Cisco SRST Configuration

Published by Keyboard Banger on

Cisco SRST configuration for SCCP phones

First, check this nice Youtube link as an introduction to configuring Cisco SRST.

Configuration on the branch1 voice gateway:

cisco-srst--2016-06-11 08_32_46

I first used my VTGO phones to experiment SRST in my home lab. They did not work when the WAN failed. So I switched for an instance of Cisco IP Communicator instead.

The mini lab I used to write this post is basically composed of:

  • CUCM
  • a voice router
  • Cisco CIPC

cisco-srst--2016-04-03 19_13_16

In normal situation, I mean when the WAN link is up, the phone is registered to CUCM:

cisco-srst--2016-04-03 19_44_31

I configured the voice router for SRST. Pay attention that configuring CUCME as SRST is another thing.

In my home lab, I configured the voice router with SRST (see the Youtube link I provided above). Then I configured the emulated PSTN as a CUBE. I added the four possible “allow-connections” statements.

cisco-srst-configuration-2016-04-04 18_28_04

I make sure the Emulated-PSTN router is configured as CUBE properly:

cisco-srst-configuration-2016-04-04 18_29_07

I configure an appropriate dial peer for PSTN connectivity to HQ. I configured a dial peer on BR1 router to be used when the phone is in SRST mode. This dial peer matches calls to HQ DID numbers, and routes on the Emulated PSTN.

cisco-srst-configuration-2016-04-04 18_29_53

I shut down the WAN interface on branch 1:

cisco-srst-configuration-2016-04-04 18_30_45

The phone at branch 1 gets registered to the local router in SRST:

cisco-srst-configuration-2016-04-04 18_31_34

The CIPC phone displays a meaningful message:

cisco-srst--2016-04-03 19_17_02

I make a call from branch 1 to the full PSTN number of the HQ:

cisco-srst--2016-04-03 19_17_25

When the call goes from Branch 1 to the PSTN link, the call leg matches dial peer 111 on PSTN router. Then the outbound call leg matches dial peer 1717:

cisco-srst-configuration-2016-04-04 18_32_57

I still have to properly format the calling number (from branch1) to be displayed correctly on HQ phones. I could do that with voice translation rules and profiles:

cisco-srst--2016-04-03 19_17_55

Categories: CCNP Collaboration

Keyboard Banger

Keyboard Banger is a network engineer from Africa. He has been working in network support and administration since 2008. He started writing study notes about certification exams and technology topics a couple of years ago. When he's not writing articles, he can be found wandering on technical forums.


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