Microsoft Releases Lync 2013 Headers for SIP Trunk Provider Billing
If you’re a SIP trunk provider, and want to have more granular billing capabilities, then this 12 page documentation may be of use to you. Microsoft has released a document showing the headers implemented in Lync Server 2013, and how they can be used to more effectively bill customers. RFC references for History-Info, Referred-By, and P-Asseted-Identity as well as configuration details and various scenarios are mentioned.
Simulring
Released on 05-03-2013, the documentation is available at http://www.microsoft.com/en-us/download/details.aspx?id=38820
So sad, MS still has no clue about SIP or how to read RFC’s.
P-Asserted-Identity is supposed to contain a verified identity. How could they guarantee the authenticity of the identity if they blindly forward it from an inbound call? The PAI must contain their own identity so the “Provider” can bill _them_ instead of the forwarded caller.
Besides that, Lync sends INVITE requests with a PAI containing only tel: uri, which is illegal.