From owner-freebsd-questions Sun Feb 24 18:46:36 2002 Delivered-To: freebsd-questions@freebsd.org Received: from hk.com (ip-1-8-104-152.rev.dyxnet.com [152.104.8.1]) by hub.freebsd.org (Postfix) with ESMTP id 786F437B400 for ; Sun, 24 Feb 2002 18:46:33 -0800 (PST) Received: from ip-25-8-104-152.rev.dyxnet.com (ip-25-8-104-152.rev.dyxnet.com [152.104.8.25]) by hk.com (Postfix) with ESMTP id B667B1A6657; Mon, 25 Feb 2002 10:48:34 +0800 (CST) Date: Mon, 25 Feb 2002 10:46:22 +0800 (Taipei Standard Time) From: "Maren S. Leizaola" To: Joe & Fhe Barbish Cc: FBSDQ , Rod Person Subject: RE: SQUEEEZING the most bandwidth out of a 33.6 modem In-Reply-To: Message-ID: X-X-Sender: maren@leizaola.com MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Sun, 24 Feb 2002, Joe & Fhe Barbish wrote: | | | -----Original Message----- | From: owner-freebsd-questions@FreeBSD.ORG | [mailto:owner-freebsd-questions@FreeBSD.ORG]On Behalf Of Maren S. Leizaola | Sent: Sunday, February 24, 2002 11:04 AM | To: Joe & Fhe Barbish | Cc: FBSDQ; Rod Person | Subject: RE: SQUEEEZING the most bandwidth out of a 33.6 modem | | On Sun, 24 Feb 2002, Joe & Fhe Barbish wrote: | | V.90 & V.92 have fall forward and fall backward to handle changing line | conditions. I think you have missed the point of using s38. The conditions | of each individual phone circuit vary greatly. I personally doubt that the quality of channels on the T1 side of a 56K modem pool varies a lot. It is rare that a channel in the T1 will have problems. What I am sure is the analogue side of the connection typically of what is in ones home will vary a lot and the way it performs at different times. ie, when you have bad weather, do you think it is the T1 that is having problems or your end? | If the circuit is so poor when you dial in to your ISP that you only get | connected at 48000 the likely hood of it getting better during it's use | life time is very unlikely to none. By setting s38 to some minimum value | the modem hardware will hangup the poor circuit and get a completely | new, different circuit path each time it redials until it gets a connect | rate higher that the one you specified in s38. The key here is the new, | different circuit path which may have better or worse line conditions. | But the modem will keep trying until it finds a circuit the meets or | surpasses the minimum connection speed you want. No what you are really doing is redialing until your circuit is capable of handshaking at 52K in that specific time. In a way it is not a bad thing to do if your modem does not fall forward as expected, but don't expect to be running at 52K because you got the 52K handshake, because in a few minutes you will be down to 49.6K or lower if your line is not there. In HK we have a service where you can use your line to send a fax to a number. The system will pick up your number from your caller ID and give you noise level and a little graph of the noise you have on your line. One thing I did find when I ran the private wire was that if it had errors the circuit would slow down and would stay at lower speed. Then I would reset the modem and do a new handshake and go back to a higher speed. So if you want to persue this "glorious" 52K I would also combine what you say with a periodic (a couple of times per day?) hang up to make sure that some error did not make you fall down to 43K or less and you are stuck there. | Once the connection is made I know of no way to see the connect | rate on the fly. Ok. Maren. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message