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From: ewv@craycos.com (Eric Varsanyi)
Newsgroups: comp.unix.i386,comp.dcom.sys.cisco
Subject: Re: ISC 2.2 SL/IP throughput?
Message-ID: <1990Aug29.233628.2595@craycos.com>
Date: 29 Aug 90 23:36:28 GMT
References: <3694@wb3ffv.ampr.org> <26@astph.UUCP> <1990Aug23.160013.1199@scuzzy.mbx.sub.org>
Organization: Cray Computer Corporation
Lines: 41

In article <1990Aug23.160013.1199@scuzzy.mbx.sub.org> src@scuzzy.mbx.sub.org (Heiko Blume) writes:
>can someone tell me what throughput i can expect with sl/ip over
>a modem connection with HST modems (14400bps)?

This does not directly relate to HST's, but it might be interesting anyway.

Configuration:
--------------
	SCO Unix (3.2.2) with the vanilla driver on a vanilla serial board
	Connection between 2 Telebit T2500's.
	Cisco terminal server providing slip bridge onto ethernet 
	Transfer of 100 Kb file (binary, Unix kernel from a Sparc)
	19200 hardware flow control on both sides

Numbers:
--------
		Kb/s (reported by ftp)	Roundtrip (reported by ping)
V.32 mode	.795			370
(s50=6)

Pep		.799			1420

Pep/compressed	.823			1551	
(s110=1)

Watching the lights on the modem it looked like Pep's reverse channel was
not wide enough to avoid turning the line around every few packets to
send back the ACK's.

Interactive was virtually useless at 1.4 seconds/echo, but using V.32
even editing with vi is tolerable. Compressed mode isn't worth the trouble
unless you are sending BIG files.

Does anyone know when/if Telebit is going to put IP header prediction into
the modems (so they don't have to turn around for the ACK's)?

-Eric Varsanyi
 Cray Computer Corporation
 ewv@craycos.com
-- 
-Eric Varsanyi (ewv@craycos.com)        Cray Computer Corporation