Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watnot!watmath!clyde!rutgers!ames!ucbcad!ucbvax!CS.UCL.AC.UK!jon From: jon@CS.UCL.AC.UK.UUCP Newsgroups: mod.protocols.tcp-ip Subject: Re: [dae%psuvax1.bitnet@jade.Berkeley.E Message-ID: <8703241224.AA03823@ucbvax.Berkeley.EDU> Date: Tue, 24-Mar-87 05:10:52 EST Article-I.D.: ucbvax.8703241224.AA03823 Posted: Tue Mar 24 05:10:52 1987 Date-Received: Thu, 26-Mar-87 01:15:43 EST Sender: daemon@ucbvax.BERKELEY.EDU Distribution: world Organization: The ARPA Internet Lines: 45 Approved: tcp-ip@sri-nic.arpa /* Written 2:08 pm Mar 23, 1987 by tcp-ip@pyr1 in pyr1:tcp-ip */ /* ---------- "Re: [dae%psuvax1.bitnet@jade.Berkeley.E" ---------- */ Received: from ucl-cs-nss by pyr1.Cs.Ucl.AC.UK with SMTP id aa16134; 23 Mar 87 14:06 WET Received: from sri-nic.arpa by mv1.Cs.Ucl.AC.UK via Satnet with SMTP id aa05875; 23 Mar 87 14:00 WET Received: from vax.darpa.mil by SRI-NIC.ARPA with TCP; Mon 23 Mar 87 04:16:01-PST Posted-Date: Mon 23 Mar 87 07:15:18-EST Received: by vax.darpa.mil (5.54/5.51) id AA01929; Mon, 23 Mar 87 07:15:21 EST Date: Mon 23 Mar 87 07:15:18-EST From: "Dennis G. Perry" Subject: Re: [dae%psuvax1.bitnet@jade.Berkeley.EDU: Network horror story] To: LYNCH@edu.isi.a Cc: PERRY@mil.darpa.vax, TCP-IP@arpa.sri-nic, perry@mil.darpa.vax Message-Id: In-Reply-To: Message from "Dan Lynch " of 22 Mar 1987 19:25:30 EST Dan, not sure there has been any model, or any great research either. dennis ------- /* End of text from pyr1:tcp-ip */ If you look at the original Internet design issues, the idea of fate sharing and a tactical network, and so on, determined gateway/routers were connectionless. A bit like the old CSMA versus token arguments, in a WAN context, the consequence of this design decision is that (without resource reservation a la X.25) you HAVE to over-engineer for bandwidth and delay, or it just doesn't work. Witness the UK Academic X.25 network availability under extreme load is 99% plus, with MTTR in the minutes, and MTBFs in the days range, compared with the Internet under extreme load, where we were seeing availabilities of 20-30% and MTTRs of hours and MTBFs in the hour range. I look forward to seeing some intermediate scheme ("connectionish networks") for the tactical+low-congestion internet. Jon