Which statement describes ISDN Basic Rate Interface (BRI)?

• A. Provides 128k of bandwidth per line.
• B. Provides 1 Mbps of bandwidth per line.
• C. Is always available in all rural locations.
• D. Is a fiber optic service.

Answer: (A)

The statement is about the bandwidth layout of ISDN Basic Rate Interface. A BRI line carries two 64 kbps B channels for user data and a 16 kbps D channel for signaling. That makes the total line rate 144 kbps, but the practical data capacity when using both B channels is 128 kbps. So describing 128k of bandwidth per line reflects the usable data speed you can achieve with BRI. The other options don’t fit: BRIs are not 1 Mbps, are not guaranteed to be available in all rural locations, and are not a fiber optic service (they run over copper).