Hello, I am using openser-1.1 and have the standard script from onsip. I am using Mediaproxy for NAT traversal. Most of my clients register for days with no issues. A few clients after say a day of operation suddenly start giving getting de-registered. I can see the ATA or UAC trying to register to openser but openser gives a reply back to the UAC saying "401 Unauthorized". The UAC's which give this issue are behind standard home grade wireless routers (netgear/linksys type). Any idea why this may happen. Thanks in advance Roger