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PSTN Redundancy

Category:Cisco Systems -> Voice

PSTN redundancy example diagram:

PSTN-Redundancy-10.png

The primary voice communication channel is IP WAN. In case of main link outage the backup PSTN line used.

Tyumen(config)# dial-peer voice 10 voip
Tyumen(config-dial-peer)# destination-pattern 5...
Tyumen(config-dial-peer)# session target ipv4:10.0.0.2
Tyumen(config-dial-peer)# preference 0
Tyumen(config-dial-peer)# exit
Tyumen(config)# dial-peer voice 11 pots
Tyumen(config-dial-peer)# destination-pattern 5...
Tyumen(config-dial-peer)# port 0/0/0:15
Tyumen(config-dial-peer)# preference 1
Tyumen(config-dial-peer)# no digit-strip
Tyumen(config-dial-peer)# prefix 8495777777

Moscow(config)# dial-peer voice 10 voip
Moscow(config-dial-peer)# destination-pattern 4...
Moscow(config-dial-peer)# session target ipv4:10.0.0.1
Moscow(config-dial-peer)# preference 0
Moscow(config-dial-peer)# exit
Moscow(config)# dial-peer voice 11 pots
Moscow(config-dial-peer)# destination-pattern 4...
Moscow(config-dial-peer)# port 0/0/0:15
Moscow(config-dial-peer)# preference 1
Moscow(config-dial-peer)# no digit-strip
Moscow(config-dial-peer)# prefix 83452555555 

The lower preference value the higer the priority of the channel.
no digit-strip is used on other than FXO, E1, T1, etc. interfaces. This command prevents the prefix from stripping while sending the dialed digits to the carrier.

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