Appendix B. S-NAPTR Example

As an example, consider a client that wishes to resolve aaa:ex1.example.com. The client performs a NAPTR query for that domain, and the following NAPTR records are returned:

;; order pref flags service regexp replacement
IN NAPTR 50 50 "s" "aaa:diameter.tls.tcp" ""
_diameter._tls.ex1.example.com
IN NAPTR 100 50 "s" "aaa:diameter.tcp" ""
_aaa._tcp.ex1.example.com
IN NAPTR 150 50 "s" "aaa:diameter.sctp" ""
_diameter._sctp.ex1.example.com

This indicates that the server supports TLS, TCP, and SCTP in that order. If the client supports TLS, TLS will be used, targeted to a host determined by an SRV lookup of _diameter._tls.ex1.example.com. That lookup would return:

;; Priority Weight Port Target
IN SRV 0 1 5060 server1.ex1.example.com
IN SRV 0 2 5060 server2.ex1.example.com

As an alternative example, a client that wishes to resolve aaa:ex2.example.com. The client performs a NAPTR query for that domain, and the following NAPTR records are returned:

;; order pref flags service regexp replacement
IN NAPTR 150 50 "a" "aaa:diameter.tls.tcp" ""
server1.ex2.example.com
IN NAPTR 150 50 "a" "aaa:diameter.tls.tcp" ""
server2.ex2.example.com

This indicates that the server supports TCP available at the returned host names.

Appendix B. S-NAPTR Example​

Appendix B. S-NAPTR Example