Microsoft® Lync® Server 2013 Unleashed Second Edition

Direct Inward Dialing

The simplest dial plan possible within Lync Server 2010 is when each user in the organization has a direct DID number. DIDs are unique across the PSTN, and therefore unique within the Lync Server deployment. A PSTN caller or an internal user can use the same dial string to reach another user when DIDs are assigned to each user in the organization.

DIDs also typically map to a user’s internal extension. For example, at Company ABC’s San Francisco office, Alice has a DID of [phone], but internal users can simply dial 3234, the last four digits of her extension, to reach Alice. This gives the flexibility of numbers being unique across the site, but with the capability for PSTN callers to reach users directly. Internal ...