Path: utzoo!utgpu!watserv1!watmath!att!att!linac!uwm.edu!wuarchive!usc!apple!bionet!hayes.ims.alaska.edu!accuvax.nwu.edu!nucsrl!telecom-request From: mitel!spock!grayt@uunet.uu.net (Tom Gray) Newsgroups: comp.dcom.telecom Subject: Re: New Area Codes and Intl. Dialling Message-ID: <14993@accuvax.nwu.edu> Date: 27 Nov 90 12:10:04 GMT Sender: news@accuvax.nwu.edu Reply-To: Tom Gray Organization: Mitel. Kanata (Ontario). Canada. Lines: 57 Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 10, Issue 849, Message 6 of 10 In article <14934@accuvax.nwu.edu> U5437880@ucsvc.ucs.unimelb.edu.au writes: >In article <14680@accuvax.nwu.edu>, og@chorus.fr (Olivier Giffard) >writes: >> I've just tried to dial a number in the 917 area code (non existent >> yet) from France. I got a French intercept message just after dialing >> the 7 of 917 saying that this code was not in service. What means has >> a switch in France to know that. There must be some kind of table to >Why is there an intercept? So the company which catches the wrong >number does not have to foot the bill for bandwidth to find out the >number is not connected. Invalid area codes are the simplest to >check, since they change slowly, and there is a relatively small >number of valid possibilities. >Try dialling 19 44 81 603 xxxx, and see if you get a French intercept. >[Moderator's Note: I just now tried it from Chicago, USA. It accepted >the entire number (that is, 011-44-81-603-four more), and the response >to me on each of several attempts was the same recorded announcement: >You call cannot be completed by the telephone company in the country >you are calling at this time. Please try your call again later." >Interestingly, my call had left Chicago, gotten out of the USA and was >sitting in limbo somewhere. Instead of playing the French recording to >me, when AT&T heard something 'go wrong' over there, it yanked the >connection back and played an English language message instead. PAT] There may have been a combination of factors going on here. When you reached the international network, a different type of networking (siganlling) exists than that usually used in the US. When you siganlled the French network with your originate, there was probably an English language source signal in the message. Thus you could have been connected to an English language recording in France because of this. More likely, the originate message for your call, was answered with a reply of "non-existing number" from the French network. The US side gateway switch (international) then would have terminated the call on a recording without wasting transatlantic bandwidth. I wouldn't know the precise signalling scheme used on your call but the CCITT signalling scheme R2 provides all of these services and is used on international calls. In any event, it would have been the gateway switch on either side of the Atlantic that would have intercepted your call. The national signalling systems in both countries are separated by the gateway. Any reply from the French network would have been meaningless to the normal ATT network. ATT would have completed your call to the US gateway and then turned control of your call over to the gateway. The US gateway would signal the French gateway which will in turn control the setting up of the call in France. With multiple connections it is possible that the gateways will signal between themselves with tones which are meaningless to the national networks. This always seems like the gateways are using the national networks as large PBX's to me.