Book excerpt: As a final exam preparation tool, the CCNP Voice TVoice 642-427 Quick Reference provides a concise review of all objectives on the new CCNP Voice Troubleshooting Cisco Unified Communications exam (642-427). This eBook provides you with detailed, graphical-based information, highlighting only the key topics in cram-style format. With this document as your guide, you will review topics on troubleshooting Cisco Unified Communications systems and solutions in different deployments. In addition, this eBook covers troubleshooting methodology, triage, resources, tools, and fixes for Cisco Unified Communications Manager and the new v8.0 features such as Call Control Discovery, SIP Precondition, and Extension Mobility Cross Cluster, as well as dial plan troubleshooting including globalized call routing. This fact-filled Quick Reference allows you to get all-important information at a glance, helping you to focus your study on areas of weakness and to enhance memory retention of essential exam concepts.