From: Russmill47(a)aol.com Date: Mon, 4 Oct 2004 12:37:40 EDT Subject: Western Union TWX V Diagnostic Control Panel To: cfandt(a)netsync.net Cc: rigdonj(a)cfl.rr.com When Western Union acquired the TWX network from AT&T, there was a need to build a new network that would allow Western Union to integrate the existing Telex network with the TWX network. Western Union designed and built the Digital Exchange Network (DES) for this purpose. DES was not the huge success that everyone hoped as there were many software problems that caused reliability and availability problems. The TWX V Concentrator was located at the edge of the WU Central Office network, usually within a couple of thousand cable feet from the serving Local Exchange (Bell) Central Office. Typically, these concentrators would handle up to fifty (50) TWX customers, handling all the edge interaction with the customer TWX machine on one side of the box with the rest of the box providing TDM services that consolidated the 50 customer signals into a single digital data stream. In small locations, which could be rental space in a telephone answering service location, there would be a single box. Medium size locations would have multiple boxes that would feed their digital signals to an intermediate box that would further Mux these separate digital data streams to a high speed (9600 bps) Paradyne Modem. The Diagnostic Control Panel was mounted at the top of the concentrator and was used to monitor the internal health of the box as well as provide information as to the status of the individual subscriber links and the high speed digital data link. The technology is state-of-the art early 1970s so you can look to processor speeds of 1-2MBps. A lot of this technology was designed and manufactured in Mahwah, NJ. This was the R&D headquarters for WU and just up the road from WU galactic headquarters in Upper Saddle River, NJ. Russ Miller <mailto:russmill47@aol.com>russmill47@aol.com WA3FRP