>From the perspective of a tech at the local phone company. Here in the USA there was, when it hit our area, AMI Lucent protocol ISDN. It was a failure for Lucent because they lost the battle to set the standard. AMI cards were pulled and replaced by the newer cards which the name of escapes me at the moment. These cards in the lucent 5ESS became what was used. Yes, ISDN sat in my office for 2 years before the first customer, a Test phone in my office was used. ISDN became popular for banks to use as dialup backup for T1 systems prior to Broadband. It also became popular to purchase up to 5 ISDN lines for video conferencing. I speak from the knowledge I know and the US and Canada most likely have the same ISDN. I remember SPID base, but all ISDN lines I dealt with had SPIDS 2 of them if I remember correctly. In some cases we would deliver 3 ISDN lines. Each one had one SPID, but it would bond the 2 lines for 128 service. Other times we HAD to deliver 6 SPIDS on three lines because the gear in the field did not work the other way. The gear wanted 6 SPIDS from 3 lines. We also were the only ones that we were aware of to provide CUSTOM ISDN as compared to NATIONAL. The differences were simply the layers of protocol, not much else except anything made for National only would not work on our CUSTOM network. National came along and it was simply a software change in the switch and we were now able to handle both types. Many many times I worked with vendors of video conferencing equipment that hassled for hours with their gear and finally called into our support center looking for help at the last minute. I repaired so many of these and these guys were trying to tell me how to set things and I would tell them if they wanted it fixed to listen and do as I instructed. They did and within minutes they were up and running. A call was placed to our center as we had a setup of 3 lines to test with. ISDN as far as the system that provides it and based in the USA is pretty much the same. The protocol is a standard and there are a couple variations. My ISDN test set by TEKTRONICS only handled the 3 from LUCENT, SIEMANS and Nortel. The list did not have any other types. Still in the end, one got 2B+D service, the ability to have 2 lines on one pair of wires and outband signaling. The ability to bond five lines providing studio level video and audio at 640K service was state of the art. This is what was of the day. ISDN could be configured a number of ways to provide low cost service. The T1 became the standard because of its stability and ease of providing over fiber. ISDN went by the way side. Xerox Corporation used ISDN heavily over the years so much that a remote switch was provided with them on their own property. Many ISDN phones were used in the day. So the service was always good, and in some cases eliminated the need for a on-site PBX, was tied with voicemail and auto attendants provided by the local CO. It's not really old school, just a technology that did not seem to take off in the states as it did in Europe. I believe that ISDN given a chance to have decent sales people schooled in its ability would be a great second and proven service for customers on a budget. VoIP still sucks and is by far crappier than ISDN on a bad day.
-----Original Message----- From: kxt-boun...@kxthelp.com [mailto:kxt-boun...@kxthelp.com] On Behalf Of wb8foz Sent: Saturday, September 24, 2011 15:19 To: kxt@kxthelp.com Subject: Re: KX-T: KX-TDA30 and BRI ISDN > Old school While you may feel this way, and it was a residential marketing failure in the US; where it is used, it's a major success. It does things POTS never could. One is deliver clean solid audio over 40 Kft of crap OSP that Verizontal can't/won't keep balanced. Another is deliver multiple DN's over a pair. > Actually ISDN is the same just about anywhere. ISDN is far from the same everywhere. While you are correct that there are 3 flavors in North America; they are wildly different from the EuroISDN protocol. It's not clear to me that the 30 supported (NA) SPID-type ISDN at all; hence my query. _________________________________________________________________ KX-T Mailing list --- http://kxthelp.com/ Subscription changes: http://kxthelp.com/mailman/listinfo/kxt _________________________________________________________________ KX-T Mailing list --- http://kxthelp.com/ Subscription changes: http://kxthelp.com/mailman/listinfo/kxt
