Table of Contents

Issue


User will get warning message on Dial-in Conferencing page.
Error Message: Your phone extension is not configured. Use your complete phone number and PIN to join conferences.

Problem Statement
Error message itself states that extension is not configured. You need to configure your extension number. There are two ways to add extension; one is through Lync Server Control Panel and second using Lync Management Shell.
Turns out that you need to add the extension details to your Tel URI number in OCS/ Lync. This is done by adding “; ext=xxxx” after your Tel URI. i.e.: tel: +12345678900 ;ext=8900 (we are obviously using a 4-digit extension internally).

Resolution
Format:    TEL:+12345678900;ext=8900

Option 1

1.     Log on to Server and open ‘Lync Server Control Panel’.

2.     Click on ‘Users’ and search affected user ‘Ilag Balu’

3.     In Line URL :

a.     Tel:+12345678900;ext=8900

     In Line URL :

a.     4.     Click on ‘Commit’. Ref below image 

Option 2
Open Lync Management Shell.
Set-CsUser –Identity “Ilag, Balu” –LineURI “tel:+12345678900;tex=8900”
Once completed I know get my extension listed after reconnecting to the dial-in conferencing settings.
If you are connecting to a conference call over your office phone or  mobile etc. that instead of having to enter your entire phone number as an identifier, you can simply use your extension number.