Obihai team,
You guys may not be familiar with some of the telephony standards in Canada. This might be a good reference for your software engineers.
Copied from here (
http://www.ainslie.org.uk/callerid/cli_faq.htm#Q_7 )
7. I'm in Canada, why doesn't my Caller ID work?
Yes, there is a country where things are more complicated than the UK. Most people think that Canada uses Bellcore, just like the USA. It does - almost. For some reason, the former Stentor member companies use a non-standard implementation of MDMF. Bellcore uses DN (Directory Number), usually the 10 digit number that includes the area code found in the phone book. Stentor uses DDN (Dialable Directory Number), a variable length number that is the number that must be dialed to call the other person
back (ie local calls don't include area code, long distance includes the preceding "1"). Normal Bellcore MDMF identifies each part of a message with a Message Type Word parameter, and the DN is assigned Parameter Type 02. The Canadian Stentor switches assign DDN to 03.
This is incredibly confusing for anything that only looks for the DN in 02, and this includes Unimodem (see below). Some modem drivers (and Canadian phones and caller ID boxes) check for both DN and DDN and will display either - 3Com ones for instance (and is there a general patch, perhaps for Unimodem?). Otherwise, you just have to avoid TAPI and use software that specifically knows about this quirk - Identafone is one, but most Canadian authors seem to have found out about this the hard way ;-). The relevant document was called Stentor document ID-0001 "CALL MANAGEMENT SERVICE (CMS) CALLING NUMBER DELIVERY (CND) (Single and Multiple Message Format) Terminal-to-Network Interface". Following the upheavals in the Canadian telecom market it is now Bell Interface Document BID-0001 and will cost you CAN$50 to download. Incidentally, Stentor's standard also allows for a Parameter Type 06, which includes a flag that indicates that the call is long distance and CallerID is not available, but it may no longer be in use.
Reference sites with documentation for Canada:
http://www.bell.cdn-telco.com/bid/ (I think all Canadian standards are documented here)
http://www.bell.cdn-telco.com/bid/bid-0017.pdf <- This one specifically refers to CID standards in Canada
Hope this helps.