Callerid name is one of the few significant technical differences between Canadian and US phone networks. In the US, just the callerid number is passed between carriers. When the service provider of the calling destination receives the call, it looks up the callerid number in the CNAM database if the end subscriber pays for the callerid name service. This lookup provides the registered callerid name, that is then supplied to the end user. There is a charge for each CNAM database “dip” of around half a cent that goes from the telco that does the lookup to the telco that registered the number in the CNAM. (Incidentally, some telcos will share this dip revenue with the caller, opening up an interesting revenue opportunity for call centres with high volume dialers.)
The Canadian process was defined by Stentor in 1993 when the callerid name feature was first introduced. In Canada, the callerid name is sent by the calling party along with the number, and and passed through to end receiving party with no need for a lookup. Just like callerid number, for calls initiated on PRIs, the callerid name can be set on a call by call basis.
Origination and termination that passes through US voip providers often does not relay the callerid name for Canadian traffic. At Canadadids, we provide callerid name and number on all of our DIDs. On our Canadian termination, the traffic stays in Canada and the callerid name you set is passed on to the receiving carrier.