The Lync Server Update for February 2013 included a much asked for feature: location-based routing. Location-based routing basically ensures the routes that phone calls can take are dependent on where the user is currently located.
Before the February 2013 update, the path calls would take were solely determined by the assigned Lync voice policy. Normally, call routes are somewhat local to the user (at least within the same country). If a user were to go to another office on the other side of the planet, their calls would still route via the same paths as if the user were at their home office.
Normally, this isn't a very big issue, but some countries have very strict rules about how calls may enter and exit the country. India is an example where they don't want to see any calls leave the country via the Internet. All calls must leave the country via the PSTN. Toll bypass or least-cost routing is not allowed.
Fellow Lync'er Richard Brynteson wrote up a great post on how to setup location-based routing in Lync 2013 CU1. He even put me on the spot by saying that I was working on adding location-based routing to the Optimizer. So, that pretty much meant that I had to do it.
So, in the spirit of the Lync Optimizer doing all the work required to setup Enterprise Voice in Lync, I've added an option to configure location-based routing when the Optimizer is run for a given Lync deployment.
There is a single prerequisite in order to make it all work. The Lync environment must have at least one Lync network region, site and subnet configured (preferably/obviously for the location where location-based routing is to be enabled). If call admission control has already been deployed, then this should already be done. If not, the Lync network site/subnet can be setup manually by following the guide on Technet. If AD Sites & Services has been fully populated with site/subnet information, I've created a script that will transfer this into Lync.
When the Optimizer runs, it will check to see if the deployment is running Lync 2013 and has at least one network site defined. It will then prompt the user to apply location-based routing to that site (or others if more than one site is found).
If you are unsure whether or not to apply location-based routing, then DON'T DO IT. It will ensure that all calls made from within the network site use only the routes defined for that site. It may have unintended consequences for users visiting the site. It can be undone, but if you are not comfortable with the inner workings of Lync, its best not to open up that can of worms.
As a final note, the Lync Optimizer now includes dial rules for India, which is one of the main reasons why location-based routing was added to Lync in the first place.
Best of luck out there!