Aastra Telecom 53I - Manual (Page 107)

Sylantro Interoperability Features
RN-001029-00, Rev 03, Release 2.1 101
5i Series IP Phone Release Notes
SIP Asserted Identity for Sylantro Servers
This release includes support for a private extension to the SIP, Asserted Identity
within Trusted Networks (as defined in RFC 3325), inside the User Agent Server
(UA) in the Aastra IP phones.
This feature allows a network of trusted SIP servers to assert the identity of
authenticated users, and verify that phone messages originate from a Trusted
Identity. Upon receiving a message from a caller in the Trust Network, the IP
phone reads the contents of the P-Asserted-Identity (PAI) header field and
displays it on the phone UI. This field contains a more accurate description of the
caller identity (extension/phone number) than is contained in the SIP message.
When an IP phone receives an incoming call, the IP phone does the following
actions:
• Checks to see if the incoming call is from a registered proxy server.
• If the call is forwarded via a registered proxy server, then the message has
already been verified and authenticated by the server. The caller is part of the
Trust Network. The IP phone UI displays the caller information contained in
the PAI header.
• If the call is not forwarded via a registered proxy server - and therefore is not
a “Trusted Entity” - the IP phone UI does not display any trust information
contained in the PAI header.