Codes & Standards - Purchase
This standard contains the complete text of ccm Recommendation Q.920,
ISDN User-Network Interface Data-Link Layer - General Aspects, and eeIIT
Recommendation Q.921 , ISDN User-Network Interface - Data-Link Layer
Specification, as they will appear in the upcoming 1989 eem Blue Book.!
This standard specifies the Link Access Procedure on the D-channel,
LAPD. The pwpose ofLAPD 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 051
architecture. This standard specifies the use of LAPD on a duplex, bit-
transparent D-channel on an ISDN interface. The frame structure,
elements of procedure, format of fields, and procedures for the proper
operation of LAPD are specified.