538 CHAPTER 20 Exchange 2010 and SharePoint 2010 Integration TABLE 20.2 Supported IP/VoIP Gateways for Exchange 2010 UM Manufacturer Net Nortel Quintum Model VX1200 CS1000 Tenor-series Supported Protocols -T1/ or E1 with CAS--In-Band or SMDI, T1/E1 with Primary Rate Interface (PRI) and Q.SIG or Direct SIP Analog PSTN To support Exchange Server 2010 unified messaging, one or both types of IP/VoIP device configurations are used when connecting a telephony network infrastructure to a data network infrastructure. All these solutions must communicate with the unified messenger through SIP over TCP (TLS encrypted) and SRTP. Unified Messaging Protocols The Exchange 2010 Unified Messaging servers use several telephony-related protocols to integrate and communicate with telephony devices. These protocols are listed and discussed in the following list: