[This is pre-release documentation and subject to change in future releases. This topic's current status is: Milestone-Ready]

Topic Last Modified: 2010-07-13

This section describes the DNS records that are required for deployment of Enterprise pools.

DNS Records for Enterprise Pools

The following table specifies DNS requirements for Microsoft Communications Server 2010 Enterprise pool deployment.

DNS Requirements for an Enterprise Pool

Deployment scenario DNS requirement

Enterprise pool with multiple Front End Servers and a hardware load balancer (whether or not DNS load balancing is also deployed on that pool)

An internal A record that resolves the FQDN of the Enterprise pool to the virtual IP address of the load balancer.

Enterprise pool with DNS load balancing deployed

A set of internal A records that resolve the FQDN of the pool to the IP address of each server in the pool. There must be one of these A records for each server in the pool.

Enterprise pool with DNS load balancing deployed

A set of internal A records that resolve the FQDN of each server in the pool to the IP address of that server. For more information see DNS Load Balancing.

Enterprise pool with a single Front End Server and a dedicated Back-End Database but no load balancer

An internal A record that resolves the FQDN of the Enterprise pool to the IP address of the single Enterprise Edition server.

An internal URL for Web conferencing that is different from the default pool FQDN

An internal A record that resolves the host name portion of the URL to the virtual IP of the Web conferencing load balancer (or single Front End Server if appropriate).

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 Enterprise pool 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 Enterprise pool 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 Enterprise pool hosting Device Update Service and obtain updates. Otherwise, devices obtain this 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.

The following table shows an example of the DNS records required for the internal Web farm FQDN.

Example DNS Records for Internal Web Farm FQDN

Internal Web farm FQDN Pool FQDN DNS A record(s)

EEpool.contoso.com

EEpool.contoso.com

DNS A record for EEpool.contoso.com that resolves to the virtual IP (VIP) address of the load balancer used by the Enterprise Edition servers in the pool.

In this case, the load balancer distributes SIP traffic to the Front End Servers and HTTP(S) traffic to the Web Components Servers.

Webint.contoso.com

EEpool.contoso.com

DNS A record for the EEpool.contoso.com that resolves to the VIP address of the load balancer used by the Front End Servers.

DNS A record for Webint.contoso.com that resolves to the VIP address of the load balancer used by the Web Components Servers.