Overview of the IMSG

This chapter describes the Integrated Multi-Service Gateway (IMSG). Topics include:

• IMSG Session Border Control Solution Overview
• Supported Hardware Platforms for the IMSG
• IMSG Architecture Overview
• BSG Policy Overview
• Policy Configuration Limits
• Manipulation of Headers and Request URIs in SIP Messages
• Media Anchoring Overview
• SIP Routing Overview
• SIP Routing with Server Clusters Overview
• Locating SIP Servers Using DNS Overview
• Virtual Interfaces and NAT Pool Assignment with the IMSG
• IMSG VPN Routing Overview
• SIP Timers Overview
• Providing Redirection for Messages with 3XX Responses Overview
• Providing QoS for VoIP Traffic Overview
• IMSG Overload Protection Overview
• Providing Call Admission Control Overview