host -t SRV _some_service._tcp.yourdomain.com
_some_service._tcp.yourdomain.com has SRV record 100 1 5061 target_hostname.

where: 100 -priority; 1 weight; 5061 port

c:\> nslookup
> set type=any
> set verbose
> _some_service._tcp.yourdomain.com
_some_service._tcp.yourdomain.com      SRV service location:
          priority       = 100
          weight         = 1
          port           = 5061
          svr hostname   = target_hostname