HDLC - High-level Data Link Control
Short for High-level Data Link Control, a transmission protocol used at the data link layer (layer 2) of the OSI seven layer model for data communications. The HDLC protocol embeds information in a data frame that allows devices to control data flow and correct errors. HDLC is an ISO standard developed from the Synchronous Data Link Control (SDLC)standard proposed by IBM in the 1970's.
For any HDLC communications session, one station is designated primary and the other secondary. A session can use one of the following connection modes, which determine how the primary and secondary stations interact.
The Link Access Procedure-Balanced (LAP-B) and Link Access Procedure D-channel (LAP-D)protocols are subsets of HDLC.
It's not just your lawnmower and household tools that your neighbor won't return. Our top picks include everything from updating device firmware... Read More »Interesting Times: Transformation in the IT Channel
Business transformation will remain the buzzword of the moment as channel firms continue to assess the direction of their companies in the age of... Read More »What is a Virtual Private network (VPN)?
Companies and organizations will use a VPN to communicate confidentially over a public network and to send voice, video or data. Read More »
From wacky alarm clocks to lecture hall tools and after class entertainment, these Android apps are a good fit for a student's life and budget. Read More »Network Fundamentals Study Guide
A network is a group of two or more computer systems or devices, linked together to share resources, exchange files and electronic communications.... Read More »Computer Architecture Study Guide
This Webopedia study guide describes the different parts of a computer system and their relations. Read More »
Stay up to date on the latest developments in Internet terminology with a free weekly newsletter from Webopedia. Join to subscribe now.
- Watch Datamation's editor James Maguire moderate roundtable discussions with tech experts from companies such as Accenture, Dell, Blue Jeans Network, Microsoft and more »