Proper clock synchronization is critical to ensuring good performance, improving troubleshooting, and producing accurate call detail records (CDRs) for billing. There is more than one way to synchronize time in Cisco CallManager systems and gateways. Using results of lab tests of the two primary options, Cisco IP Telephony Clock Synchronization: Best Practices compares the advantages of each, shows how to mitigate risks, and explains the need to synchronize with an external network time server (such as the Symmetricom NTP Server S100).

Want voice quality and service reliability for your VoIP? Without precise time synchronization, you can forget it. If those who approve budgets need convincing that a high quality VoIP network requires the highest quality network synchronization, read them Synchronization Essentials of VoIP and then ask if they would rather "Sync Now or Sink Later."