallway after the June 78 meeting about the number of pointer registers available at interrupt time in TENEX (although to be fair I doubt that was the reason fixed-length was chosen)! Noel _______________________________________________ Ietf mailing list Ietf@ietf.org https://www.ietf.org/mailman/listinfo/ietf