SRST and four digit dialing

[jgorniak]

My customer has two locations, site A and Site B connected together by a 10MB Ethernet connection, with Site A having CallMgr 4.0.

Both sites have a PRI terminated into 2811 routers for incoming/outgoing calls.

Customer can do 4 digit dialing between sites when the WAN or Ethernet connection is up.

Now the customer wants to have users at Site B which has a 2811 with SRST configuring to continue to do 4 digit dialing to site A when the WAN or Ethernet connection drops. Can or how do I configure this for SRST?

The callmgr handles the 4 digit dialing today, but what happens when Site B goes into SRST mode?

We have tested SRST at Site B and we can dial out 7 or 10 digits using the PRI, but not 4 digits.

Any help would be greatful....

[dgahm]

In SRST mode the phones register with the router as H323 peers so may be able to use number expansion to provide this functionality. This would mean you will have to define POTS dial peers pointing to your PRIs instead of using the access code fallback config. These peers would send the full 7 or 10 digits to the carrier.

http://www.cisco.com/en/US/customer/products/sw/iosswrel/ps1835/products_configuration_guide_chapter09186a0080080aec.html#wp1244664

You can define an extension number as the destination pattern for a dial peer. The router can be configured to recognize the extension number and expand it into its full E.164 dialed number when the num-exp global configuration command is used with the destination-pattern dial-peer configuration command.

Number expansion is a globally applied rule that enables you to define a set of digits for the router to prepend to the beginning of a dialed string before passing it to the remote telephony device. This reduces the number of digits that a user must dial to reach a remote location. Number expansion is similar to using a prefix, except that number expansion is applied globally to all dial peers.