>older releases needed the "i" before the 10 digit number in the incoming call route
The i changes the number plan characteristics for the CPN element of the ISDN messaging. This is not verison dependant, but depends on the requirements of the carrier.
>BT charge a small charge to transmit a DDI from the list of DDI's
Never heard of that (doesn't mean that it isn't true) in my experience BT don't charge for outbound CLI, but do charge for the ability to receive inbound CLI
>The number of digits in the incoming call route has no bearing on whether the DDI is displayed on outgong calls.
Not entirely true; BT will use between x and 10 digits for outbound CLI where x is the number of DDI digits in use. That is if you have 6 digit presentation, BT will accept 6,7,8,910 digit for outbound CLI, but not 4 or 5. I have encountered BT circuits (particularily BRI) where they require 10 digits and nothing else will work. I suspect that this is where BT have screwed up the datafill for the circuit - and I think use Point to Multi-point instead of Point to point (One shouldn't give you DDIs)
Take Care
Matt
I have always wished that my computer would be as easy to use as my telephone.
My wish has come true. I no longer know how to use my telephone.