Path: utzoo!attcan!uunet!mitel!sce!scs!spl1!gargoyle!tank!uwvax!rutgers!tut.cis.ohio-state.edu!ucbvax!decwrl!sgi!vjs@rhyolite.wpd.sgi.com
From: vjs@rhyolite.wpd.sgi.com (Vernon Schryver)
Newsgroups: comp.dcom.modems
Subject: Re: Are Trailblazers good for SLIP 9600 Baud? What then?
Message-ID: <37412@sgi.SGI.COM>
Date: 3 Jul 89 21:24:01 GMT
References: <219@csis.oz> <2109@unisoft.UUCP>
Sender: daemon@sgi.SGI.COM
Organization: Silicon Graphics, Inc., Mountain View, CA
Lines: 24

In article <2109@unisoft.UUCP>, cander@unisoft.UUCP (Charles Anderson) writes:
> 
> ...I found that SLIP between two
> serial ports without modems ran at roughly 75% of the maximum
> throughput (9600 baud) and that with the TB's in the loop performance
> was roughly 50% of 9600 baud...
> 
> Charles.
> {sun, amdahl, ucbvax, pyramid, uunet}!unisoft!cander


I've noticed similarly low numbers for rcp of .5KB/sec between IRIS's over
interfaces set to 19.2, but with FTP, I've seen 1.4KByte/sec on the same
phone calls.  Notice that 1.4KB is about what you can hope for with UUCP
over TB's.  No TCP retransmissions were glaringly obvious.  TB compression
does not seem to make much difference.  The modem lights look about the
same in all cases--almost solid one-way traffic.  Given the large buffers
of rcp and the large TCP windows on IRIS's, I don't know what's going on.
Does anyone else?


Vernon Schryver
Silicon Graphics
vjs@sgi.com