A new trainee is setting up a router in a test lab, and he asks you to describe the use of the connector marked BRI on the router. Which is a correct use for this connecter?
A. A WAN interface for a T1 connection
B. A LAN interface to connect to a switch
C. An interface to connect a console cable
D. A WAN interface for an ISDN connection
Correct Answer: D
Explanation:
The connector marked BRI is used for an Integrated Services Digital Network (ISDN) connection, specifically a basic rate interface (BRI). An ISDN basic rate interface provides three channels: a D channel for control signaling, and two B or bearer channels for data, resulting in 128 bits of bandwidth.
A WAN interface for a T1 connection would be connected to a serial port on the router, not the BRI interface. It would not accept a basic rate ISDN connection.
A LAN interface to connect to a switch would be an Ethernet connection that used either an RJ-45 connector or a legacy AUI connector. It would not accept a basic rate ISDN connection
An interface to a console connector will look like an RJ-45 Ethernet connector but will only accept a console or rollover cable, and is used to manage the router. It would not accept a basic rate ISDN connection.
These various ports can be seen on the backplane of a router as shown below:
