Inter-Trunk Routing

In previous versions of Lync Server 2010, all calls had to either start with or terminate on a Lync endpoint. There was no way to route calls through Lync Server between two IP PBXs or gateways. Inter-trunk routing in Lync Server 2013 allows for this scenario to take place, which might help organizations gradually move users to Enterprise Voice. Lync Server 2013 can be deployed as shown in Figure 2.7, such that it is “in front of” an existing PBX, and owns the core routing logic that allows calls to still reach users on a legacy PBX, or even allows calling between two existing PBX systems.

Figure 2.7. Inter-trunk routing.

Call control is achieved by assigning PSTN Usage objects directly to a trunk, which dictates how calls will be routed when they reach the Lync Mediation servers. This opens up new migration strategies, and requires fewer modifications to systems outside of Lync such as the IP PBX or media gateway.