CSMA/CD

Technology & Computing abbreviation · Networking

CSMA/CD
Stands forCarrier-sense multiple access with collision detection
CategoriesTechnology & Computing

CSMA/CD stands for Carrier-sense multiple access with collision detection, a networking abbreviation.

The media access method of classic shared Ethernet: a device listens for silence before transmitting, detects when another device transmits at the same moment, stops, and retries after a random delay. It let many computers share one coaxial cable or hub.

Example: Explain why CSMA/CD is unnecessary on a full-duplex switched Ethernet link.

Usage notes

Modern switched, full-duplex Ethernet has no collisions, so CSMA/CD survives mainly in textbooks and certification exams. Wi-Fi uses a related method, CSMA/CA (collision avoidance), because a radio cannot reliably hear collisions while transmitting. After each successive collision the random waiting range doubles, a scheme called binary exponential backoff.

More networking abbreviations

  • BGP – Border Gateway Protocol
  • CGNAT – Carrier-grade NAT
  • CIDR – Classless Inter-Domain Routing
  • CIFS – Common Internet File System
  • CNAME – Canonical name (record)
  • CRC – Cyclic redundancy check
  • DDNS – Dynamic DNS
  • DHCP – Dynamic Host Configuration Protocol
  • DMZ – Demilitarized zone
  • DNS – Domain Name System
  • DNSSEC – Domain Name System Security Extensions
  • DoH – DNS over HTTPS

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