PRI

Primary Rate Interface: An ISDN standard for provisioning of 1.544 Mbit/s (DS1 - North America, Japan, et al) or 2.048 Mbit/s (E1 - Europe) ISDN services. DS1 is 23 "B" channels of 64 kbit/s each and one signalling "D" channel of 64 kbit/s/ E1 is 30 "B" channels of 64 kbit/s each and one signalling "D" channel of 64 kbit/s.