I'm having some issues configuring DNS SRV support for these particular phone models.
I've been able to make the following work for the SRV record:
_sip._udp.example.com => A example.com
Proxy Field:
example.com -- Enable DNS SRV, Use Prefix
Now, my question is if example.com ALSO exists as an A record, and _sip._udp.example.com does NOT exist as an SRV record:
Proxy Field:
example.com -- Enable DNS SRV, Use Prefix -- does not work
example.com -- Enable DNS SRV, Do not Use Prefix -- works, but uses the A record example.com
The problem is according to RFC3263 4.2:
If no SRV records were found, the client performs an A or AAAA record
lookup of the domain name. The result will be a list of IP
addresses, each of which can be contacted using the transport
protocol determined previously, at the default port for that
transport. Processing then proceeds as described above for an
explicit port once the A or AAAA records have been looked up.
So, the expected behavior should be if both Enable DNS SRV and Use Prefix are enabled, and _sip._udp.example.com DOES NOT EXIST as an SRV record, the client should try to do an A lookup with example.com as it's contents.
Is there a way to configure this behavior on the client?