PSTN calls in SRST mode

fgasimzade · ‎09-06-2009

I can not make my IP phones to call through PSTN in SRST mode.

My SRST router is configured with a SIP trunk to our Call Manager. The problem is that when WAN link fails, router still tries to send all calls through SIP trunk, ignoring other configured dial peers.

dial-peer voice 1 pots

destination-pattern 0.......

port 0/1/0

forward-digits 7

!

dial-peer voice 2 pots

service mgcpapp

shutdown

destination-pattern 00.........

port 0/1/0

!

dial-peer voice 3 voip

destination-pattern ....

session protocol sipv2

session target ipv4:192.168.16.6

dtmf-relay rtp-nte

codec g711ulaw

no vad

!

dial-peer voice 4 pots

service mgcpapp

shutdown

destination-pattern 0T

port 0/1/0

!

As you can see from my config, when I dial 04374757 in SRST mode, router rips off 4757 and tries to call 0437 through dial-peer voice 3 instead of dial-peer voice 1. Dont know what to do with it.

Thank you in advance

pcameron · ‎09-07-2009

It's working exactly as you have configured things. Your dial peer 3 has a destination pattern of '....' so it will match on ANY 4 digits. The destination pattern on dial peer 1 will be expecting 0 with 7 more digits, so after any 4 digits the call will be sent via the SIP dial peer.

You should always make the destination pattern on your dial peers to be as specific as possible to get around these dial plan overlaps. If possible use something like 'destination-pattern [1-9]...' on dial peer 3 to exclude the leading 0 access code for the POTS dial peer.