> From: Shikhar Sarkar > > My question is: when sending SIP Invite, is there a way to > distinguish the > two cases. I checked in the SIP rfc and the only option I see is > "anonymous". > > So how to handle it?
I assume that you are referring to paragraph 2 of section 8.1.1.3 of RFC 3261. But it is clear from that discussion that alternative From headers could be used with similar effect -- such as 'From: "no caller ID" <[EMAIL PROTECTED]>' -- the protocol only requires that the From value be syntactically correct, and the semantics only require that the value not disclose the caller's identity. >From a system engineering point of view, there is no way to simulate the PSTN operation of carrying the caller ID through the switching system until the final switch, and then not providing the caller ID to the UA -- with SIP there is no way to predict the point at which the message will pass into a network under the recipient's control, at which point the recipient could extract the caller ID information. So the From value has to be an anonymous value when it is first generated. Dale _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
