kravitz@ucsd.edu> (06/12/90)
This afternoon I had the pleasure of having the cook's tour of a local firm called "Primary Access". A friend of mine works there, but was unable to give me the big picture of what they are doing over the phone. The cook's tour fixed that. I was impressed enough by what they are doing that I invited the the V.P. of Engineering (Jim Dunn) to have a guest account on my system in the hopes that he will participate in the TELECOM Digest. Imagine a computer service provider with racks full of hundreds of modems. All those pairs coming in from the CO are a maintenance nightmare. The computer service provider could bring in the lines as T1, set up a T1-to-analog channel bank and hook his modems up to the channel bank. Less noise, less wires. But modems process the signal by PCM encoding the audio and applying a digital signal processor (DSP) to the digitized audio. We just took the PCM signal from the CO (from the T1 line) and turned it into audio in the T1 channel bank..... Primary Access makes T1 channel banks which have "DSP cards" instead of standard audio "line cards". When downloaded with the correct software, the DSP cards become modems. The PCM data from the T1 line is sent directly to the DSP without ever turning it back into audio. Not only do they get superior noise immunity, but they can also do things like ANI capture on the incoming calls. Their product line will include V.22bis and V.32 support, X-25 PAD, and a whole bunch of other things; I've not read far enough into their literature yet. There are menu driven configuration and logging functions available via an IBM PC or Clone. These functions can be performed remotely. The system claims to be cost effective at 7 or more ports, with a payback period of between three and eighteen months. Jody Internet: foxtail!kravitz@ucsd.edu uucp: ucsd!foxtail!kravitz [Moderator's Note: Thanks for the introduction. In fact, Mr. Dunn sent an article which is included in this issue. PT]