Self Host Onsite Backup?

[greatchoice]

We are planning to deploy a 32SC Enterprise system however we are trying to figure out the best course of action

We host the servers on Vultr normally however this location is concerned if the facility loses internet and backup internet, how can they communicate internally without the need for external connection

We are understanding that if we use a self hosted system on premise, that would not require needed external internet to communicate, or are we wrong on this?

Is there another alternative option to ensure that there is always communication with the IP phones on the LAN?

The client is attempting worst case scenario in which there is a small percentage change but feels there are other providers that overcome this challenge natively that 3CX does not

 

[SteveITS]

Users would be able to call each other but not externally. Eventually 3CX needs Internet, e.g. to activate.External users e.g. cell phone app can’t connect in of course.

Any other VoIP solution also needs the IP part…

They could use SD-WAN across multiple ISPs but their scenario is already multiple ISP failure.

 

[NicholasP_3CX]

If the main concern is to always have internal communications active then yes, the on premises installation is the way to go. That way the phone will always be connected to the PBX internally. You would lose access to your SIP trunk in that case. You could also have 1-2 analog or ISDN lines connected through a gateway locally as a backup of that as well.

Now if the internet is down, the main SIP Trunk wont be active and the PBX will go to the gateway to process the calls.