Xref: utzoo comp.dcom.modems:2529 comp.mail.uucp:1978
Path: utzoo!attcan!uunet!seismo!sundc!pitstop!sun!rayssd!galaxia!dave
From: dave@galaxia.zone1.com (David H. Brierley)
Newsgroups: comp.dcom.modems,comp.mail.uucp
Subject: Re: UUCP g stats
Message-ID: <514@galaxia.zone1.com>
Date: 27 Sep 88 05:11:19 GMT
References: <183@arnold.UUCP> <1988Sep20.184054.2403@utzoo.uucp> <184@arnold.UUCP>
Reply-To: dave@galaxia.zone1.com (David H. Brierley)
Organization: Dave's Very Own Personal System
Lines: 34

In article <184@arnold.UUCP> dave@arnold.UUCP (Dave Arnold) writes:
>(Henry Spencer) writes:
>> In article <183@arnold.UUCP> dave@arnold.UUCP (Dave Arnold) writes:
>> >seeing about 450cps, is something wrong, or is this average?
>> 
>> negligible -- they are substantial.)  Uucp-g can run a line at circa 90%
>
>I have never seen 90% bandwidth utilization.  My 3B1 at home running
>at 1200 baud always gets around 100-120 cps.  How are you computing
>
>(c * 8) / b
>where b = baud and c = chars. per second?

Dave, I dont want to sound demeaning but is your brain in a holding pattern
today?  The "baud rate" is not computed by multiplying the cps value by 8.
It is true that the baud rate represents the number of bits that flow through
the line each second but for every data byte you send there are more than 8
bits.  Each data byte is preceeded by (usually) 1 start bit and is then
followed by either 1 or 2 stop bits, thus making either 10 or 11 bits of info
for each data byte sent.  Most people configure their modems for one stop bit
and can therefore make the simple approximation of CPS = BAUD / 10.  Using
that formula you will see that 90% of a 1200 baud line is 108 CPS.  If you
are getting between 100 and 120 cps then you are doing pretty good.  The data
rate that you can achieve is very dependent on the machine you are using.
For example: I have two machines (VAX 11/78x) that are connected via a
dedicated 9600 baud line and I typically see between 400 and 600 cps.  I
have two other machines that talk to each other through a micom data switch
at 9600 baud and I consistently see between 700 and 800 cps.  Several of
our 9600 baud trailblazer links are capable of hitting 800+ cps if I send
them enough data to overcome the startup overhead.
-- 
David H. Brierley
Home: dave@galaxia.zone1.com   ...!rayssd!galaxia!dave
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