Thank you, thank you! That was incredibly helpful. I always wondered how to get info out of the modem.
I went to the signal page on the modem and got -9 dBmV reported Downstream Power Level. Since this is well outside the +3 to -5 dBmV range given in the report, I called ATT technical support. They had me powercycle the modem, which got me up to -8 dBmV (which promptly, within a few minutes, dropped back to -9 dBmV). The Upstream Power Level is well within range (35 dBmV), but I don't know what to make of the signal to noise ratio at 35 dB. Is that excessive? I've looked for specs on what it should be, but I can't seem to find anything from ATT (and the tech had no clue. So now my problem, apparently, is how to get the signal boosted. I asked the tech about sending someone to amp the line. Here, roughly, is the conversation. "If it is deemed necessary to put an amplifier on your line, then we will send someone out to do so." "So, like, when is it deemed necessary?" "IF it is deemed necessary, we will send someone out." "And we know it's necessary when..." "Give us a call if you have any more problems, however I must tell you that we do not support linux, and that is probably your problem." Doh! Yes, I'm an idiot. Will someone kick me in the head, please? I did, indeed, mention the "L" word. I'd no idea that all the stories about hostile unhelpful reactions were true. I thought maybe times had changed. So now what should I do? I need a white-paper specifying acceptable power and noise ranges. Are there any helpful ATT techs out there with this info? Where is the "DSL Reports"? I suppose I could put the modem on a win95 box and start screaming bloody murder at ATT. Best, Don > I've tried all you suggest but a new NIC or a new > cablemodem. The SB4100 is the SB3100, but with > a USB port (unused) and a "standby" switch on the > front. Otherwise the units are identical, so unless mine > is bad (a possibility -- but how to test the unit?), I don't > think I just ran across this post at DSL Reports: ******** "You can check various diagnostics for the 2 way surfboard modems here 192.168.100.1/" This is the page we, as technicians, pull up. I really tells a lot. Especially the SIGNAL page. ยป192.168.100.1/signal.html What you are looking for is DOWNSTREAM POWER LEVEL. This is the level coming INTO the modem. YOU WANT THIS VALUE BETWEEN +3 AND -5 dBmv. Also look at UPSTREAM POWER LEVEL. This is showing how hard the modem is working to "get out" of your home. You want this maybe 55dBmv or below. Any higher is saying the modem is struggling to get out. This can be due to old cable in house. OR... The most common reason... Road runner is going through more than one splitter. Roadrunner MUST be connected via dedicated cable line. Meaning, when the cable comes in at outside of house... Roadrunner must split at a two way splitter and go straight to modem. ******** He mentions Roadrunner, but the other information may be applicable to you (assuming you've got something other than RR). Hopefully the 'signal' page will be quite helpful. Good luck Hall
