[asterisk-users] ISDN

[Wilton Helm]

>Why didn't BRI catch-on in the US?
I a word--greed.  It arrived shortly after divestiture when there was a lot of competition in the market and a dozen independent regional telcos.  Apparently they saw a huge cash cow for this data service and yet another competitive advantage to proprietary implementation details.  I used to live in GTE territory (now Verizon) and they were charging 2 cents per minute of connect time!  This was on top of monthly fees that were unreasonable to begin with.  I don't know if they have all caught on now and fixed it, but its too late now because most of the US has DSL which is 10x the data rate and supports VoIP for voice.

I'm fortunate here that Qwest has offered it for at least 10 years at rates comparable to two POTS lines and no per minute charges.  When I started using it, in my situation I got more features for less money than two POTS lines, which I would have needed instead.

The irony is that the direct cost (equipment) of ISDN is less per B channel than POTS.  Anyone who has ever compared the cost of digital versus analog station cards for a PABX, knows painfully the cost of supporting A/D conversion, 90 V 20 Hz ringing and even DTMF registers.  If they had wanted to the telcos could have made ISDN cheaper than POTS, still made money and moved technology forward in the process.

But to illustrate the mentality, GTE, who I mentioned above was serving the affluent community I was in with stepper switches in the CO until well into the 1980s!  They put tone to pulse converters in front of them (initially for an extra fee) so they could support DTMF.  Ironically they only put 600 ms interdigit time in the converters and the steppers could take up to 800 ms to find a link for the next digit, so the call failure rate ran 10 - 50%!  I ran a PABX at the time and we did our own tone to pulse conversion just to avoid that.  With 800 ms interdigit time we had at least 99% completion!

Wilton
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