How many channels are in an ISDN PRI connection?

2B+D

2D+B

23D+B

23B+D

D) 23B+D

Explanation:

ISDN stands for Integrated Services Digital Network.

PRI stands for Primary Rate Interface.

ISDN operates on two different service levels:

-Basic Rate Interface (BRI) is used by individuals operating on a small scale.

-Primary Rate Interface (PRI) is used by larger businesses and organizations.

ISDN PRI consists of 23B channels and one 64Kbps D channel represented as 23B+D.

23B + D

Explanation:

ISDN stands for Integrated Services Digital Network. It makes use of two types of channels:

B type : which is used for carrying data/voice D type : which carries control and signalling information.

ISDN supports two different service levels:

Basic Rate Interface (BRI) - home and small users Primary Rate Interface (PRI) - larger enterprise scenarios

Both BRI and PRI make use of set of B and D type channels for data transfer.

BRI consists of 2 B channels and 1 D channel whereas PRI consists of 23 B channels and 1 D channel.