General SBC/remote phone question

[Oliver Broad]

Installed some new phones at our office. Lets say my boss decides he wants one at home...

My first choice would be a VPN bridge, "vanilla" SIP appeared to work across a bridge, but I don't know if I can auto-provision across a subnet boundry?

Second choice would be a Raspberry PI as SBC, but how much configuring would it need, obviously I'd have to set up the memory card beforehand but could he just take it and plug it into his home LAN and let DHCP do the rest or would I need to "remote" into it to finish configuring it for his network?

Alternatively am I overcomplicating things, can a supported and pre-provisioned phone (one phone not a branch office) find its server across the internet without needing "help" from a SBC or VPN?

 

[JohnS_3CX]

My first choice would be a VPN bridge, "vanilla" SIP appeared to work across a bridge, but I don't know if I can auto-provision across a subnet boundry?

Yes, could work but will require good knowledge of VPN and testing - not ideal

Second choice would be a Raspberry PI as SBC, but how much configuring would it need, obviously I'd have to set up the memory card beforehand but could he just take it and plug it into his home LAN and let DHCP do the rest or would I need to "remote" into it to finish configuring it for his network?

Best all round choice, secure and supports remote provisioning.

Alternatively am I overcomplicating things, can a supported and pre-provisioned phone (one phone not a branch office) find its server across the internet without needing "help" from a SBC or VPN?

Yes, using STUN setup but it requires that you open ports on his home router otherwise it may stop working - not ideal

 

[Oliver Broad]

OK so VPN requires a router change, which may not be welcomed, and opening ports is a whole can of worms so lets say I go with SBC

Looking at the install instructions it looks as if I need "console" access to the PI (keyboard and monitor) in order to set it up, and if it needs a static IP baked into the setup then it'll be hard to pre-configure.

Could the SBC run successfully with a DHCP pool IP address? I know there are downsides to pool addresses but that way I could finish the install here then hand it over to him to just plug in.

 

[JohnS_3CX]

Yes, the SBC will work using DHCP but the problem that will most likely arise is that as soon as it's IP changes, the the phone will immediately stop working.

So try to prepare from before using DHCP, and once he installs it and has everything up and running, you can perhaps remote into his PC, then from there SSH into the Pi, and switch it to static.

Once this is done, he can plug in his phone (which should be factory reset already) and then you can provision it normally from your management console.

 

[AWS2P]

Other option could be to pre known a free IP from Boss's LAN, set that IP,subnet and gateway as static in PI NIC settings at ending settings before giving it to your boss.
You can test it before if you have for example a 4G router you can set in same ip range as your boss

 

[JohnS_3CX]

Other option could be to pre known a free IP from Boss's LAN, set that IP,subnet and gateway as static in PI NIC settings at ending settings before giving it to your boss.
You can test it before if you have for example a 4G router you can set in same ip range as your boss

Yes but if that doesn't play out, he will lose all access to the Pi and will have to have it returned to be reconfigured - so something to be aware of @Oliver Broad

 

[AWS2P]

To be honnest chances are very few to get it not working if like i said you test it before on a 4G router you set in same LAN IP range
this is my way of doing and never got any bad surprises

 

[SteveITS]

In this situation would it work to give the home PC a static IP and install the Windows SBC on it? Less to buy and get plugged in, but the PC needs to be left on.
Or of course just use the web client or Windows client, which is what we do at home with a headset.

 

[JohnS_3CX]

Agreed, and he also has the mobile client to case closed

But let's not get off topic, the OP asked a hypothetical for a deskphone.

He will need to assign a static IP otherwise risk malfunction. Remote in to the PC, SSH into the Pi, and switch to static. Simple and fast.