[asterisk-users] IAX port

[Duncan Turnbull]

On 10 Feb 2015, at 12:22, Jose Flores Galicia wrote:

> 2015-02-09 14:36 GMT-06:00 jg <webaccounts173 at jgoettgens.de>:
>> Hi!
>>
>> Sometimes IAX peers are not reachable and with "iax2 set debug on" I 
>> get
>> something like this
>>
>> Tx-Frame Retry[ No] -- OSeqno: 000 ISeqno: 001 Type: IAX Subclass: 
>> PONG
>> Timestamp: 00014ms  SCall: 00001  DCall: 01200 79.233.155.174:49153
>> Rx-Frame Retry[ No] -- OSeqno: 001 ISeqno: 001 Type: IAX     
>> Subclass: ACK
>> Timestamp: 00014ms  SCall: 01200  DCall: 00001 79.233.155.174:49153
>>
>> I am not sure what causes port 4569 to be replaced an an arbitrary 
>> port,
>> which could be the reason for my problem. Does someone know whether 
>> this is
>> a router related problem?
>>
>> jg

I get an occasional similar problem, we have Mikrotik firewalls and from 
tcpdump monitoring on the asterisk boxes I can see that the firewall 
(unbidden) has changed the IAX port. Usually a firewall reset and 
sometimes PBX reset combination fixes it.

Its odd as its only one direction, occurs rarely and with no obvious 
driver. So IAX is happy in one direction but not the other. And I can 
see packets in the unhappy point arriving on the wrong port.

I couldn't fix it without kicking the router/firewall so I would say its 
a router problem in the Destination NAT process.

Cheers Duncan


>>
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>
> Hi.
>
> Port is changed when NAT is applied from LAN to WAN.
> While UDP session is maintained as ESTABLISHED, that port should not 
> change.
>
> If your peer changes constantly of session port could be UDP session
> is too short in NAT table on routers.
> You can try setting qualify=1000 (which is in ms. Default is 2000),
> and see if peer keeps same port.
>
> Regards.
>
> -- 
> _____________________________________________________________________
> -- Bandwidth and Colocation Provided by http://www.api-digital.com --
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