2012/11/6 Klaus Darilion <klaus.mailinglists(a)pernau.at>at>:
Kamailio does the following lookups:
1. NAPTR
cisco.com (no result)
2. SRV
_sip._udp.cisco.com (NXDOMAIN)
3. A
cisco.com -> Bingo -> use SIP over UDP to Cisco's web server :-(
Then really wrong...
After NAPTR query (with no result) it should look for SRV records for
TLS, TCP and then UDP (maybe also SCTP) in an order configured by
local policy (Kamailio DNS settings).
This is really clear in RFC 3263 section 4.1:
If no NAPTR records are found, the client constructs SRV queries for
those transport protocols it supports, and does a query for each.
Queries are done using the service identifier "_sip" for SIP URIs and
"_sips" for SIPS URIs. A particular transport is supported if the
query is successful. The client MAY use any transport protocol it
desires which is supported by the server.
If no SRV records are found, the client SHOULD use TCP for a SIPS
URI, and UDP for a SIP URI. However, another transport protocol,
such as TCP, MAY be used if the guidelines of SIP mandate it for this
particular request.
Why is this not implemented?
Issue open at
http://sip-router.org/tracker/index.php?do=details&task_id=253
--
Iñaki Baz Castillo
<ibc(a)aliax.net>