ATIS 1000602.1996(S2019)

This standard specifies the Link Access Procedure on the D-channel, LAPD. The purpose of LAPD is to convey information between layer-3 entities across the ISDN user-network interface using the D-channel. LAPD is a protocol operating at the data-link layer of the OSI architecture. The frame structure, elements of procedure, format of fields, and procedures for the proper operation of LAPD are specified. Formerly known as T1.602-1996(R2009).