Uses fixed length, 53 byte “cells”
- 5 bytes of overhead and 48 bytes of user data
- More suitable for real time transmissions.
Provides extensive QoS information
- Enables setting of precise priorities among different types of transmissions (i.e. voice, video & e-mail)
- Same rates as SONET: 51.8, 466.5, 622.08 Mpbs
- New versions: T1 ATM (1.5 Mbps), T3 ATM (45 Mbps)