revell@uunet.UU.NET (James R Revell Jr) (12/29/90)
In article <1990Dec28.045029.9006@bilver.uucp> bill@bilver.uucp (Bill Vermillion) writes: } I have a T2500 rev 7 roms, he's using a tb+ rev 4 roms. I can call } him, and uucp transfers do fine. } } He calls me, and the modems seem to train forever, the normal low } speed gets going, then the moose calls start, they talk a bit, and } then I seem to send some tones and it starts again with the PEP } calls. It continues for about 15 seconds until he times out. Are you calling long distance and using different LD carriers (my bet is he uses MCI, maybe Sprint, and you don't)? Do you also have S120 set to 16 or 28, thus disabling the fix for echo cancellation in your T2500? Based on problems I've dealt with over the last 10 days I am getting the impression that MCI may have started the same echo cancellation deal that Sprint did late last winter. There are other symptoms caused by this problem I haven't noticed yet, but the long retraining at start of call is the first symptom I saw last time too. If I'm right this is going to be a big problem for lots of people soon. I encourage any UUNET subscriber who experiences similar problems to send mail to uunet!postmaster. I'm particularly interested in whether you use MCI when seeing this problem. Other symptoms of this problem may include extremely low throughput and a dramatic increase in failed connections. } Bill Vermillion - UUCP: uunet!tarpit!bilver!bill -- James Revell senior uunet postmaster <revell@uunet.uu.net> /8^{~
csg@pyramid.pyramid.com (Carl S. Gutekunst) (12/29/90)
Just as a datapoint, when Pyramid switched from AT&T to MCI long distance, we saw a significant drop in throughput. I did a bunch of S71 and S73 spectrum plots, and noticed what appeared to be fairly uniform degredation across the spectrum; effect on bandwidth was variable. I really don't think echo cancel- ation had anything to do with it; fiddling with the appropriate registers on the TrailBlazer, per Telebit's suggestion, only make it slower. (One of those things: When I was able to make a monetary case for going back to AT&T, no one in the Telecom department was very interested. Now that AT&T is Pyramid's largest customer, I notice that AT&T is also once again our long distance carrier. :-) ) <csg>
bill@bilver.uucp (Bill Vermillion) (12/29/90)
In article <116057@uunet.UU.NET> revell@uunet.uu.net (James R Revell Jr) writes: >In article <1990Dec28.045029.9006@bilver.uucp> bill@bilver.uucp (Bill Vermillion) writes: >} I have a T2500 rev 7 roms, he's using a tb+ rev 4 roms. I can call >} him, and uucp transfers do fine. >} >} He calls me, and the modems seem to train forever, the normal low >} speed gets going, then the moose calls start, they talk a bit, and >} then I seem to send some tones and it starts again with the PEP >} calls. It continues for about 15 seconds until he times out. > >Are you calling long distance and using different LD carriers (my bet is >he uses MCI, maybe Sprint, and you don't)? Do you also have S120 set to >16 or 28, thus disabling the fix for echo cancellation in your T2500? No - he's about 10 miles away, and it's the same phone company. However, I did get an email that the way to fix it is to upgrade the tb+ to version 5.1 ROMS. This is supposed to be a known problem. I was also told that there is a hidden register to put the v.32 tones at the end - this is what appears to confuse the tb+. Will keep you posted. Thanks. -- Bill Vermillion - UUCP: uunet!tarpit!bilver!bill : bill@bilver.UUCP