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From: sl@van-bc.UUCP
Newsgroups: comp.dcom.modems
Subject: Re:  9600 bps dialups (HST 9600)
Message-ID: <786@van-bc.UUCP>
Date: Wed, 3-Jun-87 20:32:59 EDT
Article-I.D.: van-bc.786
Posted: Wed Jun  3 20:32:59 1987
Date-Received: Sat, 6-Jun-87 03:38:59 EDT
References: <8706030112.AA12502@mimsy.umd.edu>
Reply-To: sl@van-bc.UUCP (Stuart Lynne)
Distribution: world
Organization: Public Access Network, Vancouver, BC.
Lines: 32

In article <8706030112.AA12502@mimsy.umd.edu> mgrant@MIMSY.UMD.EDU (Michael Grant) writes:
>>It wouldn't surprise me if the HST becomes the defacto standard for 9600 baud.
>>--Keith Petersen
>
>I would be surprised.  Even though I usually don't require more than 300 baud
>to type at a terminal, my systems support UUCP which wouldn't work very well
>with 300 baud in one direction.  Do these modems do some sort of flow 
>analys and adjust the speed accordingly?
>
>I feel that the only good 9600 baud modem is one that provides at least a
>full 9600 baud in both directions, with NO egregious delays.
>

I disagree. 

Remember the total bandwitdh available to you must be subdivided into two
channels for bi-directional use. So to get two times 9600 bps you must have
an effective channel bandwitch of 19.2 kbps. 

Now for file transfers with 95 % of the total traffic in one direction. I
would far rather take my 19.2 kpbs channel and have (for example) a 18 kbps
channel for the file xfer, and 1.2 kbps for the return acks. This gives me
almost double the throughput. 

There are very few file xfer protocols which allow simultanous bi-directional
file transfers. So why waste all that bandwidth. 

If as I suspect, uucp acks get through on the 300 bps channel of the HST
modem then it will provide about 880 cps throughput on file xfers.

-- 
Stuart Lynne	ihnp4!alberta!ubc-vision!van-bc!sl     Vancouver,BC,604-937-7532