[Freeswitch-users] Periodic SIP messaging on bridged call

I'm using freeswitch for call control and just ran into an unexpected requirement for SIP keep-alive messaging. I've taken a look at the various keep-alive options on the wiki, including "all-reg-options-ping" and none seem to fit my requirements - I have an outbound call to an unregistered endpoint which expects a SIP MESSAGE every 60 seconds. Can I register an outbound call destination before-hand so all-reg-options-ping takes effect? Unfortunately, I don't have any control over these requirements. Is there a way to do this? Thanks, Scott