Path: utzoo!attcan!uunet!snorkelwacker!usc!ucsd!brian
From: brian@ucsd.Edu (Brian Kantor)
Newsgroups: comp.sys.att,u3b.tech,u3b.misc
Subject: Re: 3B2/310 & TB+
Keywords: Hardware Flow
Message-ID: <16192@ucsd.Edu>
Date: 25 Jul 90 15:33:19 GMT
References: <3580@sactoh0.UUCP> <1990Jul25.062920.12777@robohack.UUCP>
Followup-To: comp.sys.att
Organization: The Avant-Garde of the Now, Ltd.
Lines: 18

My experience with the 3B2/310 is that it can't handle 19200 bps
sustained flow such as it would get using a trailblazer in uucp spoof
mode.  It drops characters and thus uucp does lots and lots of retries.
Dropping down to 9600 bps actually increased uucp performance in my
tests.

This is particularly true of the console and contty ports, and is true
of the ports board as well, but to a lesser extent.

Note that the retries are between the 3B2 and the modem - the other end
of the connection will never see them, since the modem is spoofing the
protocol.  You need to run the 3B2 in debug to even see it happening,
and you might not be able to get an idea of the delays involved unless
you stick a serial-line data monitor between the port and the modem.

I believe the E-ports board in the large 3B2s can handle 19200 better
than that, but I've never gotten around to trying it on our 3B2/1000s.
	- Brian