I recently needed to work from home, and I brought home one of my desk phones (A Cisco 7940G) It connected to the PABX fine with NAT mode and worked for all of 60 seconds before it went unreachable to the PABX Now, I’ve fixed this before thanks to help from KungfuMonkeySlayer (http://www.kungfumonkeyslayer.co.uk/index.php/2010/04/sip-through-a-juniper-ssg5-router/) …