Seeking design suggestions

Hi !
I would love to have some suggestions about how to proceed to re-design a system.

Quick history, about 10-12 years ago I did design my personal PABX system (only VoIP) using Asterisk, running on a server on my premises (2Tbyte HD, 4 Gbyte RAM).
I used to work with Asterisk quite a lot in the past but are years now I’m not follow it.

The latest server did run 24h/7 for 7 years, however recently the server had some problems and basically I decided to rebuild it, adding more memory and other things (the plan is to have 4 Tbyte HD, 32 Gbyte RAM)
Among the thing to do I decided to rebuild all the services from scratch, better possibly.
Among them my PABX system based on Asterisk.

Now, I don’t remember what version I did use but considering the age of the server I would say way too old.
I’m sure Asterisk did change quite a while in the past 7 years (last time I did some updates if I recall unless some automatic update was running - the latest Ubuntu running on that server was 16.04) so I’m trying to restart as I don’t know nothing about it.
As main guidelines I’m planning to install the latest Ubuntu or PopOS! on the server but all the major services when possible, will be running in Docker.
I’m trying to isolate as much as possible the services from the machine this time.

To sum up, I’m trying to :

  • List item using a Linux server (Ubuntu or PopOS!)
  • List item run latest Asterisk on docker
  • List item look for the best solution for backup and disaster recovery
  • List item mainly only VoIP (voice and video calls)
  • List item using a lot of old Grandstream GXV 3000
  • List item looking to enhance security

Any suggestions about how to proceed ?
What is the best version to use running in docker ? I did see there are already lot of docker images around, are there documents/blog something to help to guide ?
I’m planning to document the design process to be published on my blog to help others starting from the scratch.

Thanks for any suggestion

TheFwGuy