From: peter honeyman <honey@citi.umich.edu>
Date: Fri, 13 Aug 93 05:58:25 PDT
To: cypherpunks@toad.com
Subject: Re: Secure voice software issues
Message-ID: <9308131255.AA23722@toad.com>
MIME-Version: 1.0
Content-Type: text/plain


> do not use error correction or compression.  (they will slow you down)

huh?!?  my file transfer times would *double* if i turned off v.42bis
(modem compression).  *that* would slow me down.  and you can't run
v.42bis without running the error handling protocol (v.42), for obvious
reasons.  what's more, v.42 gives an immediate 20% (or so) increase in
throughput, by eliminating start and stop bits.

arguably, i could (and should) be running compression in my slip or ppp
driver, but certainly it is false to say that v.42bis and v.42 slow me
down -- the opposite is true.

> and tcp does it's own error correction.  as for 160ms round trip times
> that is acceptable for slip.

i don't much care about round-trip times, as i use my slip line principally
for afs, which runs as a data stream.  round-trip delays are amortized over
file transfers.

phil karn's points about modem buffering interfering with type-of-service
queueing are the strongest condemnations of modern modems, in my view.
i wish someone would build a modem that recognized ip packet framing.

	peter