Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!uflorida!gatech!emory!km
From: km@emory.uucp (Ken Mandelberg)
Newsgroups: comp.dcom.modems
Subject: Kermit with Trailblazer
Message-ID: <3452@emory.uucp>
Date: 28 Nov 88 03:58:22 GMT
Organization: Math & Computer Science, Emory University, Atlanta
Lines: 39

The built in Kermit protocol support on the Trailblazer seems not to be
as useful as I had hoped. Here are the results of some Kermit file
transfers I did with a 23K test file. Both systems were hooked to
Trailblazer+'s at 9600 baud.

Packet Size   Kermit Spoofing  Time for Transfer
  90               ON            105 secs
  90               OFF           385 secs
 256               OFF           169 secs
 512               OFF           106 secs
1000               OFF            73 secs

This is all with C-kermit 4E(070). When I tried packets above 1000
bytes the transfer timed out, and I didn't want to trouble shoot it. On
one side the computer (a 3B1) is directly connected to the Trailblazer.
On the other side the computer (a Sun) was connected through a terminal
server. The long packet timeouts could have been trouble in any of
kermit/modems/terminal server or the two computers. However, note that
maximum transfer rate (with 1000 byte packets) is 315 chars/sec, and
the same hardware gives about 900 chars/sec with UUCP (spoofing on).

One interesting thing is that although the Trailblazer does benefit
from the spoofing at small packet sizes, at anything above 512 byte
packets I am better off just doing without spoofing and eating the line
turnaround time.

Unless there is something unusual about my experiment it would appear
that you are better off without the Trailblazers Kermit support unless
you are forced to communicate with a system (or through a communication
link) that forces small packets.

Is it time to try and get the Telebit people to allow the Kermit
spoofing to use more than 90 character packets?

-- 
Ken Mandelberg      | km@mathcs.emory.edu          PREFERRED
Emory University    | {decvax,gatech}!emory!km     UUCP 
Dept of Math and CS | km@emory                     NON-DOMAIN BITNET  
Atlanta, GA 30322   | Phone: (404) 727-7963