Lync RGS and sim-ring

Here is why Lync does not support simulataneous rng on responce groups:

http://blogs.technet.com/b/nexthop/archive/2010/10/27/simultaneous-ringing-disabled-for-response-group-service-calls-in-office-communications-server-2007-r2.aspx

You can overrride this by an app or MSPL script - check out this site for more info http://blog.greenl.ee/category/mspl/