[OpenSIPS-Users] Source port in SIP replies

[Alexandr A. Alexandrov]

Hi Bogdan,

Well, this confuses me even more...
I though that in case opensips can not open socket on the port it 
listens on, it tries to open a socket on a port where it can, and then 
send the packet out...
This would not break any standarts, AFAIK (even though firewalls might 
get crazy about this, which is, pitifully, my case).

Regards,
Alex


06.10.2010 15:26, Bogdan-Andrei Iancu:
> Hi Alexandr,
>
> Alexandr A. Alexandrov wrote:
>    
>> Hi!
>>
>> I ran into a pretty weird situation last day. I'm using opensips-1.6.2
>> as a load balancer for several * servers.
>> Everything worked fine for months, but suddenly opensips started to use
>> ports like 56827 or 51234 (does not matter, just non-default, not the
>> one it is listening on). And the operator's system does not allow such
>> replies, it just drops them.
>> Opensips is listening on port 5070 on my system.
>>
>> Invite comes like:
>> User Datagram Protocol, Src Port: sip (5060), Dst Port: vtsas (5070)
>> INVITE sip:xxxxx at my.ip:5070;user=phone SIP/2.0
>>
>> Reply goes like:
>> User Datagram Protocol, Src Port: 52795 (52795), Dst Port: sip (5060)
>> SIP/2.0 100 Giving a try
>>
>> Normally src port is always 5070.
>>
>> So, the questions are:
>> - under what conditions does opensips decide to invent a new port?
>>      
> under no conditions - it will use only the defined interfaces from cfg...
>
> Are you sure about that port changing ? could you provide a pcap showing
> this ?
>
> Regards,
> Bogdan
>
>
>