V7122 Gateway User Guide 7Fax & Modem Transport Modes 250Fax/Modem Settings 250Event Notification using X-Detect Header 252ThroughPacket™ 254Dynamic Jitter Buffer Operation 254Configuring the Gateway’s Alternative Routing (based on Connectivity and QoS) 256Alternative Routing Mechanism 256Determining the Availability of Destination IP Addresses 256PSTN Fallback as a Special Case of Alternative Routing 257Relevant Parameters 257Call Detail Report 257Supported RADIUS Attributes 259RADIUS Server Messages 261Trunk to Trunk Routing Example 261Proxy or Registrar Registration Example 262SIP Call Flow Example 263SIP Authentication Example 266Reader’s Notes 270C HAPTER 9: N ETWORKING C APABILITIES 271Ethernet Interface Configuration 271Ethernet Interface Redundancy 272NAT (Network Address Translation) Support 272STUN 273First Incoming Packet Mechanism 274No-Op Packets 275Point-to-Point Protocol over Ethernet (PPPoE) 275Point-to-Point Protocol (PPP) Overview 275PPPoE Overview 276PPPoE in 3Com Gateways 277IP Multicasting 278Robust Reception of RTP Streams 278Multiple Routers Support 278Simple Network Time Protocol Support 279IP QoS Using Differentiated Services (DiffServ) 279VLANS and Multiple IPs 280Multiple IPs 280
