1988 was the year that CCITT released specification I.122, named Framework for Providing Additional Packet Mode Bearer Services. This release specified how LAPD protocols could be used in applications other than ISDN. Soon after, ANSI also became involved, which meant that specifications became complete.
1990 saw two other papers released:
I.293 ISDN Frame Node Bearer Services (FMBS)
I.370 Congestion Management for the Frame Relaying Bearer Service
Some of the other papers are as follows:
ANSI
CCITT
Framework
I.122
Service Description
T1.606
I.233.1
Data Transfer Protocol
T1.618
Q.922
Congestion Management
T1.606
I.370
Access Signalling
T1.617
Q.933
Q.922 (1992) defines an enhanced version of LAPD. It species, among other things:
congestion controls
transmission error checking
frame length inspection
checking of data for bytes before and after bit insertion and extraction (ie. if data is not in byte format, it will not be encapsulated in a frame
multiplexing using the address field
frame delimiting, alignment and transparency
There will be more on this topic to come by the 5th of January 1998
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