The NW-BM85-000 Bridge MUX is considered Data Terminal EQUIPMENT (DTE) device. Modems are Data Communication EQUIPMENT (DCE). A modem cable must be used when connecting the bridge to the modem.
The following list identifies the type of cable and naming convention used to connect to different types of EQUIPMENT.

DTE - DCE: Modem Cable or Straight Through Cable
DTE - DTE: Null-Modem Cable (crossed cables)
DCE - DCE: Tail Circuit Cable Interface Mechanical