0-UDP 
1-TCP 
2-TLS 
3-DNS-NAPTR 
If the value of this parameter is set to 3 (DNS-NAPTR), the value of the parameter 
“account.X.sip_server.Y.address” is set to a host name and the value of the parameter 
“account.X.sip_server.Y.port” is set to 0, the IP phone will perform the DNS NAPTR and SRV 
queries for the transport protocol, ports and servers. 
If the value of this parameter is set to 3 (DNS-NAPTR), the value of the parameter 
“account.X.sip_server.Y.address” is set to an IP address and the value of the parameter 
“account.X.sip_server.Y.port” is set to an explicit port (except 0), then UDP is used. 
X ranges from 1 to 16 (for SIP-T54S/T48G/T48S/T46G/T46S/T29G) 
X ranges from 1 to 12 (for SIP-T52S/T42G/T42S) 
X ranges from 1 to 6 (for SIP-T41P/T41S/T27P/T27G) 
X ranges from 1 to 3 (for SIP-T40P/T40G/T23P/T23G) 
X ranges from 1 to 2 (for SIP-T21(P) E2) 
X is equal to 1 (for SIP-T19(P) E2/CP860/CP920) 
Web User Interface: 
Account->Register->SIP Server Y->Transport 
Phone User Interface: 
None 
Description: 
Configures the way of SRV query for the IP phone to be performed when no result is 
returned from NAPTR query for account X. 
0-SRV query using UDP only 
1-SRV query using UDP, TCP and TLS 
X ranges from 1 to 16 (for SIP-T54S/T48G/T48S/T46G/T46S/T29G) 
X ranges from 1 to 12 (for SIP-T52S/T42G/T42S) 
X ranges from 1 to 6 (for SIP-T41P/T41S/T27P/T27G) 
X ranges from 1 to 3 (for SIP-T40P/T40G/T23P/T23G) 
X ranges from 1 to 2 (for SIP-T21(P) E2) 
X is equal to 1 (for SIP-T19(P) E2/CP860/CP920) 
Web User Interface: