List of Technology terms & acronyms

Acronym	Meaning	Primary Applicability
ACK	Acknowledgement	Transport and other layers
ACL	Access control list	Security, application layer
ADSL	Asymmetric digital subscriber line	Telecom
AES	Advanced Encryption Standard	Security
ANSI	American National Standards Institute	Organization
ARP	Address Resolution Protocol	Link layer
ATM	Asynchronous Transfer Mode	Telecom
BGP	Border Gateway Protocol (routing protocol)	Application layer, Routers
BSS	Basic service set (Wi-Fi)	Wireless
CAT	Category (e.g. CAT-5 cable)	Physical layer
CCITT (obs.)	Standards organization that has been replaced by ITU-T	Organization
CHAP	Challenge-Handshake Authentication Protocol (PPP)	Security, telecom
CIDR	Classless Inter-Domain Routing	Architecture
CIR	Committed Information Rate (Frame Relay)	Telecom
CLI	Command line interpreter	Hardware
CPE	Customer premises equipment	Telecom
CRC	Cyclical redundancy check	Link and other layers
CRC-16-CCITT	Cyclical redundancy check (X.25, HDLC)	Link layers
CSMA/CA	Carrier sense multiple access / collision avoidance	Wireless
CSMA/CD	Carrier sense multiple access / collision detection	Physical layer
CSU/DSU	Channel service unit / data service unit	Telecom
DCE	Data communications equipment	Telecom
DEC (obs.)	Digital Equipment Corporation	Organization
DES	Data Encryption Standard (obs. See AES)	Security
DHCP	Dynamic Host Configuration Protocol	Application layer, Internet Layer
DNS	Domain Name System	Application layer
DRAM	Dynamic random-access memory	Hardware
DSL	Digital Subscriber Line	Telecom
DSLAM	Digital Subscriber Line Access Muliplexor	Telecom
DTE	Data Terminal Equipment	Telecom
EHA	Ethernet Hardware Address (MAC address)	Link layer
EIA	Electronics Industry Alliance	Organization
EIGRP	Enhanced Interior Gateway Routing Protocol	Internet Layer
EOF	End Of Frame (HDLC, etc.)	Link layer
ESS	Extended service set (Wi-Fi group)	Wireless
FCC	Federal Communications Commission (US)	Organization
FCS	Frame check sequence (Ethernet)	Link layer
FDDI	Fiber Distributed Data Interface	Link layer
FTP	File Transfer Protocol	Application layer
GBIC	Gigabit interface converter	Hardware
Gbps	Gigabit per second	Physical layer
HDLC	High-level Data Link Control	Link layer
http	HyperText Transfer Protocol	Application layer
https	HyperText Transfer Protocol Secure	Transport and other layers
IANA	Internet Assigned Number Authority	Organization
ICMP	Internet Control Message Protocol	Internet Layer
IDF	Intermediate distribution frame	Physical layer
IDS	Intrusion Detection System	Security
IEC	Commission Electrotechnique Internationale (French)	Organization
IEEE	Institute for Electrical and Electronic Engineers	Organization
IETF	Internet Engineering Task Force	Organization
IMAP	Internet Message Access Protocol	Application layer
IP	Internet Protocol	Internet Layer
IPS	Intrusion prevention system	Security
IS-IS	Intermediate System to Intermediate System (routing protocol)	Internet Layer
ISDN	Integrated Services Digital Network	Telecom
ISP	Internet service provider	Telecom
ITU-T	International Telecommunications Union	Organization
kbps	Kilobit per second	Physical layer
LAN	Local area network	Link and other layers
LAPB	Link Access Procedure, Balanced (x.25)	Telecom
LAPF	Link-access procedure for frame relay	Telecom
LLC	Logical link control	Link layer
MAC	Media access control	Link layer
MAN	Metropolitan area network	Telecom
Mbps	Megabits per second	Physical layer
MC	Multiple choice	IT Professional Certification
MDF	Main distribution frame	Physical layer
MIB	Management information base (SNMP)	Application layer
MPLS	Multiprotocol Label Switching	network technology
MTU	Maximum Transmission Unit	Multiple layers
NAC	Network access control	Link and other layers
NAT	Network Address Translation	Internet Layer
NBMA	Non-Broadcast Multiple Access (e.g. Frame Relay ATM)	Telecom
NIC	Network Interface Card	Physical layer
NRZ	Non-return-to-zero	Physical layer
NRZI	Non-return to zero inverted	Physical layer
NVRAM	Non-volatile RAM	Hardware
OSI	Open System Interconnect (joint ISO and ITU standard)	Organization
OSPF	Open Shortest Path First (routing protocol)	Internet Layer
OUI	Organization Unique Identifier	Link and other layers
PAP	Password authentication protocol	Security
PAT	Port address translation	Internet Layer
PC	Personal computer (host)	Hardware
PIM	Personal information manager	Software category
PCM	Pulse-code modulation	Physical layer
PDU	Protocol data unit (such as segment, packet, frame, etc.)	Multiple layers
POP3	Post Office Protocol, version 3	Application layer
POP	Point of presence	Telecom
POST	Power-on self-test	Hardware
POTS	Plain old telephone service	Telecom
PPP	Point-to-point Protocol	Telecom
PPTP	Point-to-Point Tunneling Protocol	Telecom
PTT	Public Telephone and Telegraph	Telecom
PVST	Per-VLAN Spanning Tree	Link layer
RADIUS	Remote Authentication Dial-In User Service	Security
RAM	Random Access Memory	Physical layer
RARP	Reverse ARP	Link layer
RFC	Request for Comments	Multiple layers
RIP	Routing Information Protocol	Internet Layer
RLL	Run-Length Limited	Physical layer
ROM	Read-Only Memory	Hardware
RSTP	Rapid Spanning Tree Protocol	Link layer
RTP	Real-time Transport Protocol	Application layer
SDLC	Synchronous Data Link Control	Link layer
SFD	Start-of-frame delimiter (Ethernet, HDLC, etc.)	Link layer
SFP	Small form-factor pluggable	Hardware
S-HTTP	Secure HTTP (rarely used)	Transport and other layers
SLARP	Serial Line ARP (Address Resolution Protocol)	Link and other layers
SLIP	Serial Line Internet Protocol (obs.)	Telecom
SMTP	Simple Mail Transfer Protocol	Application layer
SNA	Systems Network Architecture (IBM)	Multiple layers
SNAP	SubNet Access Protocol	Link layer
SNMP	Simple Network Management Protocol	Application layer
SOF	Start of frame	Link layer
SRAM	Static random access memory	Hardware
SSH	Secure shell	Application layer
SSID	Service set identifier (Wi-Fi)	Wireless
STP	Spanning Tree Protocol	Link layer
SYN (TCP)	Synchronization	Link and other layers
TCP/IP	Transmission Control Protocol/Internet Protocol	Transport layer
TDM	Time-division multiplexing	Physical layer
TFTP	Trivial File Transfer Protocol	Application layer
TIA	Telecommunications Industry Alliance	Organization
TOFU	Trust On First Use	Security
UDP	User Datagram Protocol	Transport layer
USB	Universal Serial Bus	Physical and other layers
UTP	Unshielded twisted pair	Physical
VC	Virtual circuit	Transport and other layers
VLAN	Virtual local area network	Link layer
VLSM	Variable-length subnet masking	Architecture
VPN	Virtual private network	Application layer
W3C	World Wide Web Consortium	Organization
WAN	Wide-area network	Telecom
WEP	Wired Equivalent Privacy	Wireless
Wi-Fi	IEEE 802.11 (Wi-Fi Alliance)	Wireless
WPA	Wi-Fi Protected Access	Security
www	World Wide Web	Architecture