SIP calls Fail after power failure

[MartinB]

HI Guys

We have a bit of an issue with power here in South Africa. So they are implementing load shedding where certain parts of cities have no power for 2-8 hours daily depending on the load the power station can carry.

But this is causing issues for my clients breaking out on SIP trunks over LTE devices on OXO.

Scenario:

Client loses power for few hours and when they come back up they are unable to dial out. SIP registration is still valid and they can receive calls but they can not dial out. Only way to fix the issue is to de-register and re-register the sip account. Rebooting of the LTE or the pabx does not solve it.
This is for 1 group of clients where no third party are allowed on their network so we have to run LTE devices.


When running a trace it does not even show the trunk being seized. As though the Trunk is not available. It only shows the registration requests on the trace. It does not give me any other detail as to why the call fails. it cannot seize that sip trunk.

I have set up same setup in my lab and I can pull the power out of the system and switch off LTE but when restarting, the trunk comes up and dialing out.
It only happens when I leave the power off for couple of hours. No outbound calls after power up.
But If I leave it for another day or 2 then the account will start working again and I can make calls.

I have set registration timers and protocol timers to maximum and to minimum it does not make a difference.

The SIP provider says they can see the public IP of the LTE and they have no timers set on their side which can cause this, so the problem is between the LTE and PABX. But I cannot prove anything without the pabx being able to give me traces for failed calls. As the call does not try to establish.

I do not have the same problem on sites where we use their Local LAN to break out to SIP provider. Only LTE. Different LTE's

IF someone has any suggestions please advise?

thank you
Martin

[alex]

SIP protocol authors by default should be in hell.
So which keep-alive option is set in sip-gateway? Ping or OPTIONS?

[MartinB]

HI Alex

Thank you for the response.

They are all set up with SIP OPTION for keep alive.
Will the ICMP option be better? It makes sense that as long as the PABX can ping the provider IP it should keep alive....

Martin

[alex]

Hmm strange.

Do you have latest SW version installed?
Also check in ARS - there you can see whether SIP GW is alive or not from OXO point of view.

[MartinB]

Hi Alex

They are all on Rel 3.0 - I have upgraded my lab system to R032_021_001 on Friday so will test it again tomorrow and see if there is any difference.

thank you