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CUCM v. 9.2 how to block an incoming malicious number


The customer is receiving continuous call from an especific number. He ask me if we could block. The call is coming through a SIP trunk, how can i block??

Thanks Anna



You could set up voice translation rules on the CUBE for inbound numbers and reject them there, that's the best way to accomplish this task without going into CUCM translation patterns.  Make the voice translation rule, set it to inbound on the dial-peer it matches and you are done.


Example taken from a Blog:

!Voice Translation Rule set
voice translation-rule 69
  rule 1 reject /^800.*/
  rule 2 reject /2025551000/
  rule 3 reject /7035551000/
!Voice Translation Profile Assignment
voice translation-profile all-blacklist
  translate calling 69

Dial-peer voice "Blah" Voip

Config Here

Translation rule inbound here


Many thanks Brandon!!


But we couldn´t follow your solution becaise in our environment doesn´t exist any CUBE. Our SP has a SBC and the managment is yours.


Exist any othe posssibility in CUCM?


Thanks Anna





Well, CUCM doesn't really offer much in this respect but there are ways to get it done.  I haven't really done it before as I do everything at the IOS voice gateway to block the inbound.  You don't have a voice gateway going to the SP SBC?  They are providing everything?  You could check this link and see if it is something you would want to do:


You might be better off getting in contact with your SP and have them put a reject rule on the SBC then.


If the number is getting to the CUCM then why not pick it up with a translation pattern and just block it or route it to a dummy number or something similar. 



Hi Andrew West,

 try this, as an example:


Create a CSS: SIP-Trunk-CSS that have access to the PT: SIP-Trunk-PT.

In the SIP Trunk > Inbound Calls window > insert the SIP-TRUNK-CSS.

In Translation Pattern configuration:
 Translation Pattern: <number to be blocked>
 PT: SIP-Trunk-PT
 Block this pattern: Call Rejected <selected>
 Route Next Hop by Calling Party Number: <checked>


Hope this helps.


Many Thanks Marcelo,


But..., i think that your configuration will blocker all the incoming calls. Nowadays the sip trunk > inbound calls  has another CSS that access to system partitions.

and i have a question, in case we change this parameter force reset in SIP Trunk?







LIke I said, if the call is getting to the CUCM then just pick it up with a translation pattern and block it. 

Rising star

Callmanager 8.X and later allows an inbound call to be blocked by the calling number with a mgcp gateway.


Is the sip trunk pointed to a mgcp gateway?


Take a look at the following link.


Hope this helps,

if so, please rate.



I should have looked at Brandon's link he posted, before I added my posting.  It looks like it doing the just about the same thing and it references a sip trunk as well.




Cisco Employee

Just go through well written doc block call based on ANI on CUCM. though there ample of doc available on this forum how to block calls based in calling party number.






Br, Nadeem Please rate all useful post.

You can configure anonymous call rejection on cucm to block calls from anonymous callers at the SIP trunk using the SIP Profile page configuration settings. Select the “Reject anonymous incoming calls” checkboxes on the SIP Profile page. When the Reject anonymous incoming calls checkbox is selected, all anonymous incoming calls on the SIP trunk associated this SIP Profile will be rejected.

Please make the necessary changes to the SIP profile and make a test call after hours by dialling a number using *67 <DN> from PSTN to HCS DN and the call should be blocked.  When an anonymous call is rejected by call manager, it will send SIP error response 433 - Anonymity disallowed to the initial INVITE. CUCM will also include Q.850 Reason header with cause = 21 (Call Rejected) in 433 response.