Deployments of voice over IP (VoIP) networks continue at a rapid pace. Voice gateways are an essential part of VoIP networks, handling the many tasks involved in translating between transmission formats and protocols and acting as the interface between an IP telephony network and the PSTN or PBX. Gatekeepers and IP-to-IP gateways help these networks scale. Gatekeepers provide call admission control, call routing, address resolution, and bandwidth management between H.323 endpoints including Cisco IOS voice gateways and Cisco Unified CallManager clusters. IP-to-IP gateways allow VoIP calls to traverse disparate IP networks.

Cisco Voice Gateways and Gatekeepers provides detailed solutions to real-world problems encountered when implementing a VoIP network. This practical guide helps you understand Cisco gateways and gatekeepers and configure them properly. Gateway selection, design issues, feature configuration, and security and high-availability issues are all covered in depth. The abundant examples, screen shots, configuration snips, and case studies make this a truly practical and useful guide for anyone interested in the proper implementation of gateways and gatekeepers in a VoIP network. Emphasis is placed on the accepted best practices and common issues encountered in real-world deployments.

Cisco Voice Gateways and Gatekeepers is divided into four parts. Part I provides an overview of an IP voice network. Part II is dedicated to voice gateways, including discussions of Media Gateway Control Protocol (MGCP); H.323; Session Initiation Protocol (SIP); voice circuit options; connecting to the PSTN, PBX, and IP WAN; dial plans; digit manipulation; route selection; class of restriction; Survivable Remote Site Telephony (SRST) and MGCP fallback; digital signal processor (DSP) resources; and Tool Command Languaue (Tcl) scripts and Voice XML (VXML). Part III addresses voice gatekeepers, including detailed deployment and configuration. Part IV is dedicated to IP-to-IP gateways.

• Understand the pros and cons of MGCP, H.323, and SIP, how they implement call signaling and describe call flow, and how to configure each protocol
• Learn the various analog and digital voice circuit options used to connect a VoIP network to the PSTN
• Configure and troubleshoot PSTN, PBX, and IP WAN connections
• Build scalable dial plans and understand the different types of dial peers
• Understand the various ways gateways control called and calling phone numbers
• Examine call admission control (CAC) techniques
• Configure Class of Restrictions (CoR) for both inbound and outbound calls
• Deploy and troubleshoot SRST and MGCP fallback
• Evaluate DSP considerations and resources
• Support interactive voice response (IVR) and advanced call-handing applications using Tcl scripts and VXML
• Deploy and configure basic and advanced gatekeeper functions
• Configure and troubleshoot IP-to-IP gateways

This book is also recommended self-study training for the CCVP GWGK exam.

This IP communications book is part of the Cisco Press Networking Technology Series. IP communications titles from Cisco Press help networking professionals understand voice and IP telephony technologies, plan and design converged networks, and implement network solutions for increased productivity.