Hello!

We are deploying custom PSTN service and we've faced with this issue:

When user is configured for telephony in Lync and does outgoing call Lync server puts his Line URI in "from" field during SIP interaction. So PSTN sees that call is came from +155512343;ext=111. I understand that this is default behavior but is it possible to force Lync to set SIP address as "from" field? At this moment our PSTN knows only SIP addresses (like user1@mylyncdomain.com) and it should identify them.

Thanks!

Ilya.

• Edited by Ilya Girman Thursday, January 23, 2014 5:00 PM

If you are passing a call to the PSTN it needs to know the calling number as the traditional telephone network does not know what a SIP address is. You can use a route to block or hide a users number behind say the pilot/office number, however it has to be a number rather than a SIP address.

Why do you want to pass a SIP address rather than a number? 

Because we don't want to configure our pstn with phone numbers for user's authorization. SIP address is more handy.

Actually I've found some workaround. I've just removed Line URI (set to blank) in user's properties in Lync server after phone successful sing-in with extension and pin. After that telephone begins to show sip address on its screen and sends it in SIP requests.

Nice, great that you found a solution :)