With the increasing deployment of Cisco Communications Systems solutions, dial plans have become more complex to implement, especially in large enterprises that consist of numerous call control devices. Some examples of these call control devices are Cisco Unified Border Element, Cisco Unified SRST, Cisco Unified Communications Manager, Cisco Unified Communications Manager Express, and Cisco IOS gateways.
To simplify dial plan implementation in large deployments, it is desirable that call control devices dynamically exchange call-routing information so that any-to-any static configuration is not required. Cisco SAF allows services to be propagated through SAF-enabled network devices. Cisco CCD is the first application that uses SAF to advertise the reachability of internal directory numbers and PSTN backup numbers.
In this section, we explain how SAF works, describes its components, and show how to configure it. We also describe how CCD uses SAF to dynamically exchange call-routing information and how you can implement CCD in Cisco Unified Communications Manager and in Cisco IOS Software.