We have a DACS unit made by an Asian Telecom company whose E-Net port is not user-configurable. Always does 10/100 auto-negotiate. Dozens are installed and working fine. We have two that are tied to two seperate 2950's using IOS v12.1 and after 48 hours or so, we can no longer telnet in to these devices. You can ping the unit, and you can get in via serial port. DACS units have been replaced to no avail. Any suggestions?