Hi,
2006/5/9, Cseke Tamas <[EMAIL PROTECTED]>:
>> That means, if one proxy dies during the session, the UA'll make a
>> DNS SRV lookup, find the other proxy, and send the BYE to it instead
>> of the proxy, which served the INVITE?
>
>
> not quite - all sequential request (within the dialog) are routed
> based on the route set (the Record Route hdr added by the proxies on
> the path). The headers contains IP addresses, so basically no DNS
> lookup is done for sequential requests. An alternative will be to
> configure your proxy to put DNS name instead of IP in the RR hdr.
>
I 'd like the UAs to make only DNS lookup, when one proxy fails, if the
proxy put domain name in The RR header, the UA must do a DNS lookup in
every request, isn't it?
It should be (that's why it's always recommended to use FQDNs instead
of IPs in SIP headers).....but I bet thousands of beers that many UAs
won't do SRV lookup for every message.
First of all thanks the replies!
Problem is the same, i wanna send a transaction to another proxy if one
dies.
But a RR header for the whole dialog is valid, i've got a suggestion to
use FQDNs...
I quess this way it should work, please someone take a look, if i
missunderstood something...
In the scenario there is 4 outbound proxy, the message will be send in
the so called SIP trapezoid (UAC->Outbound proxy -> Inbound proxy -> UAS)
The INVITE transaction is sent successfully to one outbound proxy, but
this proxy goes down, and the BYE transaction should go to another proxy
in the same dialog.
DNS SRV for failover and load balancing
_sip._udp IN SRV 0 6 proxy1.outboundproxydomain.com
_sip._udp IN SRV 0 4 proxy2.outboundproxydomain.com
_sip._udp IN SRV 1 6 proxy3.outboundproxydomain.com
_sip._udp IN SRV 1 4 proxy4.outboundproxydomain.com
Address records
outboundproxydomain.com A 217.xxx.xxx.195
outboundproxydomain.com A 217.xxx.xxx.196
outboundproxydomain.com A 217.xxx.xxx.197
outboundproxydomain.com A 217.xxx.xxx.198
proxy1.outboundproxydomain.com A 217.xxx.xxx.195
proxy2.outboundproxydomain.com A 217.xxx.xxx.196
proxy3.outboundproxydomain.com A 217.xxx.xxx.197
proxy4.outboundproxydomain.com A 217.xxx.xxx.198
INVITE
______
UAC
INVITE sip:[EMAIL PROTECTED] SIP/2.0
Contact: <sip:[EMAIL PROTECTED]>
DNS lookup for outbound proxy (dig -t SRV _sip._udp.outboundproxydomain.com)
Choose proxy1.outboundproxydomain.com
dig -t A proxy1.outboundproxydomain.com -> 217.xxx.xxx.195
Send message to 217.xxx.xxx.195
Outbound proxy(217.xxx.xxx.195)
INVITE sip:[EMAIL PROTECTED] SIP/2.0
Record-Route: <sip:outboundproxydomain.com;lr>
Contact: <sip:[EMAIL PROTECTED]>
Record-route ONLY its domain name.
Lookup inbound proxy, send message to it.
Inbound proxy
INVITE sip:[EMAIL PROTECTED] SIP/2.0
Record-Route: <sip:proxy.domain.com
Record-Route: <sip:outboundproxydomain.com;lr>
Contact: <sip:[EMAIL PROTECTED]>
UAS
INVITE sip:[EMAIL PROTECTED] SIP/2.0
Record-Route: <sip:proxy.domain.com
Record-Route: <sip:outboundproxydomain.com;lr>
Contact: <sip:[EMAIL PROTECTED]>
....
BYE
___
UAC
BYE sip:[EMAIL PROTECTED] SIP/2.0
Route: <sip:outboundproxydomain.com;lr>
Route: <sip:proxy.domain.com;lr>
Contact: <sip:[EMAIL PROTECTED]>
Most important part!!!
lookup proxy (dig -t A outboundproxydomain.com)
217.xxx.xxx.195 failed
send message 217.xxx.xxx.196 (proxy2.outboundproxydomain.com)
Outbound proxy (217.xxx.xxx.196):
BYE sip:[EMAIL PROTECTED] SIP/2.0
Route: <sip:proxy.domain.com;lr>
Contact: <sip:[EMAIL PROTECTED]>
Inbound proxy:
BYE sip:[EMAIL PROTECTED] SIP/2.0
Contact: <sip:[EMAIL PROTECTED]>
UAS
BYE sip:[EMAIL PROTECTED] SIP/2.0
Contact: <sip:[EMAIL PROTECTED]>
Thanks in advance,
Tamas
_______________________________________________
Users mailing list
[email protected]
http://openser.org/cgi-bin/mailman/listinfo/users
