Specifications

APPENDIX C: WAN TERMS AND ACRONYMS
C-4 WPIM-T1 LOCAL MANAGEMENT GUIDE
SDLC Synchronous Data Link Control, layer 2 (link layer) protocol
developed by IBM for SNA connectivity. Basis for HDLC.
SNA Systems Network Architecture, data communication network
architecture developed by IBM in the 1970’s.
T-1 A Bell System term that refers to the physical carrier used to
transmit a digital signal at 1.544 Mbps.
T1.617-D T1.617 Annex D, an ANSI link management protocol specifi-
cation used in Frame Relay.
TDM Time Division Multiplexing, a technique in which separate
data or voice signals are transmitted simultaneously over a sin-
gle communications medium based on time interleaving.
Timeslot A standard 64,000 bit/second channel. Synonymous with DS-0
(Digital Signal, level 0).
WAN Wide Area Network, a network spanning a large geographic
area.
WPIM WAN Physical Interface Module, Cabletron Systems modules
that provide connectivity/functionality for WAN modules such
as the BRIM-W6.