DNS Requirements for Push Notifications

As described earlier, push notifications require federation with the Microsoft Push Notification Clearing House. For this service to function properly, the appropriate DNS records must be deployed to support inbound federation to the organization. This includes the DNS SRV records for federation autodiscovery. The Microsoft Push Notification Clearing House does not have the capability for manually defining a Lync Access Edge Server for federation; therefore, when push notification communicating is happening, the service must validate the federation connection using the DNS SRV records.

For push notifications to work, be sure to deploy the _sipfederationtls._tcp.<sipDomain> DNS SRV record, and point this record to the Access Edge Server used for federation.