Alan Freedman -- The Computer Language Company - Computer Desktop Encyclopedia
Computer Desktop Encyclopedia
Longest-Running Tech Reference on the Planet

A CDE Definition

You'll love The Computer Desktop Encyclopedia (CDE) for Tech Term of the Day (TTOD)


Microcom Protocol

See MNP.


(Microcom Networking Protocol) A family of communications protocols from Microcom, Inc., Norwood, MA, that have become de facto standards for error correction (classes 2 through 4) and data compression (class 5). In 1997, Compaq acquired Microcom.

Class 1: Half-duplex asynchronous transmission.
This is an earlier mode that is no longer used.

Class 2: Full-duplex asynchronous transmission.

Class 3: Full-duplex synchronous transmission
using HDLC framing techniques and 64-byte
blocks. Start/stop bits are stripped.

Class 4: Increased throughput. Shorter headers,
frames up to 256 bytes. Some vendors adjust frame
size based on line quality.

Class 5: Compresses data up to two times.

Class 6: Starts at V.22bis modulation and
switches to V.29 if possible. Uses pseudo-
duplexing ping-pong method for faster
turnaround of V.29 transmission.

Class 7: Compresses data up to three times.

Class 8: Not in use.

Class 9: Adds Piggy-back Acknowledgment** and
selective retransmission for more efficient
data transport. Provides better performance over
variety of links.

Class 10: Adds Adverse Channel Enhancements** for
better transmission on rural, cellular and other
noisy lines.

** Proprietary Microcom techniques.

Personal Use Only

Before/After Your Search Term
microcassetteMicrocomputer Industry Association
microcellMicrocomputer Managers Association
microchip artMicrodata
microchip implantmicrodisplay
microchip moduleMicrodrive
microcodemicroelectromechanical systems

Terms By Topic
Click any of the following categories for a list of fundamental terms.
Computer Words You Gotta KnowSystem design
Job categoriesUnix/Linux
Interesting stuffPersonal computers
InternetIndustrial Automation/Process Control
Communications & networkingAssociations/Standards organizations
HistoryDesktop publishing
ProgrammingHealthcare IT
System design