route distinguisher(An address qualifer used only within a single Internet service provider's multi-protocol label switching (MPLS) network. It is used to distinguish the distinct virtual private network (VPN) routes of separate customers who connect to the provider)
voice route(A route that contains instructions that tell Lync Server how to route calls from Enterprise Voice users to phone numbers on the public switched telephone network (PSTN), or a private branch exchange (PBX))