Carlos E. R. wrote:
I also have worked on that field, but not that long. My experience is with the 5EEE only. It is precisely due to that work that I became interested in Linux;-)
I have worked with a wide variety of systems, though not on the big phone switches.
Legislation in Spain is such that law insists calls are identified because it is needed to know whom to charge the phone call to, across different companies. It started when the government forced the only telco in existence here (Telefónica), in 1997, to accept indirect phone calls routed via another company (you prefix your call with a 3 digit number, and the call is routed via another telco for the long distance part).
The phone company can still identify the phone trunk a call came in to them on and use that for billing. However, they have no idea what may be connected to that trunk at the customer's end. It could be a local PBX or it could be extended just about anywhere in the world, by a variety of means.
I too have seen those strange numbers, like 000000, in my terminal, but unfortunately, after I stopped working there, so I don't have inside knowledge on them. I believe they come via internet gateways.
I know that with VoIP machines you have a lot of liberty, you can do anything with numbers and names and routings. It is up to you what you do or fake, which also kind of scares me.
Of course, the typical is having a company with two or more sites, and routing the call, inside your network, to the POT network from the site closest to the destination, so that the call is charged local charges instead of long distance.
That has been quite common for years. Also, the old "TDM" systems were also quite flexible, as I have mentioned, including giving whatever number to a phone. It's just cheaper and easier with SIP. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org