Books:

     Cisco CallManager Best Practices

     Troubleshooting Cisco IP Telephony

     Configuring CallManager and Unity: A Step-by-Step Guide

     Cisco IP Communications Express: CallManager Express with Cisco Unity Express

     Cisco CallManager Fundamentals

     Integrating Voice and Data Networks

URLS:

Design Tools & References:

     SRND guides

     Cisco Power Calculator

     Cisco DSP Calculator

     Cisco Codec Calculator

     SAFE Security Guides

     Traffic Analysis for Voice over IP (Erlang Models Explained)

T1 CAS Signaling:

     Understanding How Digital T1 CAS (Robbed Bit Signaling) Works in IOS Gateways

     Configuring and Troubleshooting T1 CAS Signaling

     Implementing T1 CAS

     Configuring MGCP CAS MD Package

T1 NFAS

     Configuring NFAS with Four T1s

E1 R2 Signaling:

     E1 R2 Signaling Configuration and Troubleshooting

     E1 R2 Signaling Theory

Number Translations:

     Number Translation using Voice Translation Profiles

NM-HDA

     Understanding High-Density Analog Voice/Fax Network Modules (NM-HDA)

     IP Communications High Density Analog Voice\Fax Network Modules

CMM

     Cisco Catalyst 6500 and Cisco 7600 Series Communication Media Module Features

     Communication Media Module IP Connectivity 

EVM-HD

     Cisco High Density Analog and Digital Extension Module for Voice and Fax

H323

     H.323 Overview

     H.323 Technology Home

     Cisco IOS H.323 Gateway Configuration for Use with Cisco CallManager

     Cisco IOS H.323 Configuration Guide

     Troubleshooting No Ringback Tone on ISDN-VoIP (H.323) Calls

     Troubleshooting No Busy Tone and No Announcement Messages H323 Calls

MGCP    

     MGCP VoIP Call Admission Control

     Configuring MGCP-Controlled Backhaul of BRI Signaling in with Unified CallManager

     Configuring Tone Download to MGCP Gateways

     Configuring MGCP PRI Backhaul and T1 CAS Support for Cisco Unified CallManager

     Busy-Out ISDN B-Channels in Cisco CallManager Configuration Example

SIP

     SIP: Measurement-Based Call Admission Control for SIP

ISDN

     Troubleshooting ISDN BRI Layer 3 Using the debug isdn q931 Command

     Understanding debug isdn q931 Disconnect Cause Codes

TCL Scripting

     Configuring Basic Functionality for Tcl and VoiceXML Applications

     Tcl scripts that can be downloaded from Cisco.com

     Cisco IOS Tcl IVR and VoiceXML Application Guide - 12.3(14)T and later

     TCL IVR API Version 2.0 Programming Guide

     Cisco VoiceXML Programmer's Guide

     Cisco IOS Scripting with Tcl

DSP Farms

     Cisco DSP Calculator

     CallManager and IOS Gateway DSP Farm Configuration Example

     High-Density Packet Voice Digital Signal Processor Modules (Details & pictures)

     Cisco Enhanced Conferencing and Transcoding for Voice Gateway Routers

     Understanding Codecs: Complexity, Hardware Support, MOS, and Negotiation

IP-IP Gateway    

     Fundamental Cisco Multiservice IP-to-IP Gateway Configuration

     Cisco Multiservice IP-to-IP Gateway with Gatekeeper

Gatekeeper

     VoIP with Gatekeeper

     Understanding H.323 Gatekeepers

     Understanding Cisco IOS Gatekeeper Call Routing

     Troubleshooting Gatekeeper Registration Issues

     Troubleshooting GUP, Alternate Endpoint and Load Balancing

     Cisco High-Performance Gatekeeper

     Cisco Multiservice IP-to-IP Gateway

     Cisco Multiservice IP-to-IP Gateway with Gatekeeper

Analog Interfaces

     Understanding E&M Voice Interface Cards

     Understanding Foreign Exchange Station (FXS) Voice Interface Cards

     Analog DID on FXS ports 

     Understanding FXO Disconnect Problem (VIC-2DID)

     Analog Signaling (E & M, DID, FXS, FXO)

     Understanding Why Telephones in the United Kingdom Connected to Cisco FXS Interfaces May Fail to Ring

     Inability To Break Dialtone in a Voice over IP Network

Q.SIG

     Siemens QSIG Interoperability: Calling Name and Call Forward Do Not Work 

Interoperability

      Cisco Interoperability Portal

      Cisco CallManager and Cisco IOS Interoperability Guide

      Cisco Voice Gateway Router Interoperability with CallManager
 

Faxing

     T.37 = Unity IP Fax Outbound Gateway Configuration Example

     T.37 = Unity IP Fax Inbound Gateway Configuration Example

     Configuring T.37 Store and Forward Fax

    Cisco Fax Services over IP Application Guide

Modems

     Modem Support for VoIP

SAA

     Cisco Unified Operations Manager

     Cisco Unified Operations Manager Home