[Freeswitch-users] Authorizations when using DNS SRV bug?

[Carlos S. Antunes]

Hello!

I am using Callcentric for my tests and have observed what appears to me 
a possible bug in the way Freeswitch handles DNS SRV records.

Callcentric uses DNS SRV records as a way to direct traffic to their SIP 
server. A 'srv' 'dig' of '_sip._udp.callcentric.com' returns:

_sip._udp.callcentric.com. 10025 IN     SRV     20 7 5080 
alpha6.callcentric.com.
_sip._udp.callcentric.com. 10025 IN     SRV     20 7 5080 
alpha7.callcentric.com.
_sip._udp.callcentric.com. 10025 IN     SRV     20 7 5080 
alpha1.callcentric.com.
_sip._udp.callcentric.com. 10025 IN     SRV     20 7 5080 
alpha3.callcentric.com.

Based on this information, Freeswitch appears to correctly round robin 
all available IP addresses except in a particular situation: in the 
middle of authorizations.

For example, in a registration, Freeswitch send a packet to 
alpha1.callcentric.com. Callcentric then challenges Freeswitch with a 
Proxy Authorization request. Freeswitch then sends the packet with the 
requested credentials but not necessarily to alpha1.callcentric.com! In 
many cases, instead of sticking to the 'challenging' server, Freeswitch 
round robins and sends the second packet to, one of the other servers. 
This continues for a little while and eventually, simply by luck, the 
second packet is sent to the 'challenging' Callcentric server.

Shouldn't Freeswitch stick to the same server when challenged for 
credentials? Is this a bug? Is there a way to make Freeswitch behave 
differently?

Thanks!

Carlos Antunes
Nowthor Corporation