Hi!
Kamailio does not forward the received 503 response but instead generates a new 500 response. Failure routes are not activated.
U 2010/04/14 15:08:26.201865 83.136.22.111:5060 -> 83.136.32.159:5060 SIP/2.0 503 Service Unavailable Via: SIP/2.0/UDP 83.136.32.159;branch=z9hG4bK2a5a.0d5ea987.0;received=83.136.32.159 Via: SIP/2.0/UDP 10.10.0.51:5086;received=83.136.33.3;rport=5086;branch=z9hG4bK2901533893 From: sip:klaus.darilion@labs.nic.at;tag=1939498352 To: sip:01888801505641636@labs.nic.at;tag=as1b74528e Call-ID: 3387977514 CSeq: 21 INVITE Server: Asterisk PBX 1.6.2.6 Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY, INFO Supported: replaces, timer Content-Length: 0 X-Asterisk-HangupCause: Unallocated (unassigned) number X-Asterisk-HangupCauseCode: 1
U 2010/04/14 15:08:26.201865 83.136.32.159:5060 -> 83.136.22.111:5060 ACK sip:01888801505641636@labs.nic.at SIP/2.0 Via: SIP/2.0/UDP 83.136.32.159;branch=z9hG4bK2a5a.0d5ea987.0 From: sip:klaus.darilion@labs.nic.at;tag=1939498352 To: sip:01888801505641636@labs.nic.at;tag=as1b74528e Call-ID: 3387977514 CSeq: 21 ACK Max-Forwards: 69 Content-Length: 0
# U 2010/04/14 15:08:26.201865 83.136.32.159:5060 -> 83.136.33.3:5086 SIP/2.0 500 Service Unavailable Via: SIP/2.0/UDP 10.10.0.51:5086;rport=5086;branch=z9hG4bK2901533893;received=83.136.33.3 From: sip:klaus.darilion@labs.nic.at;tag=1939498352 To: sip:01888801505641636@labs.nic.at;tag=c3829fdbb3bfc7416671e56cae8e633d-a9b5 Call-ID: 3387977514 CSeq: 21 INVITE X-Info: (83.136.32.159:1035) Enforcing NAT traversal for local caller X-Info: (83.136.32.159:1035) Enforcing symmetric response routing Server: kamailio (3.0.1 (i386/linux)) Content-Length: 0
Is this a feature or a bug?
thanks klaus
2010/4/14 Klaus Darilion klaus.mailinglists@pernau.at:
Hi!
Kamailio does not forward the received 503 response but instead generates a new 500 response. Failure routes are not activated.
Is this a feature or a bug?
A RFC 3261 feature:
16.7 Response Processing
6. Choosing the best response (page 110)
A proxy which receives a 503 (Service Unavailable) response SHOULD NOT forward it upstream unless it can determine that any subsequent requests it might proxy will also generate a 503. In other words, forwarding a 503 means that the proxy knows it cannot service any requests, not just the one for the Request- URI in the request which generated the 503. If the only response that was received is a 503, the proxy SHOULD generate a 500 response and forward that upstream.