Can I do this without Asterisk?

I have a simple single line requirement: to dial my home analog POTS line to call home country users when I am traveling overseas.

I have a Sipura SPA3000 and the phone line port is connected to my home line wall jack. Can I connect a SIP client, eg Linphone, and connect to the SPA3000 directly, or is a SIP PBX the minimum requirement?

I have a VPN server at home so please ignore any network related issues for the moment.