Dear nanog, Is anyone experiencing similar problem that we are experiencing??? Configuration as follow. cisco 7500 Hardware is CT3IP CT3 H/W Version : 5.0.0, CT3 ROM Version: 1.2, CT3 F/W Version: 2.8.0 via T1 line provided by WC. Adtram TSU v.35 cisco2500. Adtram is configured to get network clock and all recommended configuration given by Atram techs. but it does not hurt go over once again. It appeared that sort of incompatiblities btwn cisco 2500 and TSU? ie when T1 goes down, CS light is off. and need to reboot to get Adtram to get T1 back. Yes, we have replaced TSU and cable. We even switched to different serial interface. Any suggestion? /_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/ Tatsuya Kawasaki KIVEX.com (Division of Allegiance Telecom) Unlock the Power of the Internet URL:www.KIVEX.com Phone 301.215.6777 Fax 301.215.5991 Affiliation given for identification not representation /_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/