Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!apple!sun-barr!decwrl!sgi!vjs@rhyolite.wpd.sgi.com
From: vjs@rhyolite.wpd.sgi.com (Vernon Schryver)
Newsgroups: comp.dcom.modems
Subject: Re: SLIP compression...
Summary: modem no help here
Message-ID: <37639@sgi.SGI.COM>
Date: 9 Jul 89 19:07:08 GMT
References: <340@larouch.UUCP> <5108@oregon.uoregon.edu>
Sender: daemon@sgi.SGI.COM
Organization: Silicon Graphics, Inc., Mountain View, CA
Lines: 16

In article <5108@oregon.uoregon.edu>, jqj@oregon.uoregon.edu (JQ Johnson) writes:
> One possible place to put compression is in the modem itself...[use Telebit's
> normal compression]

After hacking a form of TCP compression into SLIP, which does nothing for
stuff like ICMP, I decided to see what the compression built into a TB+
would do for ping.   The packets sent by ping contain almost no
"information."  The default 56 bytes generated by the 4.3BSD ping is a
simple count.  The IP & ICMP headers do not change very much.  Naively, I
thought a TB+ might compress such a slow, repeative byte stream into
something which would fit into "micro packets."  I had no such luck.
Why?  Has anyone had better luck?

Vernon Schryver
Silicon Graphics
vjs@sgi.com