[Asterisk-Users] Difference between E1 and PRI

[Eric Bishop]

Hi all,

I have seen the term E1 and PRI used interchangably when referring to
a voice service with 30B channels and 1 D channel. Are they just
different terms for the same thing or is there some technical
difference. Even Newton's telco dictonary seemed a bit fuzzy on this
topic. I have seen it said the PRi is a protocol that runs on top of
E1. Is this true?