ATIS 1000602 1996 Edition, September 1, 1996
Integrated Services Digital Network (ISDN) – Data-Link Layer Signaling Specification for Application at the User- Network Interface
Includes all amendments and changes through Reaffirmation Notice , 1996
Scope and purpose
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.
This standard specifies the use of LAPD on a duplex, bit-transparent D-channel on an ISDN interface.