How to enable Team-Call Group:
1. Once logged into the primary Lync client, click on the Gear Box in the top right hand corner.
2. On the box that appears, click on Call Forwarding, then Edit my team-call group members.
3. On the box that appears, click Add and enter the usernames of all the Microsoft Lync users in your organization you want in your team-call group one at a time, then click OK.
4. You will receive a message informing you to select Simultaneously Ring. On the previous screen, select Simultaneously ring and drop down to My Team-Call Group and click OK.