The I.431/430 Networking standards are recommendations produced by the
ITU. They are Layer 1 specifications for
ISDN
Integrated Services Digital Network (ISDN) is a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the digitalised circuits of the public switched telephone network. Work ...
networks, using either an E1 or T1 circuit. The
I.431 standard is known as the '
PRI Physical Layer' whereas the I.430 is known as the '
BRI Physical Layer'.
External links
I.430 : Basic user-network interface - Layer 1 specificationfrom the ITU
ITU-T recommendations
ITU-T I Series Recommendations