Issue with Withheld or 'No Number'

Feb 27, 2016 at 5:12 PM
If caller's number is withheld then the value of sipRequest.Header.From.FromName is own number. I can manually check if it matches own number and assume it is withheld. But is it supposed to be that way? What about when the incoming number is blank. I have not managed to test with blank number yet but i know that occasionally it does happen.
Feb 29, 2016 at 8:08 AM
If you're referring to an incoming INVITE request then the caller sets all the fields. If the FromName happens to be set to your number/username then it's because that's what the caller set. It's a bit strange that they would do that since that's typically what the To header is for.

With SIP calls there is no such thing as CallerID, number withheld etc. Typically you just have the From header that contains all the information the caller is willing to supply. In cases where a SIP Provider is forwarding calls from a PSTN gateway it's up to them how if and/or how they decide to map the PSTN CallerID to the SIP headers but again it's typically done with the From header. Occasionally you'll get headers like P-Asserted-Identity getting used for CallerID but that's not very common.