Central Site Remote Access Switch 17Call Restrictions 372Configuring Call Restrictions 372Call Restriction Configuration Elements 373Call Restrictions Background Information 376Bandwidth Reservation 376Configuring Bandwidth Reservation 376Bandwidth Reservation Configuration Elements 378Bandwidth Reservation Background Information 379Semipermanent Connections 379Configuring Semipermanent Connections 379Semipermanent Connections Configuration Elements 381Semipermanent Connections Background Information 381Interactions with Other Features 381CSM as a Call Control Manager 383Configuring CSM for Call Control 383Configuration Elements 383Background Information 384Call Control Management 384Limitations/Considerations 385D Channel Callback 385Configuring D Channel Callback 385D Channel Callback Configuration Elements 386D Channel Callback Background Information 386Digital Modem Inactivity Timeout 387Configuring the Digital Modem Inactivity Timeout 387Modem Inactivity Timeout Configuration Elements 387Modem Inactivity Timeout Background Information 388Configuring Other Advanced Options 389Overview 389The Digital Modem 389Configuring for a Digital Modem 389Digital Modem Background Information 390Supported Modes of Connection 391Relationships between Digital Modem and other Features 392Default Async Protocol 392PPP Mode 392Terminal Mode 393Call Disconnect 393Default Async Protocol Configuration Elements 393Background Information 394Autosense Feature 395Limitations 395Interactions with Other Features 395PPP Configuration 396Configuring PPP 396PPP Configuration Elements 396PPP Background Information 398PPP Link Failure Detection 398PPP Reference Documents 399