List of information technology initialisms

From Wikipedia, the free encyclopedia

The table below lists information technology initialisms and acronyms in common and current usage. These acronyms are used to discuss LAN, internet, WAN, routing and switching protocols, and their applicable organizations.[1][2][3] The table contains only current, common, non-proprietary initialisms that are specific to information technology. Most of these initialisms appear in IT career certification exams such as CompTIA A+.

Abbreviation Meaning Primary Applicability[4] Normative Reference
ACK Acknowledgement Transport and other layers TCP/IP, for example. RFC 793
ACL Access control list Security, application layer Access control list, Cisco overview
ADSL Asymmetric digital subscriber line Telecom ITU-T G.992.5 Annex M, for example
AES Advanced Encryption Standard Security U.S. FIPS PUB 197
ANSI American National Standards Institute Organization ANSI
API Application Programming Interface Software API
ARP Address Resolution Protocol Link layer RFC 1122
ATM Asynchronous Transfer Mode Telecom ATM cell description
BGP Border Gateway Protocol (routing protocol) Application layer, Routers RFC 4271
BSS Basic service set (Wi-Fi) Wireless IEEE Std 802.11-2007
CAT Category (e.g. CAT-5 cable) Physical layer ANSI/TIA/EIA-568-B.1-2001
CCITT (obs.) Standards organization that has been replaced by ITU-T Organization ITU-T
CHAP Challenge-Handshake Authentication Protocol (PPP) Security, telecom RFC 1994
CIDR Classless Inter-Domain Routing Architecture RFC 1518 RFC 1519
CIR Committed Information Rate (Frame Relay) Telecom RFC 1490 RFC 1973 RFC 2427
CLI Command line interpreter Hardware Catalyst 6500 Series Command Reference, 7.6, for example
CPE Customer premises equipment Telecom Telecom Glossary
CPU Central processing Unit Microprocessor Wikipedia
CRC Cyclic redundancy check Link and other layers 24 References here.
CRC-16-CCITT Cyclic redundancy check (X.25, HDLC) Link layers Reference on CRC page.
CRT Cathode Ray Tube Television set, Computer Monitor Cathode ray tube
CSMA/CA Carrier sense multiple access / collision avoidance Wireless IEEE Std 802.11 Downloads
CSMA/CD Carrier sense multiple access / collision detection Physical layer IEEE Std 802.3TM-2002
CSU/DSU Channel service unit / data service unit Telecom Telecom Glossary
CMOS Complementary metal-oxide semiconductor Utility CMOS
DAM Database activity monitoring Security Database activity monitoring
DAM Digital asset management Internet Layer Digital asset management
DCE Data communications equipment Telecom Telecom Glossary
DEC (obs.) Digital Equipment Corporation Organization Digital Equipment Corporation formally Purchased by Compaq in 1998. Merged with Hewlett-Packard 2002.
DES Data Encryption Standard (obs. See AES) Security Federal Information Processing Standard (FIPS) FIPS-46-3
DHCP Dynamic Host Configuration Protocol Application layer, Internet Layer RFC 2131 and others
DIMM Dual In-line Memory Module Hardware DIMM
DNS Domain Name System Application layer Over 30 RFCs here.
DRAM Dynamic random-access memory Hardware Dynamic random-access memory
DSL Digital subscriber line Telecom Telecom Glossary
DSLAM Digital subscriber line access multiplexer Telecom Telecom Glossary (proposed)
DTE Data Terminal Equipment Telecom Telecom Glossary
DMI Desktop Management Interface Utility Desktop Management Interface
EHA Ethernet Hardware Address (MAC address) Link layer IEEE Std 802 IEEE OUI Assignments
EIA Electronics Industry Alliance Organization EIA
EIGRP Enhanced Interior Gateway Routing Protocol Internet Layer Cisco Doc ID: 16406
EMAC Ethernet Media Access Control Link Layer
EOF End Of Frame (HDLC, etc.) Link layer HDLC framing
ESS Extended service set (Wi-Fi group) Wireless IEEE Std 802.11-2007
FCC Federal Communications Commission (US) Organization US FCC
FCS Frame check sequence (Ethernet) Link layer Ethernet Frame IEEE Std 802.3
FDDI Fiber Distributed Data Interface Link layer American National Standards Institute X3T9.5 (now X3T12), ISO/IEC 9314-x
FTP File Transfer Protocol Application layer RFC 959 and others
GBIC Gigabit interface converter Hardware Seagate Specification
gbps Gigabit per second Physical layer Gigabit per second
GEPOF Gigabit Ethernet (over) Plastic Optical Fiber Physical layer IEEE P802.3bv
GMAC Gigabit Ethernet Media Access Control Link Layer
HDLC High-level Data Link Control Link layer ISO 13239
HTTP HyperText Transfer Protocol Application layer W3C Change History for HTTP
HTTPS HyperText Transfer Protocol Secure Transport and other layers SSL 3.0 Specification
IaaS Infrastructure as a service Cloud Services IaaS Microsoft Docs
IANA Internet Assigned Number Authority Organization IANA
ICaaS Integration Capability as a Service Organization ICaaS
ICMP Internet Control Message Protocol Internet Layer RFC 792
IDF Intermediate distribution frame Physical layer Structured cabling or Telecom Glossary
IDS Intrusion Detection System Security Wikipedia
IEEE Institute for Electrical and Electronic Engineers Organization IEEE
IETF Internet Engineering Task Force Organization IETF
IMAP Internet Message Access Protocol Application layer RFC 3501
IP Internet Protocol Internet Layer RFC 791 RFC 1606
IPS Intrusion prevention system Security "NIST - Guide to Intrusion Detection and Prevention Systems (IDPS)". 2007-02. Retrieved 2010-08-24.
IS-IS Intermediate System to Intermediate System (routing protocol) Internet Layer ISO/IEC 10589:2002
ISDN Integrated Services Digital Network Telecom IEC Area 716-xx
ISP Internet service provider Telecom Telecom Glossary
ITU-T International Telecommunication Union Organization
kbps Kilobit per second Physical layer Kilobit per second
LACP Link Aggregation Control Protocol Data link layer
LAN Local area network Link and other layers Telecom Glossary
LAPB Link Access Procedure, Balanced (x.25) Telecom ITU-T Recommendation X.222
LAPF Link-access procedure for Frame Relay Telecom RFC 1490
LLC Logical link control Link layer Telecom Glossary
MAC Media access control Link layer IEEE Std 802.3 and 802.11, for example
MAM Media access management (related to Digital asset management) Internet layer Wikipedia
MAN Metropolitan area network Telecom Telecom Glossary
Mbps Megabits per second Physical layer Megabit_per_second
MC Multiple choice IT Professional Certification About certification exams
MDF Main distribution frame Physical layer Glossary See also Structured cabling
MIB Management information base (SNMP) Application layer RFC 3418
MII Media-independent Interface Link layer
MoCA Multimedia over Coax Alliance Organization Multimedia over Coax Alliance
MPLS Multiprotocol Label Switching network technology
MTU Maximum Transmission Unit Multiple layers
NAC Network access control Link and other layers IEEE 802.1x
NAS Network-attached storage Hardware / Storage Computer data storage
NAT Network Address Translation Internet Layer Cisco Internet Protocol Journal: A look Inside Network Address Translators
NBMA Non-Broadcast Multiple Access (e.g. Frame Relay ATM) Telecom See ATM, Frame Relay and X.25, for examples.
NIC Network Interface Card Physical layer Telecom Glossary
NRZ Non-return-to-zero Physical layer Federal Standard 1037C
NRZI Non-return to zero inverted Physical layer Federal Standard 1037C
NVRAM Non-volatile RAM Hardware Sample vendor data here
OSI Open System Interconnect (joint ISO and ITU standard) Organization ISO/IEC 9594-5:2005 Open Systems Interconnection Protocol Specifications
OSPF Open Shortest Path First (routing protocol) Internet Layer RFC 2238
OUI Organization Unique Identifier Link and other layers IEEE OUI Assignments
PAP Password authentication protocol Security RFC 1334
PAT Port address translation Internet Layer RFC 1918
PaaS Platform as a service Cloud Computing/Service Platform as a service
PC Personal computer (host) Hardware
PIM Personal information manager Software category
PCM Pulse-code modulation Physical layer ITU-T G.711
PDU Protocol data unit (such as segment, packet, frame, etc.) Multiple layers Fed Std 1037C
POP3 Post Office Protocol, version 3 Application layer RFC 1939
POP Point of presence Telecom Telecom Glossary
POST Power-on self test Hardware Cisco Catalyst 2800 User Guide, for example
POTS Plain old telephone service Telecom Telecom Glossary
PPP Point-to-point Protocol Telecom RFC 1661
PPTP Point-to-Point Tunneling Protocol Telecom RFC 2637
PTT Public Telephone and Telegraph Telecom Telecom Glossary or Free Dictionary
PVST Per-VLAN Spanning Tree Link layer Cisco's introduction to Spanning Tree Protocol
RADIUS Remote Authentication Dial-In User Service Security RFC 2865
RAM Random Access Memory Physical layer Telecom Glossary
RARP Reverse ARP Link layer RFC 903
RIMM Rambus In-line Memory Module Hardware Wikipedia
RFC Request for Comments Multiple layers IETF's RFC Index
RIP Routing Information Protocol Internet Layer RFC 2453, for RIP version 2
RLL Run-Length Limited Physical layer RLL is used in a wide range of encodings.
ROM Read-Only Memory Hardware Telecom Glossary
RSTP Rapid Spanning Tree Protocol Link layer IEEE 802.1w - Rapid Reconfiguration of Spanning Tree
RTP Real-time Transport Protocol Application layer RFC 3550
SaaS Software as a service Cloud Computing/Service Software as a service Microsoft Docs
SDLC Synchronous Data Link Control Link layer Cisco Technology Handbook: SDLC and Derivatives
SDN Software-defined networking Architecture Software-defined networking
SFD Start-of-frame delimiter (Ethernet, HDLC, etc.) Link layer IEEE 802.3 (Ethernet), or RFC 2687 (HDLC), for examples
SFP Small form-factor pluggable Hardware Seagate Specification
S-HTTP Secure HTTP (rarely used) Transport and other layers RFC 2660 See also https
SLARP Serial Line ARP (Address Resolution Protocol) Link and other layers Archived Cisco Serial Line Encapsulation extension
SLIP Serial Line Internet Protocol (obs.) Telecom RFC 1055
SIMM Single In-line Memory Module Hardware Wikipedia
SMTP Simple Mail Transfer Protocol Application layer RFC 5321
SNA Systems Network Architecture (IBM) Multiple layers SNA Protocol Suite
SNAP SubNet Access Protocol Link layer IEEE 802 Overview and Architecture
SNMP Simple Network Management Protocol Application layer RFC 1155, RFC 3410 thru RFC 3418 and others
SOF Start of frame Link layer IEEE 802.3 (Ethernet), or RFC 2687 (HDLC), for examples
SRAM Static random access memory Hardware PC Guide's Definition
SSH Secure shell Application layer RFC 4252
SSID Service set identifier (Wi-Fi) Wireless IEEE 802.11
STP Spanning Tree Protocol Link layer Cisco's Introduction to Spanning Tree Protocol
SYN (TCP) Synchronization Link and other layers RFC 793 and many others
TCP/IP Transmission Control Protocol/Internet Protocol Transport layer RFC 793 and many others
TDM Time-division multiplexing Physical layer Fed Std 1037C
TFTP Trivial File Transfer Protocol Application layer RFC 1350
TIA Telecommunications Industry Alliance Organization Telecommunications Industry Association
TOFU Trust On First Use Security Improving SSH-style Host Authentication with Multi-Path Probing
UDP User Datagram Protocol Transport layer RFC 768
URL Uniform Resource Locator Web address URL spec (1994)
USB Universal Serial Bus Physical and other layers USB 3.0 Specification
UTP Unshielded twisted pair Physical Many versions are defined by TIA, such as: TIA-568-B
VC Virtual circuit Transport and other layers Telecom Glossary
VLAN Virtual local area network Link layer IEEE 802.1Q
VLSM Variable-length subnet masking Architecture RFC 1518 RFC 1519
VM Virtual machine virtualization/emulation Virtual machine
VPN Virtual private network Application layer Virtual Private Network Consortium
W3C World Wide Web Consortium Organization W3C
WAN Wide-area network Telecom Telecom Glossary
WEP Wired Equivalent Privacy Wireless IEEE 802.11
Wi-Fi An implementation of IEEE wireless communication standard 802.11 Wireless Wi-Fi Alliance
WLC Wireless LAN Controller Wireless Cisco
WPA Wi-Fi Protected Access Security IEEE 802.11i
www World Wide Web Architecture W3C Consortium

See also[edit]


  1. ^ Lammle, Todd (2008). CCNA IOS Commands. Wiley Publishing, Inc. ISBN 978-1-58720-182-0.
  2. ^ Odem, Wendell (2008). CCENT/CCNA ICND1 Official Exam Certification Guide, Second Edition. Cisco Press. ISBN 978-0-470-17560-6.
  3. ^ CCNA Exploration 4.0 5.0 Routing Protocols and Concepts Student Lab Manual. Cisco Press.
  4. ^ The ISO model is used for layer names.