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From: jdeitch@jadpc.cts.com (Jim Deitch)
Newsgroups: comp.mail.uucp,comp.dcom.modems
Subject: Re: What should a new UUCP protocol do?
Message-ID: <1990Nov09.050218.2485@jadpc.cts.com>
Date: 9 Nov 90 05:02:18 GMT
References: <1990Nov07.155516.17815@ism.isc.com>
Distribution: usa
Organization: Network Engineering Technologies
Lines: 53

In article <1990Nov07.155516.17815@ism.isc.com> johnan@ism.isc.com (John Antypas) writes:
>Interactive Systems is now the fortunate owner of many different modems.
>Some are Telebits, some are V.32, some are 2400 baud no-namers, etc.
>Unfortunately, we do UUCP with all of them.  We've been looking at the
>transfer stats and have noticed the different flavors of modems each
>treat UUCP a bit different.
>
>We are looking into placing a new protocol into UUCP which copes with
>the higher-speed modems, but doesn't require protocol spoofing, nor
>does it assume your running X.25 (no f protocol).  What characteristics
>should we shoot for when dealing with what we call, the new low-end
>high speed modem.
>
>This "modem" appears to have the followig basics:
>
>NOT V.32, V.42/42.bis, PEP!  Totally unique protocols
>Can do 9600 baud without compression, but with compression can do 38.4K
>Either does not have a back channel, or must "turn the channel around" and 
>   can take a second or so to do it.
>
>I've been looking at a modified 'g' protocol using 2K blocks window size 7.
>Am I completely off track?  Obviously, this works best with ASCII files
>in bulk like Batch SMTP.
>
>Tell us what you want, maybe we can put it in.
>
>John Antypas / Interactive Systems Corp.
>uucp: ...!uunet!ism!johnan    Internet: johnan@ism.isc.com
>All statements above responsability of the author.

How about something that has been in use on the FIDO net system for
quite some time.

When you use the frontend, Binkleyterm, one of the transfer protocols
is called Zed Zap.  What happens is this:  If the connection is 9600
or greater the block size is put at 8k and they use a zmodem type of
streaming protocol.  If the speed is 2400 baud but less than 9600 baud
the block size is 2k and the streaming protocol is used.  If the modem
speed is less than 2400 baud then they use a block size of 1k and the
streaming protocol is used.  This results in the best of both worlds,
high block rates with no reverse channel unless there is a problem.
It also causes an expect error message that is realitivley the same
time wise regardles of the speed of the connection.

You asked and I answered.

Jim

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