[VOIPSEC] simple point to point voip (ATA) connection?

[Zenaan Harkness]

Hi, I have two analog telephone adaptors ATAs - similar to Grandstream
488s, which allows me to convert analogue phones into IP streams.

The config server for these devices speaks of SIP and NAT/ STUN settings.

Can anyone assist me in what I need to do to create a simple
point-to-point call, essentially by entering IP addresses manually?

The ultimate purpose is so that I can tunnel such connection through
ssh tunnel/ forwarded ports.

But the first step is to make the connection.

My machine is Ubuntu.

Do I need a SIP server?

If so, how can I ensure the RTP stream goes through an ssl forwarded
port - ie, how do I ensure the RTP stream goes to a local port, which
I then forward?

Thanks in advance
Zen