Request for command examples: 'listen', 'relate_client', 'relate_server'

I have written an iRule to transparently handle implicit and explicit FTPS termination. I've posted the rule to http://devcentral.f5.com/wiki/defau...ation.html . It has just a couple minor issues left to iron out, but is otherwise working fine. However, I'd really like to get rid of the pasv port tracking mechanism I've created. I think I might be reinventing the wheel there.

From what I can tell, the 'TCP::unused_port' and 'listen' commands, along with potentially the 'relate_client' and/or 'relate_server' commands could be used to instruct the F5 to listen on an unused port for an incoming pasv connection related to the control channel connection. This would eliminate a whole swath of TCL global array lookups as well as the TCL IP ACLs I've created. I could get rid of my reinvented wheel, so to say.

That said, I can't determine how to properly use the 'listen' or 'relate_client'/'relate_server' commands and the wiki entries are a bit vague. I've attempted some trial and error here, but have been unsuccessful. Can anyone shed some light on how these are used? I've searched high and low for examples but haven't found any. I'd really love to clean up that FTPS iRule and remove my ad hoc port management. I think there might be others who could benefit from this iRule if I could get it in tip-top shape. Thanks!