V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

LAPB
       Link Access Procedure - Balanced (CCITT, LAP, X.25)


The Free On-line Dictionary of Computing (30 December 2018):

Link Access Protocol Balanced
LAPB

    (LAPB) X.25 layer 2 (data link layer)
   protocol.

   [Details?]

   (1996-01-22)