Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!apple!voder!pyramid!csg From: csg@pyramid.pyramid.com (Carl S. Gutekunst) Newsgroups: comp.dcom.modems Subject: Re: echo cancellation & Telebits (WAS: tb2500 to tb+ connect problem) Message-ID: <139159@pyramid.pyramid.com> Date: 29 Dec 90 01:56:18 GMT References: <1990Dec28.045029.9006@bilver.uucp> <116057@uunet.UU.NET> Organization: Pyramid Technology Corp., Mountain View, CA Lines: 13 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. :-) )