Tele-Communication (Telecom) Terms Glossary and Dictionary
LAP-D: Link Access Procedure, D-Channel
Link Access Procedure, D-Channel (LAP-D), a Layer 2 protocol in the ISDN suite, is used to do call setup and other signaling over the D Channel. Data transmissions take place on B channels. LAP-D is almost identical to the X.25 LAP-B protocol. LAPD is defined in the ITU Q.921 protocol.