*BSD News Article 73820


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From: iialan@iifeak.swan.ac.uk (Alan Cox)
Newsgroups: comp.os.linux.networking,comp.unix.bsd.netbsd.misc,comp.unix.bsd.freebsd.misc
Subject: Re: TCP latency
Date: 15 Jul 1996 18:33:53 GMT
Organization: Institute For Industrial Information Technology
Lines: 25
Message-ID: <4se2uh$7el@news.swan.ac.uk>
References: <Pine.LNX.3.91.960709020017.19115I-100000@reflections.mindspring.com> <x74tnfn35s.fsf@oberon.di.fc.ul.pt> <4s33mj$fv2@innocence.interface-business.de>
NNTP-Posting-Host: iifeak.swan.ac.uk
Xref: euryale.cc.adfa.oz.au comp.os.linux.networking:45306 comp.unix.bsd.netbsd.misc:4058 comp.unix.bsd.freebsd.misc:23648

In article <4s33mj$fv2@innocence.interface-business.de> joerg_wunsch@interface-business.de (Joerg Wunsch) writes:
>I do know that the BSD TCP code sometimes suffers from poor recovery
>behaviour on lossy lines (packet loss >~ 50 %, as it can often be
>observed on transatlantic or transpacific links).  Is this what you
>mean?

Thats not really something I'd point at BSD and say "BSD fault", thats a
fundamental limitation of the crude error correction scheme used by
TCP (acks).

>Anyway, i'm afraid a pageable routing table might cause a lousy
>network performance in case of memory tightness.

A pageable routing table is unworkable. The only case people have user
space routing tables is for multicast where it kind of comes out ok in the
wash and the alternative isnt palatable. Thats how mrouted works.

Alan


-- 
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Yow! 233 microsecond remote host TCP latency ---- beat that
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Alan Cox, Alan.Cox@linux.org               /_____________/ / /\/ /_/ ><