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

Topic Last Modified: 2010-07-18

This topic describes how to configure the Domain Name System (DNS) records that you are required to create in Microsoft Communications Server 2010 deployments and those required for automatic client sign in. When you create an Enterprise pool, Setup creates Active Directory objects and settings for the pool, including the pool fully qualified domain name (FQDN). For clients to be able to connect to the pool, the FQDN of the pool must be registered in DNS. You must create DNS SRV records in your internal DNS for every Session Initiation Protocol (SIP) domain. This procedure assumes that your internal DNS has zones for your SIP user domains.

Configure a DNS SRV record

  1. On the DNS server, click Start, click Administrative Tools, and then click DNS.

  2. In the console tree for your SIP domain, expand Forward Lookup Zones, and then right-click the SIP domain in which Communications Server 2010 will be installed.

  3. Click Other New Records.

  4. In Select a resource record type, click Service Location (SRV), and then click Create Record.

  5. Click Service, and then type _sipinternaltls.

  6. Click Protocol, and then type _tcp.

  7. Click Port Number, and then type 5061.

  8. Click Host offering this service, and then type the FQDN of the pool.

  9. Click OK, and then click Done.

To verify the creation of a DNS SRV record

  1. Log on to a client computer in the domain with an account that is a member of the Administrators group or has equivalent permissions.

  2. Click Start, and then click Run.

  3. In the Open box, type cmd, and then click OK.

  4. At the command prompt, type nslookup, and then press ENTER.

  5. Type set type=srv, and then press ENTER.

  6. Type _sipinternaltls._tcp.example.com, and then press ENTER. The output displayed for the TLS record is as follows:

    Server: <dns server>.example.com

    Address: <IP address of DNS server>

    Non-authoritative answer:

    _sipinternaltls._tcp.example.com SRV service location:

    priority = 0

    weight = 0

    port = 5061

    svr hostname = poolname.example.com

    poolname.example.com internet address = <virtual IP Address of the load balancer> or <IP address of a single Enterprise Edition server for pools with only one Enterprise Edition server>

  7. When you are finished, at the command prompt, type exit, and then press ENTER.

To verify that the FQDN of the Enterprise pool can be resolved

  1. Log on to a client computer in the domain.

  2. Click Start, and then click Run.

  3. In the Open box, type cmd, and then click OK.

  4. At the command prompt, type ping <FQDN of the Enterprise pool>, and then press ENTER.

  5. Verify that you receive a response similar to the following, where the IP address returned is the IP address of the load balancer for your Enterprise pool or, in the case of an Enterprise pool with a single Enterprise Edition server, the IP address of the Enterprise Edition server:

    Reply from 172.27.176.117: bytes=32 time<1ms TTL=127

    Reply from 172.27.176.117: bytes=32 time<1ms TTL=127

    Reply from 172.27.176.117: bytes=32 time<1ms TTL=127

    Reply from 172.27.176.117: bytes=32 time<1ms TTL=127