Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!accuvax.nwu.edu!nucsrl!telecom-request From: Dick Jackson Newsgroups: comp.dcom.telecom Subject: Re: ISDN In My Ole House Message-ID: <2476@accuvax.nwu.edu> Date: 29 Dec 89 16:33:13 GMT Sender: news@accuvax.nwu.edu Reply-To: Dick Jackson Organization: Citicorp/TTI, Santa Monica Lines: 35 Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 9, Issue 600, message 5 of 9 In article <2440@accuvax.nwu.edu> hui@joplin.mpr.ca writes: >X-Telecom-Digest: Volume 9, Issue 598, message 3 of 9 >Lucky us in this city are slated to get ISDN in two years. >I believe it requires two twisted pairs to each phone within the >house. I wonder whether my current house wiring of standard four >conductor cable to each modular phone jack will be adequate, or will >the wires have to be replaced with special controlled impedence wiring >when I order ISDN? This whole subject has been puzzling me. The standard model for premises ISDN is an NT1 hooked to a station via the two-pair S interface, or to multiple stations (up to 8) via a passive bus version. Since most homes now have multiple phones, the first thought is to have passive bus wiring. But each station is different logically I believe and only one phone can use a B channel at a given time (no "conferencing"). Unless I have some deep misunderstanding, it seems that the simple model will not serve a multi-phone house very well. I suspect that in practice people will choose to buy NT12 units. The NT2 portion of these will effectively be a PBX and in addition can support an R interface (one pair analog) to existing POTS phones for those who don't want to replace all their current phones with $500 ISDN sets and also rewire their homes. Such NT12 units are likely to be expensive, especially at first, and this is another reason why I am pessimistic about ISNDN service catching on for residential use. Dick Jackson