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GTD · 20-01-2005, 16:19

For clarity, when you make a phone call the telephone exchanges in the UK will communicate using a C7 messaging system to set up the call. Once the call is connected the C7 link is dropped and the exchange sets up a voice circuit to carry the voice traffic to call completion (or Data traffic etc). Also, a timer begins on the originating callers exchange detailing time call commenced, originating and dialled number as well as some additional header info (the timer and info creates a Call Data Record - CDR which is linked to the retail billing systems to create the customer bill).
It is not possible on these exchanges to use the signalling system to inject any false data streams and corrupt the billing records being created for the call.
Also bear in mind that you need to be the call originator to incur a billing charge.

20-01-2005, 16:19	#25
GTD Inactive Join Date: Nov 2004 Location: Portsmouth Area Services: Phone, TV & 750k BBand Posts: 13	Re: mysterious calls For clarity, when you make a phone call the telephone exchanges in the UK will communicate using a C7 messaging system to set up the call. Once the call is connected the C7 link is dropped and the exchange sets up a voice circuit to carry the voice traffic to call completion (or Data traffic etc). Also, a timer begins on the originating callers exchange detailing time call commenced, originating and dialled number as well as some additional header info (the timer and info creates a Call Data Record - CDR which is linked to the retail billing systems to create the customer bill). It is not possible on these exchanges to use the signalling system to inject any false data streams and corrupt the billing records being created for the call. Also bear in mind that you need to be the call originator to incur a billing charge.