Path: utzoo!utgpu!watserv1!watmath!att!pacbell.com!ucsd!usc!zaphod.mps.ohio-state.edu!swrinde!cs.utexas.edu!yale!spock!lancelot
From: lancelot@spock.UUCP (Thor Lancelot Simon)
Newsgroups: comp.mail.uucp
Subject: Re: Using UUCP over international phone lines
Keywords: satellite packet-size acknowledgment delays
Message-ID: <1991Jan25.214706.185@spock.UUCP>
Date: 25 Jan 91 21:47:06 GMT
References: <267@fgh.fgh.oz.au>
Reply-To: lancelot@spock.UUCP (Thor Lancelot Simon)
Organization: Choate Rosemary Hall, Wallingford CT
Lines: 44

In article <267@fgh.fgh.oz.au> michael@fgh.fgh.oz.au (Michael Coyne) writes:
>I am using UUCP between two 4800 baud MNP4 modems - one in Holland, and
>the other in Sydney, Australia.  My effective throughput is only about
>2400 baud.  I suspect that this is due mainly to UUCP using a small
>packet size, with relatively frequent pauses to wait for
>acknowledgments which have to travel halfway around the world.

If you're sending megabytes of data, I would assume you're compressing it.
But MNP is not really 4800 bps.  It is 2400bps with a data compression
scheme which will get, *at best* 4800bps throughput.  If you're sending data
that is already compressed, throughput should drop to BELOW 2400 bps.  The only
reason it wouldn't is that MNP makes slight improvements on 2400 bps using a
link scheme that eliminates stop bits.  If you stop compressing your data on
the sending host, throughput will rise, but the files will be proportionately
larger, and your compression at the sending site is probably superior to the
modem's.  To me, MNP modems have always been a fairly obvious waste of money
if used for file transfer - I can do far better compression before I send the
data, and only have to buy a 2400 bps modem.

>2. Use a completely different file transfer protocol.  Does GNU have a
>UUCP look-alike?

There are other UUCP protocols.  You'd probably want e or f protocol. x
protocol, to my knowledge, doesn't work.  One of e and f does NO 
error correction, and I wouldn't use it even over a reliable link unless I
was sure that no data could get lost along the way.  Berkeley t protocol is
similar, because it depends on TCP/IP to keep track of the data.  What I would
suggest, however, is that you look into some of the less often used options
on Chuck Foresberg's RZ/SZ programs, some of which can perform uux-like 
functions.  If you can get it working, I think you'll far prefer Zmodem to
any of the UUCP protocols.

>Michael Coyne                              FGH Decision Support Systems P. L.
>ACSnet:   michael@fgh.fgh.oz               Suite 101, 77 Pacific Hwy,
>Internet: michael@fgh.fgh.oz.au            Nth. Sydney.  2060.  Australia.
>UUCP:  uunet!fgh.fgh.oz.au!michael         PHONE: +61 2 957 4224



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*Thor Simon             * Okay, just a little pin-prick...There'll be no more-*
*lancelot@spock.UUCP    * Aieeeeaaaugh!-but you may feel a little _sick_.     *
*uunet!hsi!yale!lancelot*   ---Pink Floyd                                     *
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