SDLC and derivatives (4)
LAP - Link-Access Procedure; LAPB - LAP Balanced
- HDLC modified by ITU-T (formerly CCITT)
- subset of HDLC; present in X.25 protocol stack
- restricted to ABM transfer mode, appropriate for combined stations
IEEE802.2
- HDLC modified by IEEE; very popular
- often referred as Logical Link Control (LLC) incorporated in IEEE 802.3, 802.4, 802.5
QLLC - Qualified Logical Link Control
- defined by IBM: enables SNA data to be transported across X.25 networks