Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!gem.mps.ohio-state.edu!ginosko!brutus.cs.uiuc.edu!apple!ames!sgi!daisy!pkl From: pkl@daisy.UUCP (Peter K. Lee) Newsgroups: comp.dcom.modems Subject: Re: TB+ Performance [Was: Trouble with TB Plus (Please Help!!)] Message-ID: <3655@daisy.UUCP> Date: 25 Sep 89 18:04:30 GMT References: <132@clleth.UUCP> <235@tabbs.UUCP> Reply-To: pkl@daisy.UUCP (Peter K. Lee) Organization: Daisy/Cadnetix Corp., Mtn. View, CA Lines: 28 I posted the original request on TB+ performance over trans-atlantic phone lines. I finally decided to call up Telebit technical support to get help. I called up Telebit technical support to get help. The guy was real helpful in trying to decipher the S registers. The few useful ones are S70 and S72. They contain the instantaneous send and receive line speeds. My S70/S72 registers are 8000+ which should give me at most 800 cps. I tip to the other site, +++ back to my local modem and then dump S70/S72 to see what line speed I have. I get this without setting either S120 or J6S36 registers. Setting these registers don't seem to make much of a difference, so I may as well use the modems in a "standard" configuration. One other possibility is retraining. When the noise level changes too much, the modem will retrain itself. You will see the RD/SD lights went off for 8-10 seconds, it means that the modem is retraining. That will kill the performance. I don't see much retraining on mine, but it does pauses for 2-3 seconds quite frequently. Telebit says that it is not retraining, but waiting for buffers to get flushed out. My transfer speed also varies a lot. The fastest that I've ever got is 700+ cps for a 60K file. Thanks to all those who have responded (by mail or followup). -- -- Peter K. Lee (...!uunet!daisy!pkl), Daisy/Cadnetix Inc.