SIP presence across more asterisk servers

Hello,
I have two asterisk boxes configured, each with its own dial plan. Those two boxes are interconnected by sip trunk.

I have set presence checking at each server up and it works fine within each server.

I´d like to know whether is possible to view presence of phones registered to remote server.

I have found FOP, but this is not solution that I want.

Thans for help.