The multichannel E1/PRI port adapters (PA-MC-2E1 and PA-MC-8E) integrate data service unit (DSU) functionality and E1 channel support into the Cisco router. The PA-MC-2E1 or PA-MC-8E1 port adapter provides two or eight independent E1 (120-ohm) connections via RJ-48C connectors. The PA-MC-8E1 port adapter can provide up to 128 separate full-duplex High-Level Data Link Control (HDLC) channelized E1, fractional E1, full E1, or unframed E1 interfaces and the PA-MC-2E1 port adapter can provide up to 62 separate full-duplex HDLC channelized E1, fractional E1, full E1, or unframed E1 interfaces.