[asterisk-users] Client Asterisks can't connect when main Asterisk reboot

[Administrator TOOTAI]

Le 26/03/2018 à 11:08, Antony Stone a écrit :
> On Monday 26 March 2018 at 10:58:01, Administrator TOOTAI wrote:
> 
>> Hi all,
>>
>> we are running some Asteriks (version 13 on Debian Stretch) as VM/kvm in
>> datacenter and have trunks with other Asterisk (v1.8 11 or 13) instances
>> behind FW. Problem we face is that when we reboot the DC Asterisks, the
>> trunks (SIP or IAX) become alive from DC Asterisks to clients ones but
>> UNAVAILABLE the other way.
>>
>> In clients logs we see
>>
>> Registration for 'XXX at ourDCAsteriks' timed out, trying again (Attempt
>> #5550)
>>
>> or UNREACHABLE in case of no registration or IAX
>>
>> Sometimes a restart from client Asterisks is enough (SIP or IAX reload
>> has no effect) to recover the full trunk, but in most cases we have to
>> reboot the client server :(
>>
>> If we use a VPN (OpenVPN) between Asterisks, no problem.
>>
>> What can be the problem ?
> 
> Are you doing NAT between the two servers?  Your comment about using a VPN
> makes me think you probably are.

Yes, NAT is involved.

> 
> In that case I suggest the problem is with stale connection tracking table
> entries on the machine which is doing the NAT.

OK, effectively the clients having problems are behind ISP boxes which 
means poor NAT level :( Others behind linux boxes (except one behind 
Sophos UTM) doesn't have this problem.

Thanks for your enlightenment.

Daniel