An embodiment provides a user equipment that includes a processor configured to receive a Session Initiation Protocol (SIP) NOTIFY message transmitted by a network component as a result of a registration event. The SIP NOTIFY message contains at least a portion of information included in a first SIP message sent between a first user equipment and the network component. Another embodiment provides method and apparatus for a network node to determine whether filter criteria include one or more indicators that specify the need for information, and including in a second SIP message the information specified by the one or more indicators.