Failover Internet

[Techops.pl]

We're contemplating the a failover internet connection and were wondering what impact it would have on our VOIP system. From my understanding of reading some other threads, we'd need to be able to transfer our VOIP Trunk from ISP 1 to ISP 2, which means that ISP 2 would also need to be a VOIP provider, correct?

Is there something else? that needs to be done to transition voips from one provider to the other?

 

[leejor]

It all depends on what is actually going to happen during this change. If this involves a change of public IP, then there may be some complications if 3CX has been installed with a static IP. What-ever provider you are using will have to be aware of the IP change, either through a re-registration, or some other means. Some require IP authentication.

You may want to provide additional details on how you expect to handle the Failover (hardware involved?) as others may have gone though the same exercise and have some suggestions.

 

[Techops.pl]

Thanks for the response.

The voip provider is Netia in Poland.

I have also sent them an email if authentication can be completed to the trunk from a non netia public IP.

Yes, the internet connections will be completely different, the current internet is from cable, and the backup will be LTE.

How would we know if 3cx was installed with a static IP?

Alan

 

[Techops.pl]

I contacted our Trunk providers and was informed that we'd need to supply the failover IP address so they can add it to the whitelist of incoming connections.

Now the only thing to figure out is if anything would need to be changed on the 3cx side.

Alan

 

[prb123]

Any update on this. We just tried to get this answered by 3CX support and got nowhere.

Scenario:
Single 3CX Phone System. Running as a Hyper-V VM with Fault Tolerance, behind a Cisco ASA 5505 or 5506 with SLA based automatic fail over. One connection is a Comcast Business Class Cable Connection other is a bonded T1. Both have Static Public IPs. Our SIP providers both can route to a secondary IP if the first does not respond for inbound calls.

Need:
Need to be able to tell 3CX about the secondary Public IP (or just have them sniff it out).

All testing has been problematic. Without updating Public IP and restarting Services we wind up with all kinds of one-way audio issues all traceable back to the SIP Headers from 3CX bearing the wrong public IP.

 

[leejor]

With past versions of 3CX (up to 12.5), using something like a DDNS service (and STUN) allowed you to have a Dynamic public IP, which, in essence, would be happening if you changed your ISP. In versions 14 and 15, it is expected that you now have a static public IP/Domain. There are some workarounds available, if you know what you are doing, but they are not officially supported, or encouraged, and could cause other issues down the road.

If your VoIP provider is the only, outside entity that need to know what you public IP is, then there may be a way that you could employ a DDNS service so that they were aware of the IP change, unfortunately, 3CX would still continue to "announce" the hard coded public IP that you first entered.

 

[nickjhunt]

Your Sip trunk should be supported by most carriers. 3cx will register with your voip provider over any line and should allow outgoing calls ok. When a call is made however the voip stream will contain the static address entered in 3cx console network settings. If this is incorrect then when you recieve an incoming call it will terminate after 30 seconds which is the max period a call will maintain without an ack.
If you failover to another internet provider you just need to update this static ip address and restart the 3cx service (media service I think). Other issue you will get is any remote clients you have setup by ip address or dns will fail as your pBX is no longer contactable on the original IP. DDNS is a way of resolving this issue though I believe V15 will be a big step towards resolving this issue for good.

 

[andreaschr]

Hi nickjhunt,

In version 15 if you go to Settings - > Network -> and enable Dynamic Public ip PBX will make regular checks of your Public IP .
If the public ip change you will receive an email from PBX that public ip change and automatically update the public ip.
Let me know if this is what you are looking for.