Working on an old 2524 w/T1 CSU/DSU on S0. This CSU/DSU is very different that that for the 2600. I am having trouble following the instruction at this URL http://www.cisco.com/univercd/cc/td/doc/product/software/ios11/cbook/cinterf c.htm Can anyone share some experience ? Thanks Ruihai Serial0 is down, line protocol is down Hardware is HD64570 with FT1 CSU/DSU _________________________________ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]