Cisco WIC-1B-S/T Card :
One ISDN BRI port (S/T interface, requires external NT-1).
Can go into slot “W0” or “W1” of the 1E2W, 2E2W, and 1E1R2W Network Modules.
Supported in NM-1FE1R2W, NM-1FE2W, NM-2FE2W, NM-2W
A WIC36-1B-S/T can be used in a different network module in the same chassis.