Kirk Moir <moir@mprgate.mpr.ca> (06/12/91)
My complements to Brad on his efforts. This is an excellent account. Is it possible to supply information re the following questions: a) Who manufactured the "high capacity digital cross-connection system"? I am under the assumption that some kind of DCC switch died. Please correct me if required. b) What were the data rates of the affected 2800 services? 2.4Kbps, DS3, etc.? c) What kind of network management was in place to deal with this kind of outage? d) Did spare capacity exist? Could the trouble theoretically have been routed around or were most problems associated with non-redundant subcriber lines? Thanks in advance. Kirk Moir Voice: (604) 293-5375 MPR Teltech Ltd. FAX: (604) 293-5787 8999 Nelson Way Internet: moir@mprgate.mpr.ca Burnaby, B.C. CANADA V5A 4B5 (134.87.131.13)
Floyd Davidson <floyd@ims.alaska.edu> (06/14/91)
In article <telecom11.451.9@eecs.nwu.edu> phil@wubios.wustl.edu (J. Philip Miller) writes: > Kirk Moir <moir@mprgate.mpr.ca> writes: >> a) Who manufactured the "high capacity digital cross-connection >> system"? I am under the assumption that some kind of DCC switch died. >> Please correct me if required. > Very conveniently, none of the press accounts have given any real > information. In the Sunday paper account (front page of business > section) there was a picture of the "computer". It appered to be rack > mounted, perhaps 6' tall and 6-8' long. All one could really see was > that it appead to have many similar shaped "modules". > Could it have been ISDN service? Maybe a little explaination of what a "digital cross-connection system" is would help. Several companies make them. AT&T calls theirs a DACS and the particular one where I work is called a DEX (made by DSC Communications Corp.). There are others. It is basically a digital switch. Except it does not decide which lines to connect by looking for touch tone and it does not provide dial tone or any of the other services that come with a digital "switch". The connections are set up at a console, or any number of them, and remain in place until they are changed or removed by software commands. The outside world is interfaced via T1 carrier. These systems are used to cut down the amount of time and manpower it takes to wire circuits up on distribution frames. Instead of running wires, the craftsman just enters commands in the computer. Obviously at some point each circuit is in fact likely to end up going analog on a copper wire circuit, so not all wiring is eliminated. But for circuits that pass through an office where the carrier it rides is digital on both sides, there is no wiring done at all. It also has the advantage of remote access via modem. And a circuit can be bridged to test equipment that is also remotely controlled via modem, thus permitting circuit testing at an unmanned location by someone at a central control/status center. I have no idea how many testboard craftspeople have been laid off since this device has come into use, but ... Floyd L. Davidson | Alascom, Inc. pays me, |UA Fairbanks Institute of Marine floyd@ims.alaska.edu| but not for opinions. |Science suffers me as a guest.