DNS Records for Standard Edition Servers

Standard Edition server

An internal A record that resolves the FQDN of the server to its IP address.

Automatic client sign-in

For each supported SIP domain, an SRV record for _sipinternaltls._tcp.<domain> over port 5061 that maps to the FQDN of the Standard Edition server that authenticates and redirects client requests for sign-in. For details, see DNS Requirements for Automatic Client Sign-In.

Device Update Service discovery by UC devices

An internal A record with the name ucupdates-r2.<SIP domain> that resolves to the IP address of the Standard Edition server hosting Device Update Service. In the situation where an Office Communications Server 2007 R2 UC device is turned on, but a user has never logged into the device, the A record allows the device to discover the server hosting Device Update Service and obtain updates. Otherwise, devices obtain the server information though in-band provisioning the first time a user logs in. For details, see Device Update Service.

Important:
If you have an existing deployment of Software Update Server in Office Communications Server 2007, you have already created an internal A record with the name ucupdates.<SIP domain>. For Office Communications Server 2007 R2, you must create an additional DNS A record with the name ucupdates-r2.<SIP domain>.

A reverse proxy to support HTTP traffic

An external A record that resolves the external Web farm FQDN to the external IP address of the reverse proxy. Clients and UC devices use this record to connect to the reverse proxy. For details, see Determining DNS Requirements.