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In Lync 2013 Enterprise users is allowed to make PSTN dial out from a Lync conference without a plus CAL license.

This feature is controlled, in the Conference Policy for the user

When a user is in a conference, the user has the possibility to dial out to invite others by phone.

This works great, however since the it’s only a Enterprise CAL users he/she don’t have a lineuri number, the conference will make a PSTN call though the mediation server without a phone number.

It is then up to the VoIP gateway or sip trunk to provide a number. If using a sip trunk provider I have experienced three different outcomes of this:

  1. The call is blocked because the sip trunk provider authenticates though the sip trunk number which is not sent in the INVITE:
  2. The call is shown as “Unknown” or “Private”
  3. The call is shown as the default number for the sip trunk provider.

So how can you control which number you present:

Easy…. Give the user an internal number and manipulate the number at the gateway:


So first, you will give the Enterprise CAL user a LineUri number, which must be do from powershell with this cmdlet:

Set-csUser ‘sip:John.Doe@Exchangepro.dk’ -LineUri tel:+4610002


Next you give the user a conference policy which gives the user access to make PSTN dial out:

Grant-CsConferencingPolicy ‘sip:John.Doe@Exchangepro.dk ‘ -PolicyName ‘DialOut-Conference-Policy’


Next you give the user a dialplan (in the dialplan you can control the Normalization rules, so the users don’t need to dial an E.164 phone number like +4512345678 but instead can dial 12345678.)

Grant-CsDialPlan ‘sip:John.Doe@Exchangepro.dk ‘ -PolicyName ‘Dialout-Dialplan’


Next you give the user a Voice Policy which is bound to a PSTN Usage which again is bound to a Route.

Grant-CsVoicePolicy ‘sip:John.Doe@Exchangepro.dk ‘ -PolicyName ‘Dialout-Voicepolicy’


So fare, so good. The last thing that you will do is to manipulate the users number on the trunk to a number that you want to show (a number you own).

In my case I choose to show the Dialin Conference Number for my solution:


On the Trunk Configuration, you edit your configuration – Scroll down to “Calling number translation rules” and create a new one:

So what this translation rule looks for is a number that is Exactly 8 digits long and starts with +461 then a number in range 0-9 and 0-9 and 0-9 and 0-9

(the rule works for numbers in the range +4610000 – +4619999)

It then replaces the 8 digits with my conference number.


That’s how easy it is.









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