atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Telecom Service & Providers PRI and CID questions

Hello all-
Here at UT we have a large NEC system, a NEAX I think. Almost every phone on campus (the exception is house phones in common areas of buildings) has a DID number, they have one entire exchange here and part of another. Anyway, something I don't understand is why each phone does not give out its DID number on caller ID. Say someone calls my cell phone from a campus phone. It will either say unavailable, or give a few point numbers that don't translate to an actual extension. So when my boss calls me from his office, it just comes up as an unavailable call, so I don't know who is calling me. I am curious if anyone knows why they might have it set up this way.

Jeff it all has to do with what the PBX is sending and how it is set up. It may be set up to just send out the BTN. If yiou were to send each DID, each one of those DID's then need to be assigned in a Cnam database so the carrier knows what name to send with the number. In your case they are probable only sending the main dn of each trunk group.

As far as the name goes, I would assume it would just say University of Toledo for all of them, if they did it that way. I should try having someone call me at a landline with CID so I can see what name comes up if any.

Anthony pretty much nailed it. ANIs can be either sent by the PBX to the service provider via the "D" channel, or trunk groups can have specific ANIs assigned to them.

On the CID issue, your PBX can send a CID number or the Telco will attach the BTN to the call. Generally the PBX has to have each extension programmed with the outbound caller ID digits for its calls. Otherwise the PBS default or telco default will attach to the call.

CID Name is a lookup at the receiving end of the call. The called party's telco can look up the CID digits in one of 3 databases to find a display name. If they don't look it up or your number is not listed in the database they use the called party will see "unavailable", or "Ohio Caller".

Getting your number and display name listed in the databases is up to your telco. Usually they are pretty good about it and some are just a PITA about it.

If you every have a customer signing a new PRI contract with lots of DID's get that noted in the contract before they sign to be sure it will get done.