Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!ccicpg!uis-oc!ns!bob
From: bob@ns.UUCP (Bob Mathias)
Newsgroups: comp.dcom.modems
Subject: HST/V.32bis Performance
Keywords: v.32bis HST Performance
Message-ID: <139@ns.UUCP>
Date: 24 Feb 91 18:06:18 GMT
Reply-To: bob@ns.UUCP (Bob Mathias)
Organization: Unisys Corporation; Irvine, California
Lines: 34

I have noticed that with my new USR DS modem, that HST mode seems to 
outperform v.32bis when doing file transfers using YMODEM-G on a PC-based
BBS.  I run both with v.42 and v.42bis is disabled.  The speed difference
is about 30cps.     

I'm not really concerned about this speed differential since it is not that
great and I'd rather use a non-proprietary protocol.  I am just curious as
to why this might be.

I have come up with some scenarios:

	1)  USR has done HST for years, thus they have fully optimize
	this protocol while v.32bis is new and thus not optimized.

	2)  HST might have an inherent advantage when doing a one-way
	type file transfer that depends upon the error correction
	protocol.
	
	3) Operator error (mine!).  I don't think this is the case, but
	one never does!  I've looked at the ati 6 screen after each
	connection, and this indicates that I am running in the modes
	I requested.  (The basic difference I do between running the
	two protocols is changed the Bx parameter: B0 = v.32bis and 
	B1 = HST.  And yes, the BBS I am connecting to is another 
	USR DS (w/ v.32bis).

Anyone else with an explanation?

 
-- 
Bob Mathias                          uucp: ...!uunet!ccicpg!uis-oc!ns.UUCP!bob
Unisys Corporation                   CServ: 70340,165 
A and V Series Systems Engineering   voice: (714) 727-0323  
Irvine, California