DocumentCode :
1018953
Title :
Omissions and ambiguities in CCITT Recommendation Q.921
Author :
Gallardo, José Rosario ; Sanchez, Jaime
Author_Institution :
George Washington Univ., Washington, DC, USA
Volume :
32
Issue :
2
fYear :
1994
Firstpage :
88
Lastpage :
94
Abstract :
The data link layer protocol for the integrated services digital network (ISDN) user/network interface, known as link access protocol-D (LAPD), is a protocol that operates at layer 2 of the open systems interconnection (OSI) architecture. Its purpose is to safely convey information between layer 3 entities using the D-channel. The information types that LAPD is intended to transport include call control signaling, packet mode communications, and management information. Observations are made in this article about what are, in the authors´ opinion, the most confusing points of CCITT Recommendation Q.921 with comments related to data link layer address field, broadcast connections, terminal endpoint identifier (TEI) management procedures, layer 2 frames exchange, and connection management entity response to MDL-error indication primitives. This article intends solely to clarify the recommendations so that their concepts and procedures become easier to understand and implement, which can lead to significant saving of time for those who must eventually use LAPD procedures or develop the software for handling them.<>
Keywords :
ISDN; network interfaces; open systems; protocols; telecommunication network management; user interfaces; CCITT Recommendation Q.921; D-channel; ISDN; LAPD; MDL-error indication primitives; OSI architecture; TEI management procedures; broadcast connections; call control signaling; connection management entity response; data link layer address field; data link layer protocol; frames exchange; integrated services digital network; layer 2; link access protocol-D; management information; open systems interconnection; packet mode communications; protocol; terminal endpoint identifier; user/network interface; Access protocols; Communication system control; Computer errors; Data engineering; Error correction; ISDN; Information management; Intelligent networks; Open systems; Permission;
fLanguage :
English
Journal_Title :
Communications Magazine, IEEE
Publisher :
ieee
ISSN :
0163-6804
Type :
jour
DOI :
10.1109/35.259804
Filename :
259804
Link To Document :
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