Most RecentMost ViewedMost LikesDirect SIP: Configuring Mediation ServerFirst published on TECHNET on Jun 13, 2010 This article is a partner article to "Direct SIP: Cisco Unified Communications Manager 6.SIP Trunking: What Is It? Why Do I Need It? How Do I Deploy It?First published on TECHNET on Jun 13, 2010 A SIP trunk is a direct connection between your organization and an ITSP.