4451 may not be able to do the channelized DS3. The SM-1T3/E3 should be able to do that but it will not support channelized :
http://www.cisco.com/c/en/us/products/collateral/routers/4000-series-integrated-services-routers-isr/data_sheet_c78-728546.html
Q. Does the module support channelized mode?
A. No.
-Terry
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