I am currently testing the new T-46g model, and am having an issue with the SRV records that our system uses. T-2x models do not have a problem with the same address. It appears that it is only attempting an a-record lookup on the address, and not the full NAPTR\SRV lookup.
Registering via UDP with our a-record works fine, and I really do like this new model!
; <<>> DiG 9.9.2-P1 <<>> _sip._udp.********.*******.com SRV
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 51495
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;_sip._udp.********.*******.com. IN SRV
;; ANSWER SECTION:
_sip._udp.********.*******.com. 300 IN SRV 100 10 5060 ********.*******.com.
_sip._udp.********.*******.com. 300 IN SRV 10 10 5060 ********.*******.com.
;; Query time: 64 msec
;; SERVER: 127.0.1.1#53(127.0.1.1)
;; WHEN: Thu Jul 11 13:36:18 2013
;; MSG SIZE rcvd: 160
-------------------------------------
Jul 11 18:59:34 SIP [384]: SUA <5+notice>[000] host=[********.*******.com], transport=[3], port=[5060], family=[2]
Jul 11 18:59:34 SIP [384]: DNS <5+notice>[DNS] ********.*******.com is not found in dns cache
Jul 11 18:59:34 SIP [384]: DNS <5+notice>[DNS] set DNS timeout: [3000], tries: [2]
Jul 11 18:59:34 SIP [384]: DNS <5+notice>[DNS] About to query [********.*******.com] IN A/AAAA
Jul 11 18:59:34 SIP [384]: DNS <3+error >[DNS] query error: [DNS server returned answer with no data]
Jul 11 18:59:34 SIP [384]: SUA <5+notice>[000] DNS query : DNS query error
I have "solved" this issue after reading the admin guide a little closer. The behavior is a little different than previous models, which may cause some confusion.
"If a port is set to 0 and the transport type is set to DNS-NAPTR, NAPTR and SRV queries will be tried before falling back to A queries. If no port is found through the DNS query, 5060 will be used. If an explicit port (except 0) is specified and the transport type is set to DNS-NAPTR, the only lookup will be an A query"
*edit -- Redacted server addresses due to attempted access.
In previous models(even the similar T-38), SRV records would still be attempted when the port is set to the default of 5060. On the T-46, you must manually set the port to "0" if you wish to use SRV. Ideally, this behavior would be matched to the older phone models, for consistency. Otherwise, it may be a good idea to set the default port to "0" when setting the transport to NAPTR\SRV, as it doesn't make much sense for the default setting to automatically disable the transport you select.
DNS-SRV Record lookup fails -- *Solved* 
