| A | B |
|---|
| ATM adaptation layer | Service-dependent sublayer of the data link layer. |
| Dual-attached concentrator | FDDI or CDDI concentrator |
| Dual attachment station | Device attached to both the primary and the secondary FDDI rings |
| data link control layer | Layer 2 in the SNA architectural model |
| Local-area network | High-speed, low-error data network |
| LAN emulation | . Technology that allows an ATM network to function as a LAN backbone |
| Line card control | Process that runs on the NP for each CLC |
| X.21 | ITU-T standard for serial communications over synchronous digital lines. |
| Terminal Access Controller | Internet host that accepts terminal connections from dial-up lines |
| Terminal Access Controller Access Control System | Authentication protocol, developed by the DDN community, that provides remote access authentication and related services, |
