External PSTN Call Blocking

Unanswered Question
Aug 7th, 2008

With Unified Communications Manger 4.1.3sr5d is it possible to block specific incoming PSTN callers based on their callerid-number?

I have this problem too.
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Ayodeji oladipo... Thu, 08/07/2008 - 04:46


You can use a combination of call-block and xlation profile to achive this..example below:

Here I am blocking all incoming calls beginning with 202456...

voice translation-rule 1

rule 1 reject \^2024561212\

voice translation-profile block

translate calling 1

Router(config)# dial-peer voice 5 pots

Router(config-dial-peer)# call-block translation-profile incoming block

Router(config-dial-peer)# call-block disconnect-cause incoming invalid-number

From this excellent doc..


Ayodeji oladipo... Thu, 08/07/2008 - 04:54


Because the xlation profile is applied at your POTS ports, which is where the call hits first before it goes to callmanager

zhangjianping Thu, 08/07/2008 - 04:59

It's great under H323, whereas I don't think the translation profile can work under MGCP.

It seems it doesn't work under MGCP

Michael Owuor Thu, 08/07/2008 - 05:13

Thats true, Zhang. With MGCP, the dial plan intelligence resides on the CUCM, so any configuration on the gateway is ignored. There's no easy way to do this when the gateway is MGCP controlled.



Michael Owuor Thu, 08/07/2008 - 07:08

Hi Zhang,

This tech note on CCO states it can't be done, and recommends using H.323 and then using translation rules like Deji described earlier:


I've seen suggestions of using CRS to accomplish the goal. Your CRS script can be coded to inspect the ANI of all incoming calls, and then route the call based on whether the ANI matches a given string. This would work, but the obvious downside here is the added layer of complexity, and the overhead of routing all incoming calls through CRS. If you are not already CRS, this is also an expensive solution.

Hope this helps.



TODD BERGMAN Thu, 08/07/2008 - 07:12

Thanks for the responses. Yes I kind of thought MGCP would not work that is why I asked.

We are using IPCC currently for all call flows so I will give that work around a try.

Thanks all...

Michael Owuor Thu, 08/07/2008 - 07:23

You're welcome Todd. Let us know how it works out for you.

Happy Thursday!



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