- Open cmd
- Type: nslookup
- Type: set type=all
- Type the SRV record to list its content
For OCS 2007 R2
- External
- _sip._tls.domain.com
- Usually points to Access EDGE FQDN on port 443
- _sipfederationtls._tcp.domain.com
- Usually points to Access EDGE FQDN on port 5061
- _sip._tls.domain.com
- Internal
- _sipinternaltls._tcp.domain.com
- Usually points to Pool name with correct sip domain on port 5061
- _sipinternaltls._tcp.domain.com
For Exchange 2007/2010
- External autodiscover
- _autodiscover._tcp.domain.com
- Usually points to owa FQDN listener with NTLM negotiate on port 443
- _autodiscover._tcp.domain.com

