The capabilities of the T1 interface
are determined by the host it's plugged
into. The 3600 NM-1E2W, NM-1E1R2W, and
NM-2E2W support one serial channel group
per WIC slot only; the NM-1FE2W,
NM-1FE1R2W, NM-2FE2W, and NM-2W support
two serial channel groups per WIC slot.