Before you deploy E9-1-1, you must already have deployed your Lync Server internal servers, including a Central Management store, a Front End pool or a Standard Edition server, one or more Mediation Servers or Mediation Server pools, and Lync Server clients. In addition, an E9-1-1 deployment requires a SIP trunk to a qualified E9-1-1 service provider or an Emergency Location Identification Number (ELIN) gateway to your public switched telephone network (PSTN). Lync Server supports using E9-1-1 service providers only inside the United States.
Configure voice usages, routes, and trunk configurations
Create a new PSTN usage record. This is the same name that is used for the PSTN Usage setting in the location policy.
Create or assign a voice route to the PSTN usage record created in the previous step and then point the gateway attribute to the E9-1-1 SIP trunk or ELIN gateway.
For a SIP trunk E9-1-1 service provider, set the trunk that will be handling E9-1-1 calls over the SIP to pass PIDF-LO data by using the Set-CsTrunkConfiguration –EnablePIDFLOSupport cmdlet.
Optionally, for a SIP trunk E9-1-1 service provider, create or assign a local PSTN route for calls that are not handled by the E9-1-1 service provider’s SIP trunk. This route will be used if the connection to the E9-1-1 service provider is not available. If supported by your E9-1-1 service provider, assign a trunk configuration rule to the gateway that translates the 911 dial string into the direct inward dialing (DID) number of the national/regional Emergency Call Response Center (ECRC).