I’m interested in adding two phones at a remote office to connect with an asterisk system at our existing network that already consists of two SoundPoint IP450 phones. The asterisk system connects to an Optonline phone line to manage inbound and outbound calls using a Tiger Jet Network Inc. Tiger3XX Modem/ISDN interface.
The remote office is using a single dynamic IP. Is the best way to connect the two new phones at the remote office to use a libreswan VPN and connect as a net-to-net road warrior from a gateway system at the remote network?
I’m considering purchasing two used SoundPoint IP450 phones from here:
This is the PoE version, but I would likely purchase power supplies for each of them.
There’s an option for “SIP Provisioning” at the time of purchase. I believe I used TFTP to provision the phones in the past, but I don’t understand enough about whether I need SIP provisioning specifically as a purchase option.