jon@CS.UCL.AC.UK.UUCP (03/24/87)
/* 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" <PERRY@mil.darpa.vax>
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: <VAX-MM(195)+TOPSLIB(124) 23-Mar-87 07:15:18.VAX.DARPA.MIL>
In-Reply-To: Message from "Dan Lynch <LYNCH@A.ISI.EDU>" 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