Path: utzoo!utgpu!water!watmath!clyde!rutgers!ames!amdcad!sun!pitstop!sundc!seismo!uunet!munnari!basser!john
From: john@basser.oz (John Mackin)
Newsgroups: comp.dcom.modems,aus.acsnet
Subject: Re: Trailblazers on full-duplex protocols
Summary: not for Sun III, they don't...
Message-ID: <1187@basser.oz>
Date: 9 Feb 88 20:18:16 GMT
References: <231@stcns3.stc.oz>
Reply-To: john@basser.oz (John Mackin)
Organization: Dept of Comp Sci, Uni of Sydney, Australia
Lines: 36

In article <231@stcns3.stc.oz> dave@stcns3.stc.oz (Dave Horsfall) writes:

> I am wondering how [the Trailblazer] performs on real full-duplex protocols.
> Methinks it would lose quite a bit of its claimed throughput...

It does.  We tried a pair between here and the University of Queensland
last year.  The best we could get was about 100 characters/sec (as shown
by linkstats -V), i.e. far short of normal 1200 baud modems.  [I say
_far_ short, just so there's no confusion, because these are full duplex
protocols we're talking about, not half duplex -- with V.22 modems on a
normal telephone connection, we get data rates in the region of 220-230
characters/sec, assuming there is data to be transferred both ways.]
They're no use if they don't understand your protocol.  Now, for
interactive use, if you could afford them they'd be wonderful -- the
echo delay was noticeable but not massively annoying, and the speed was
terrific! 

> No - I'm not knocking the 'Blazer.  I'm just concerned that should
> my company go out and buy a couple, it won't perform anywhere near
> as well as suggested, because we talk a different language!

Absolutely right.  Piers made vague noises at the time about doing
a protocol module for them, but unless and until that happens,
they're no good for Sun III.  (Or Sun IV for that matter.)

> Saw several ads in the local computer gutter press here, about the
> "NetComm (The Australian Company) Trailblazer".  [...] Wonder if it's
> no more than a foreign import, with a local line interface?

That's way we tried, and yes, that's what it is.

John Mackin, Basser Department of Computer Science,
	     University of Sydney, Sydney, Australia

john@basser.oz.AU (john%basser.oz.AU@UUNET.UU.NET)
{uunet,hplabs,mcvax,ukc,nttlab}!munnari!basser.oz!john