SRST Questions

Answered Question
Jul 18th, 2008


Couple of questions regards srst.

Call Manager 6.1.2

SRST Router - 2821 12.4.15T5

7941 Phones

1. This is a h323 gateway. Do i need the mgcp commands?

2. I can only make 4 digit calls to local srst phones. How do i make external calls out to the pstn via an E1 interface?

3.Do i need a secondary dialtone?

4.A Default dial-peer has a dest pattern of 1 but when trying to call 1xxxxxxx numbers from a srst phone. 1 is the only number presented to the pstn.

5. Is this command required for non mgcp gateways - isdn bind-l3 ccm-manager ??

Any help much appreciated...


I have this problem too.
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Correct Answer by Ayodeji oladipo... about 8 years 6 months ago


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Overall Rating: 4.5 (2 ratings)
Ayodeji oladipo... Fri, 07/18/2008 - 03:01


Hope you are well..

Asnwesr below:

1. NO. H.323 and mgcp are two different protocols. The required commands to ocnfugre each is different, hence for an h.323 gateway you do not need mgcp commands

2. When your phones are in srst mode, for them to be able to call out you need to define dial-peers similar to your route patterns in callmanager..

eg examples below

dial-peer voice 123 pots !--- For incoming DID calls

incoming called-number .


port 1/0:23


dial-peer voice 911 pots

destination-pattern 911

port 1/0:23

forward-digits 3


dial-peer voice 9911 pots

destination-pattern 9911

port 1/0:23

forward-digits 3


dial-peer voice 7 pots

destination-pattern 9[2-9]......

port 1/0:23

forward-digits 7

For more o how to setup srst see this guide..

3. No you dont.

4. Alwats avoid using default dial-peers. Define your specific dial-peers

5. NO! This command is used to backhaul mgcp layer 3 signalling fromt he gaetway back to callmanager. It is only used for MGCP gateways

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clougher01 Fri, 07/18/2008 - 20:22

Great thanks for that.

So does it mean that the reason we couldnt call any numbers other than local srst phones was that we didnt have dial-peers enabled for the correct destination-patterns?


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