Simple way to use phone in office and at home? VPN working

Sangoma Hardware Phones
1

I’ve got a PBXact system with Sangoma phones.
I understand internal and external templates and have phones working both in the office and outside. Is there a simple solution to making phones that can be used inside the LAN and then taken home to use over the internet?

I changed my outside test phone to use the VPN following the steps in the wiki. My external template has the outside public IP as the SIP destination and Provisioning address and VLAN 0. My internal template has VLAN2 for the office and the internal (172.16.0.5) address for SIP and Provisioning

So, is there a way to combine these 2 templates so that it recognizes if I am at home or the office? The part about those IP addresses concerns me- is it basically using the outside address for everything?

2

It needs to be done with DNS. Have an FQDN that resolves to the LAN IP in the office and a WAN IP outside.

3

Alright that makes sense and was kind of where my thoughts were heading

In the customers DNS server they would need to create something like pbx.customer.com pointing at 172.16.0.5 and in the outside world create that same DNS pbx.customer.com pointed at my public 1.2.3.4 address

In the template, for those SIP and Provisioning address use “custom” and pbx.customer.com

Where does the VLAN fit in this though? Can it be left at 2 and work on both the inside network and over the VPN?