Hi, a customer of ours is running a CS1000E on a nortel data network. The problem they experiencing is some of the IP phones intermittently freezes up and loose connectivity to the CS1000. To resolve this issue you have to reboot the phone which solves the problem for a few minutes When i test the phone on a different CS1000 it seems to be stable without freezing up. Could this be a firmware issue on the phone or the signalling server or maybe a port setting on the 5520 data switches?