I have a identical pair of 4507r with super 2+. For some reason I cannot get a ethernet connection between the two. Physically connecting a Cat 5 cable between the two. I have also tried using the GBIC slots with fiber but no luck. But If I but a put 3560g in between and than there is a connection and I can pass data or voip. What I want to do is feed one 4507r from the other which is connected to our fiber backbone