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PRI and E1 defined

PRI and E1 defined, with links for more information.

What is PRI? Is there any difference between PRI and E1?
"PRI" stands for Primary Rate Interface, and is a level of service in the Integrated Services Digital Network (ISDN) intended for large users. The link above should provide you with a better understanding of the term.

E1 (or E-1) is a digital transmission format. It's the European equivalent of the North American T-carrier system format. The E1 is the line used to deliver PRI. To learn more about E1, see our definition of E-carrier system.

This was last published in January 2007

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