Verilink AS2000: The Basics (880-502981-001) Product Manual - Manual (Page 173)

Acronyms and Definitions
Verilink Access System 2000: Basics Glossary-53
Z
zero-byte timeslot interchange (ZBTSI) Technique for using 8 kbit/s
framing component of a T1 to
allow 64 kbit/s for timeslots over
an alternate mark inversion
(AMI) facility. No longer used,
replaced by B8ZS.
zero code suppression The insertion of a “one” bit to
prevent the transmission of eight
or more consecutive “zero” bits.