The SBC Core supports caller privacy dynamically based on privacy header.
The special URI anonymous@host; user=phone in From header field denotes an anonymous user whose presentation is restricted. Microsoft Lync 2010 Mediation Server uses the alias name of user in the FROM header (instead of phone number) and without user=phone parameter, to hide a phone number. The SBC identifies these two cases as presentation restriction. When presentation is restricted, if the SIP trunk has a default number configured, the SBC uses that number in user part of FROM header while sending the egress message.
The SBC Core supports caller privacy for incoming and outgoing calls as described below: