PRI

avatar
Created by
M

Cards (7)

  • Primary Rate Interface (PRI) is an ISDN circuit, and it can be used for voice and data.
  • When you purchase an ISDN circuit, you basically purchase a T1 lease line with ISDN signaling.
  • A T1 has 24 channels of 64 Kbps and is 1472 Kbps (1.4722 Mbps) of bandwidth. This is how ISDN excels when it is used for voice communications, since the D channel communicates call information for the other 23 channels to both ends (provider and PBX).
    • In doing this call setup, it avoids something called call collisions.
  • Call collisions: happen when a call is coming in and goingn out on the same channel.
  • It is a popular technology for voice but not for data.
  • The ISDN functions by using one of the channels as a control channel called the D (delta) channel.
    The other 23 channels are called the B (bearer) channels; this is sometimes noted in shorthand as 23B + D.
  • The D channel will control call setup, and the B channel will carry data or voice aclls.