H.323 Dial-Peer Configuration Best Practices
To illustrate best practice procedures when configuring H.323 dial peers on a Cisco IOS
router, consider Figure 7-22 and the corresponding dial-peer configuration shown in
Example 7-20. In the example, dial-peer 1 is used to route calls according to their DNIS,
and dial peers 100 and 101 are used to route calls to the primary UCM server, unless it
has lost connectivity, and then to use the backup, or secondary, UCM server.
Chapter 7: Configuring Advanced Dial Plans 405
V
PSTN
Router
UCM-1
10.10.10.2
UCM-2
10.10.10.3
Figure 7-22 Dial-Peer Best Practice Sample Topology
Example 7-20 Best Practice Dial-Peer Configuration
Router(config)#dial-peer voice 1 pots
Router(config-dial-peer)#incoming called-number .
Router(config-dial-peer)#direct-inward-dial
Router(config-dial-peer)#exit
Router(config)#dial-peer voice 100 voip
Example 7-20 Best Practice Dial-Peer Configuration continued
Router(config-dial-peer)#preference 1
Router(config-dial-peer)#destination-pattern 1...
Router(config-dial-peer)#session target ipv4:10.10.10.2
Router(config-dial-peer)#exit
Router(config)#dial-peer voice 101 voip
Router(config-dial-peer)#preference 2
Router(config-dial-peer)#destination-pattern 1...
Router(config-dial-peer)#session target ipv4:10.10.10.3
The previous figure and example illustrate the following best practice procedures:
■ To ensure that incoming PSTN calls are directly routed to their destination based on
the DNIS information, create a default POTS dial peer with the direct-inward-dial
attribute.
406 Authorized Self-Study Guide Cisco Voice over IP (CVOICE)
Example 7-20 Best Practice Dial-Peer Configuration continued
Router(config-dial-peer)#preference 1
Router(config-dial-peer)#destination-pattern 1...
Router(config-dial-peer)#session target ipv4:10.10.10.2
Router(config-dial-peer)#exit
Router(config)#dial-peer voice 101 voip
Router(config-dial-peer)#preference 2
Router(config-dial-peer)#destination-pattern 1...
Router(config-dial-peer)#session target ipv4:10.10.10.3
Note This should be the first POTS dial peer that you configure on the gateway. It
should be the only dial peer that contains a “.” for the destination pattern and direct
inward dial. It should not contain a port number.
■ When using the router as an H.323 gateway connected to a Cisco UCM cluster, provide
redundancy by configuring at least two VoIP dial peers with the same destination
pattern pointing to two different UCM servers. Use the preference attribute to
select the priority order between primary and secondary UCM servers.