Xref: utzoo comp.dcom.modems:2524 comp.mail.uucp:1966
Path: utzoo!attcan!uunet!husc6!uwvax!rutgers!bellcore!clyde!watmath!onfcanim!dave
From: dave@onfcanim.UUCP (Dave Martindale)
Newsgroups: comp.dcom.modems,comp.mail.uucp
Subject: Re: UUCP g stats
Message-ID: <16257@onfcanim.UUCP>
Date: 25 Sep 88 19:14:13 GMT
References: <183@arnold.UUCP> <1988Sep20.184054.2403@utzoo.uucp> <184@arnold.UUCP> <1988Sep25.015301.768@utzoo.uucp>
Reply-To: dave@onfcanim.UUCP (Dave Martindale)
Organization: National Film Board / Office national du film, Montreal
Lines: 18

>90% of 1200 baud is 108 cps.  Back when most of our news traffic
>was at 1200, we saw uucp running at 109 +- 2 or so cps for hours on end,
>quite consistently, for most sites.

Uucico, unless you've modified it, always uses 64-byte packets.
The g-protocol header is 6 bytes, so if there are always characters
being transmitted with no "dead" periods, you would expect to see
64/70 = 0.914 of the modem bandwidth being useful data.

1200 bps = 120 cps; the "data" portion of this is 109.7 cps.  Any more
than this and you have inaccurate timing (i.e. timing a short file
when the last buffer has been written but not yet arrived at
the far end) or a too-fast UART clock.  Any less and the host is
probably not keeping up.

With modems like the Trailblazer, the limiting factor seems to be
hosts that can't handle continuous input and output at 19.2 Kbps
more often than the modems.