In a previous recipe, we discussed M:N trunk routing, and we said that associating multiple gateways with a single Mediation Server adds resiliency and flexibility. In this recipe, we will see how to obtain three different results: load balancing, failover, and least cost routing.
There are some limitations and compatibility requirements while implementing the solutions explained in this recipe. We can find a short explanation about them in the TechNet post M:N trunk in Lync Server 2013 at http://technet.microsoft.com/en-us/library/gg398971.aspx.
In the following recipe, we will add some gateways to our scenario and we will assume that they are already configured. The international.wonderland.lab gateway is the least costly gateway for international calls from UK to France. To enable failover routing, we will add another gateway failover.wonderland.lab.
Lync will load balance voice traffic using a round robin between the PSTN gateways defined in the various voice routes.
UK-International-France
:Set-CsPstnUsage -Identity global -Usage @{add="UK-International-France"}
^(?:00)(33d{9-10})
normalization ruleinternational.wonderland.lab
gatewayThe previously mentioned parameters are shown in the following screenshot:
Set-CsPstnUsage -Identity global -Usage @{add="UK-Failover"}
Now, we will perform the following steps:
UK-National-Failover
. It will be associated with the same normalization rules of the UK-London-National route.The following image highlights the two voice routes:
Ken Lasko has dedicated a series of posts to Lync Enterprise Voice Misconceptions that also include important information about failover routing at http://ucken.blogspot.ch/2014/09/EVMisconceptionsRouting.html.
Keenan Crockett, in a blog post dedicated to Lync Server 2010, Distinguishing Between Voice Routes Configured for Load Balancing vs. Voice Policies Configured for Failover and Least Cost Routing in Lync Server 2010 (http://blogs.perficient.com/microsoft/2011/08/distinguishing-between-voice-routes-configured-for-load-balancing-vs-voice-policies-configured-for-failover-and-least-cost-routing-in-lync-server-2010/) outlined some scenarios for the different configurations, also pointing out some wrong ways to realize them.