Thanks for the reply Rob, When I was working with multitech a long time ago on some analog modems made by them, we started playing around for with the power levels in an effort to solve connection problems ( the same long training and then no connect or the dropped connection ) The only explanation I ever got out them was something to do with the way the phone co. provisioned the line and whether or no they added padding to them. Apparently some do some don't. Padding on ct1s is out my experience range so I took their word for it. But there must some way to check this, either a measurement made directly on the line or a indirect method by querying the modems somehow. A 3com tech I tallked to once made reference to reading this info directly off the dsp by plugging in a console cable to them. He never did make it out here on-site, so his knowlege was lost to wind.. Oh well.. -----Original Message----- From: owner-usr-tc@lists.xmission.com [mailto:owner-usr-tc@lists.xmission.com]On Behalf Of Rob Nelson Sent: Sunday, January 09, 2000 11:17 AM To: usr-tc@lists.xmission.com Subject: Re: (usr-tc) Second request --dsp transmitter levels Terry Kennedy wrote:
A few revisions back, can't remember how far, the dsp code started to allow setting of the transmiter power levels. This was under line interface options, transmitter level (-db), the same as the quads used to have. They also had the same -11db setting as the quads did. I have had better luck with the quads ( and some old analog multitech modems ) by lowering the power level to -13db. It helped two different problems, disconnects and the long training sessions that never would connect. I was about to start changing these levels to -13db when I noticed that 3com has changed the default setting from -11db to -10db in 2.0.51. In all previuos releases they were set at -11db. Anyone out have any input on this? Does anyone know how to get measurements from the ct1s to determine what the correct level should be?
I changed our DSP's to -13db when I read the following in the release notes for 2.0.81 <quote> Adjustable Transmit Level Adjustable transmit level provides the ability to configure the modems for optimum performance. Ranges: -3 to -30 dBm for digital T1 line sources. A setting of -13 dBm (S39=13) is recommended for calls over digital lines (T1 or PRI). </quote> We have seen no ill effects from this setting. We had problems with what you describe above, long training sessions that wouldn't connect. I don't know yet if this setting has made an improvement. What I would like to know is why the recommended setting is not the default setting? - To unsubscribe to usr-tc, send an email to "majordomo@xmission.com" with "unsubscribe usr-tc" in the body of the message. For information on digests or retrieving files and old messages send "help" to the same address. Do not use quotes in your message. - To unsubscribe to usr-tc, send an email to "majordomo@xmission.com" with "unsubscribe usr-tc" in the body of the message. For information on digests or retrieving files and old messages send "help" to the same address. Do not use quotes in your message.