s a Fax Method for SIP Trunks Fax Pass-Through as a Fax Method for SIP Trunks Modem Traffic 155 Encryption Interworking Summary 158 Further Reading Chapter 9 Questions to Ask of a Service Provider Offering and an SBC Vendor Technical Requirements Session Management Signaling/Media Protocol Operational Modes Support SIP Features SIP Methods IETF and General SIP Support xiv SIP Trunking Session Timers Quality of Service Interworking Support Codecs Support SIP to H.323 Interworking Support Other Interworking Support Demarcation Topology Hiding NAT Traversal Session Routing Accounting and Billing Security 173 Privacy 173 Firewall Integration Threat Protection Policy 174 Access Control Operations and Management Event/Alarm Management Configuration Management Performance Management Security Management Fault Management Other Questions about Operations and Management System Specification Performance/Sizing Availability Load Balancing Performance Delivery, Documentation, and Support Delivery 181 Documentation and Training Support Quality 183 Quality Assurance Certification Business Bidder Background Bidder References Cost 188 Summary Further Reading Part III: Deploying SIP Trunks Chapter 10 Deployment Scenarios Enterprise SIP Trunk for PSTN Access Cisco UCM SIP to an AT&T FlexReach SIP Trunk CUCM to a Verizon SIP Trunk Cisco UCM H.323 Interconnect Sharing a SIP Trunk Across the Enterprise Contact Center SIP Trunk Interconnect SMB SIP Trunk for PSTN Access Additional Deployment Variations CUBE with SRST CUBE Transcoding CUBE with Integrated Cisco IOS Firewall CUBE with Tcl Scripting CUBE Using SIP TLS to CUCM 232 Telepresence Business-to-Business Interconnect Miscellaneous Helpful Configurations Collocated MTP SIP IP Address Bind SIP Out-of-Dialog OPTIONS Ping Multiple Codecs Outbound from CUCM on a SIP Trunk 237 SIP Header Manipulation Dual Digit Drop SIP Registration SIP Transport Choices QoS Remarking SIP User Agent Parameters Troubleshooting Summary Further Reading 241 xvi SIP Trunking Chapter 11 Deployment Steps and B