What are T1, ISDN and PRI forms of Voice Communications?

T1/PRI/ISDN Voice is a phone service used for carrying voice and data transmissions in a digital format. T1 meets the needs of businesses having multiple users on a system requiring fast speed and broad bandwidth. A full T1 can accommodate as many as 24 users working at one time. PRI is a telecommunications standard that means Primary Rate Interface. It describes how the 24 channels of a T1 are split into 23 “B” channels for Voice and 1 “D” channel for control signals.