T23G and T48G Fails to include transport=tcp in contact header

[JMComstock]

Hi. We just tried that on both phones:

On T48G

REGISTER sip:p92dk.voiceelements.com SIP/2.0
Via: SIP/2.0/TCP 38.75.197.28:5060;rport;branch=z9hG4bK4157743088
..
Contact: <sip:101@38.75.197.28:5060>
..
User-Agent: Yealink SIP-T48G 35.80.0.70
Content-Length: 0

On T23G

REGISTER sip:p92dk.voiceelements.com SIP/2.0
Via: SIP/2.0/TCP 192.168.1.51:5060;rport;branch=z9hG4bK3745717080
..
Contact: <sip:104@192.168.1.51:5060>
..
User-Agent: Yealink SIP-T23G 44.80.0.70
Content-Length: 0

Same issue. I think it is not working correctly due to the NAPTR.

When I change the Transport to "TCP" and put in the address that the NAPTR resolves to then it works (NOT USING NAPTR):

REGISTER sip:pbx11.voiceelements.com:5080 SIP/2.0
Via: SIP/2.0/TCP 192.168.1.74:5060;rport;branch=z9hG4bK700385971
...
Contact: <sip:125@192.168.1.74:5060;transport=TCP>
User-Agent: Yealink SIP-T23G 44.80.0.70
...
Content-Length: 0

Putting back to NATPR breaks it again.

Thanks for the quick response!