Which statement is correct about ISDN Basic Rate Interface?
A.
It offers 30 B channels and 1 D channel.
B.
It offers 23 B channels and 1 D channel.
C.
It offers 2 B channels and 1 D channel.
D.
It offers 1 B channel and 2 D channels.
Explanation:
Integrated Services Digital Network (ISDN) Basic Rate Interface (BRI) offers two B channels which
carry user data at 64 Kbps each, and one control and signaling D channel operating at 16 Kbps.
Answer “It offers 23 B channels and 1 D channel.” describes ISDN Primary Rate Interface (PRI) for
NorthAmerica and Japan , with 23 B channels at 64 Kbps and one 64 Kbps D channel, for a total
throughput of 1.544 Mbps. Answer “It offers 30 B channels and 1 D channel.” Describes ISDN PRI for
Europe , Australia , and other parts of the world, with 30 64 Kbps B channels and one D channel, for
a total throughput of 2.048 Mbps. Answer “It offers 1 B channel and 2 D channels.” is a distracter.
Source: Internetworking Technologies Handbook, Second Edition (Cisco Press, 1998).