A private extension used in the Session Initiation Protocol (SIP). The P-asserted-id is a Sip header field that contains a SIP Uniform resource Identifier (URI) and an optional display name such as:

“Joe Brown” <sip:topengr@avaya.com>

A SIP proxy server can insert a P-asserted-id header into a message and forward it to another trusted proxy. However, if the user requests that this information be kept private, then the SIP proxy must remove this field prior to forwarding it to an untrusted proxy.