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New Member

Direct dial extension from outside

Please refer the drawing. We got a SIP trunk from service provider and connected to existing CCM. Assume there are 5 telephone extensions connected to CCM starting from 1001-1005. Only 2 direct numbers provided with the SIP trunk. My ultimate requirement is to dial specific extension directly from outside. There are no enough direct numbers to map with each extension.  Also I want to program external phones to be configured with speed dial facility to dial internal extension by pressing one button. Up to my knowledge the solution should be somewhat like this, the speed dial entry should carry the direct number to reach call manager (0117123456 or 7) followed by the extension (1001). Anyhow PSTN network terminate this call at CCM and after that it should trigger extension sent (1001). Really appreciate if someone can help me to sort this matter out

thank you

New Member

Re: Direct dial extension from outside

It really depends on what size DID block do you have. For example in this case, if you have a range of 5 DID numbers, then your extensions can be called directly from outside, however in this case you only shown 2 in the diagram, meaning only two phones can be mapped using translation patterns. Your second solution can be an AutoAttendant type of setup using Unity or Unity Connection, where your call comes to the main number, and then extensions can be dialed after the greeting is played to ring that extension.

As for the speed dial, that's easy, you can configure that on a speed dial button.

If this post helped you, please rate.


VIP Super Bronze

Re: Direct dial extension from outside

In addition to techguy73's reply, I want to point out there are a few design issues with what you are proposing:

  1. CUCM is not intended to terminate a PSTN-facing SIP trunk. This is a function typically assigned to a CUBE. This was discussed and the reasons weighed on this thread:
  2. If you only have five directory numbers [users] a CUCM installation is almost certainly overkill. I suggest you look at a CME installation instead. This also works out better for the SIP trunk since they can coexist on the same ISR.
    Please remember to rate helpful responses and identify helpful or