Question : ISDN physical layer

sir,
     plz tell me the difference about BRI and PRI on physical layer
    what are connectors are used in BRI and PRI
    also tell me that what type of signaling are configured on
    BRI and PRI.
                     thanx.

Answer : ISDN physical layer

BRI consists of 2 B channels 64kb/s each; 1 D channel 16kb/s
PRI depends on where you are:

Europe PRI is
30 B channels; 1 D channel

USA PRI is
23 B channels; 1 D channel

N.B. If you have more than one PRI into a location, then you can share the D channel between PRI's (it can be used as a B channel).