# Abbreviations and Acronyms

Abbreviation or Acronym | Term
--- | ---
A |
AAA | authentication, authorization, and accounting
AAAA | authentication, authorization, accounting, and address assignment
AAL | ATM Adaptation Layer
ABR | area border router
AC | alternating current; access concentrator
ACCM | Async Control Character Map
ADSL | asymmetric digital subscriber line
AESA | ATM end system address
AF | assured forwarding
AFI | authority and format identifier
AH | authentication header
AIS | alarm indication signal
AIS-L | alarm indication signal – line
AIS-P | alarm indication signal – path
ALG | application-level gateway
ANSI | American National Standards Institute
API | application programming interface
APS | Automatic Protection Switching
ARP | Address Resolution Protocol
AS | autonomous system; Australia (re standards compliance)
AS boundary router | autonomous system boundary router
ASCII | American Standard Code for Information Interchange
ASIC | application-specific integrated circuit
AS number | autonomous system number
ATM | Asynchronous Transfer Mode
AVP | attribute-value pair
B |
backup DR | backup designated router
BECN | backward explicit congestion notification
BER | bit error rate
BERT | bit error rate test
BFD | Bidirectional Forwarding Detection (protocol)
BGP | Border Gateway Protocol
BMA | broadcast multiaccess
BOOTP | bootstrap protocol
B-RAS | Broadband Remote Access Server
BSD | Berkeley Software Distribution
C |
CA | certificate authority
CAC | call admission control (MPLS); connection admission control (ATM)
CAM | content-addressable memory
CAP | carrierless amplitude phase
CAR | committed access rate
CARS | committed access rate service
CBC | cipher block chaining
CBR | constant bit rate
CC | continuity check
CCITT | International Telegraph and Telephone Consultative Committee
CCP | Compression Control Protocol
CDV | cell delay variation
CDVT | cell delay variation tolerance
CE | customer edge device
CHAP | Challenge Handshake Authentication Protocol
CIDR | classless interdomain routing
CISPR | International Special Committee on Radio Interference
CLACL | classifier control list
CLEC | competitive local exchange carrier
CLI | command-line interface
CLNP | Connectionless Network Protocol
CLNS | Connectionless Network Service
CLP | cell loss priority
CMDA | code division multiple access
CMTS | cable modem termination system
CoA | change of authorization
cOC | channelized optical carrier
COPS | Common Open Policy Service (protocol)
CORBA | Common Object Request Broker Architecture
CoS | class of service
CPE | customer premises equipment
CPU | central processing unit
CRC | cyclic redundancy check
CR-LDP | Constraint-Based Routed Label Distribution Protocol
CR-LSP | constraint-based routed label-switched path
CSNP | complete sequence number PDU (protocol data unit)
CSU | channel service unit
CT1, CT3 | channelized T1, T3
CTI | computer telephony integration
CTS | clear to send
CTT | connection traffic table
CUL | agreement between Underwriter Laboratories and Canadian Standards Association for joint product safety approval
D |
DC | direct current
DCC | Data Country Code
DCD | data carrier detect
DCE | data communication equipment
DCM | dynamic configuration manager
DE | discard eligibility
DES; 3DES | Data Encryption Standard; triple DES
DF | don’t fragment (bit)
DHCP | Dynamic Host Configuration Protocol
DIS | designated intermediate system
DLCI | data-link connection identifier
DLCMI | data-link connection management interface
DMZ | demilitarized zone
DNIS | dialed number identification service
DNS | Domain Name System
DNS-ALG | Domain Name System – Application Level Gateway
DOCSIS | Data over Cable System Interface Specifications
DoS | denial of service
DPD | dead peer detection
DR | designated router
DS | digital signal; DiffServ
DS-BGP | dual-stack Border Gateway Protocol
DSI | dynamic subscriber interface
DSL | digital subscriber line
DSLAM | digital subscriber line access multiplexer
DSP | domain-specific part
DSR | data set ready
DSS | Digital Signature Standard
DST | Daylight Saving Time
DSU | data service unit
DTE | data terminal equipment
DTR | data terminal ready
DU | downstream unsolicited
DVMRP | Distance Vector Multicast Routing Protocol
DXI | data exchange interface (abbreviation pronounced “ dixie” )
E |
EAP | Extensible Authentication Protocol
EBGP | external Border Gateway Protocol
ECC | error checking and correction; error-checking code
ECMP | equal-cost multipath
ECP | Encryption Control Protocol
EEPROM | electrically erasable programmable read-only memory
EF | expedited forwarding
EFA | egress forwarding ASIC
EGP | exterior gateway protocol
E-LSP | EXP-inferred-PSC LSP
EN | European Norm
EPD | early packet discard
ES | end system
ESD | electrostatic discharge
ESF | extended superframe
ESI | end system identifier
ESP | Encapsulating Security Payload
EXP | experimental (refers to bits in MPLS shim header)
F |
FAT | file allocation table
FCC | Federal Communications Commission
FCS | frame check sequence
FDL | facilities data link
FE | Fast Ethernet
FE-2 | dual-port Fast Ethernet
FEC | forwarding equivalence class (abbreviation pronounced “ feck” )
FECN | forward explicit congestion notification
FERF | far-end receive failure
FFA | frame forwarding ASIC
FIB | forwarding information base
FIFO | first-in, first-out
FIN | finish (bit)
FPGA | field programmable gate array
FQDN | fully qualified domain name
FRU | field-replaceable unit
FSM | finite state machine
FTE | forwarding table entry
FTP | File Transfer Protocol
G |
Gbps | gigabits per second
GE | Gigabit Ethernet
giaddr | gateway IP address
GRE | Generic Routing Encapsulation
GRxx | (refers to Bellcore standards)
GUI | graphical user interface
H |
HAR | hierarchical assured rate
HDLC | High-Level Data Link Control; High-Speed Data Link Control
HMAC | Hashed Message Authentication Code
HO-DSP | high-order domain-specific part
HRR | hierarchical round-robin
HSSI | high-speed serial interface (abbreviation pronounced “ hissy” )
I |
I/O | input/output
IANA | Internet Assigned Numbers Authority
IAPP | Inter Access Point Protocol
IBGP | internal Border Gateway Protocol
IC CS | Industry Canada Communications Section
ICD | International Code Designator
ICMP | Internet Control Message Protocol
ICRQ | incoming-call request
ID | identification; identifying; identifier
I-DAS | integrated DHCP access server
IDI | initial domain identifier
IDP | initial domain part
IDSL | ISDN digital subscriber line
IEC | International Electrotechnical Commission
IEEE | Institute of Electrical and Electronics Engineers
IETF | Internet Engineering Task Force
IGMP | Internet Group Management Protocol
IGP | interior gateway protocol
IIF | incoming interface
IKE | Internet Key Exchange
ILEC | incumbent local exchange carrier
ILMI | Integrated Local Management Interface
InARP | Inverse Address Resolution Protocol
IOA | input/output adapter
IP | Internet Protocol
IPCP | Internet Protocol Control Protocol
IPoA | Internet Protocol over Asynchronous Transfer Mode
IPSec | Internet Protocol Security
IRDP | ICMP Router Discovery Protocol
ISAKMP | Internet Security Association and Key Management Protocol
ISDN | Integrated Services Digital Network
IS-IS | Intermediate System–to–Intermediate System
ISM | IPSec Service module
ISO | International Organization for Standardization
ISP | Internet service provider
IS Voice | Intelligent Service Voice application
ITU-T | International Telecommunication Union – Telecommunication Standardization
J |
JATE | Japan Approvals Institute for Telecommunications Terminal Equipment
JDBC | Java Database Connectivity
K |
KB | kilobyte(s)
Kbps | kilobits per second
L |
L2TP | Layer 2 Tunneling Protocol
LAC | L2TP access concentrator
LAG | link aggregation group
LAN | local area network
LCP | Link Control Protocol
LDAP | Lightweight Directory Access Protocol
LDP | Label Distribution Protocol
LED | light-emitting diode
LER | label edge router
LIB | label information base
LIP | Link Integrity Protocol
LLC | logical link control
L-LSP | label-only-inferred-PSC LSP
LMI | local management interface; link management interface
LNS | L2TP network server
LOF | loss of frame
LOP | loss of pointer
LOS | loss of signal
LSA | link-state advertisement
LSDB | link-state database
LSP | label-switched path; link-state PDU; link-state protocol
LSR | label-switching router
M |
MAC | media access control; Message Authentication Code
MAU | medium attachment unit
MB | megabyte(s)
MBGP | multicast Border Gateway Protocol
MBone | multicast backbone
Mbps | megabits per second
MBS | maximum burst size
MD5 | Message Digest 5
MDL | maintenance data link
MDx | Message Digest x (hash algorithm)
MED | multiple exit discriminator
MGTM | multicast group table manager
MIB | Management Information Base
MLFR | Multilink Frame Relay
MLPPP | Multilink Point-to-Point Protocol
motd | message of the day
MOTM | message of the minute
MP-BGP | Border Gateway Protocol multiprotocol extensions (sometimes referred to as multiprotocol Border Gateway Protocol)
MPLS | Multiprotocol Label Switching
mrinfo | multicast router information
MRRU | multilink maximum received reconstructed unit
MRU | maximum receive unit
MSDP | Multicast Source Discovery Protocol
MSO | multiple service operator
MSP | Multiplex Section Protection
MSS | maximum segment size
MTU | maximum transmission unit; multitenant unit
N |
NAK | negative acknowledgment
NAPT | Network Address Port Translation
NAS | network access server
NAT | Network Address Translation
NBMA | nonbroadcast multiaccess
NCP | Network Control Protocol
ND | Neighbor Discovery
NEBS | Network Equipment Building System
NET | network entity title
NLRI | network layer reachability information
NMC | Network Management Center
NMS | network management system
NNI | network-to-network interface
NRZ | nonreturn to zero
NRZI | nonreturn to zero inverted
NSAP | network service access point
NSF | nonstop forwarding
NSSA | not-so-stubby area (refers to OSPF routing)
NTP | Network Time Protocol
NVRAM | nonvolatile random-access memory
NVS | nonvolatile storage
O |
OAM | operations, administration, and management
OC | optical carrier
ODBC | Open Database Connectivity
OID | object identifier
OIF | outgoing interface
ORF | outbound route filter; outbound route filtering
OSI | Open Systems Interconnection
OSINLCP | OSI Internet Link Control Protocol; OSI Network Layer Control Protocol
OSPF | Open Shortest Path First
OSS | operations support system
P |
P | provider core router
PADI | PPPoE Active Discovery Initiation
PADM | PPPoE Active Discovery Message
PADN | PPPoE Active Discovery Network
PADO | PPPoE Active Discovery Offer
PADR | PPPoE Active Discovery Request
PADS | PPPoE Active Discovery Session
PADT | PPPoE Active Discovery Termination
PAP | Password Authentication Protocol
PBX | private branch exchange
PCMCIA | Personal Computer Memory Card International Association
PCR | peak cell rate
PDU | protocol data unit
PE | provider edge router
PFC | Protocol Field Compression
PFS | perfect forward secrecy
PHB | per-hop behavior
PHP | penultimate hop pop
PIB | Policy Information Base
PIM | Protocol Independent Multicast; power input module
PIM DM | Protocol Independent Multicast dense mode
PIM S-DM | Protocol Independent Multicast sparse-dense mode
PIM SM | Protocol Independent Multicast sparse mode
PIM SSM | Protocol Independent Multicast source-specific multicast
PKI | public key infrastructure
PLCP | physical layer convergence procedure
PM | policy manager
PNNI | private network-to-network interface
POP | point of presence
POS | packet over SONET
POST | power-on self-test
PPP | Point-to-Point Protocol
PPPoE | Point-to-Point Protocol over Ethernet
pps | packets per second
PROM | programmable read-only memory
PSC | per-hop scheduling class
PSNP | partial sequence number PDU (protocol data unit)
PVC | permanent virtual circuit (or connection)
Q |
QoS | quality of service
R |
RADIUS | Remote Authentication Dial-In User Service
RD | route distinguisher
RDBS | relational database system
RDI | remote defect indication
RED | random early detection
REI | remote error indication
RESV | reservation
RFC | Request for Comments
RIB | routing information base
RIP | Routing Information Protocol
RISC | reduced instruction set computing
RMI | Remote Method Invocation (Java)
RP | rendezvous point (router)
RPF | reverse-path forwarding
RSA | Rivest-Shamir-Adleman (encryption algorithm)
RSVP | Resource Reservation Protocol
RSVP-TE | Resource Reservation Protocol with traffic engineering extensions
RTM | resource threshold monitor
RTR | Response Time Reporter
RTSP | Real-Time Streaming Protocol
RWS | receive window size
RX | receive
S |
SA | security association
SAFI | subsequent address family identifier
SAR | segmentation and reassembly
SC | system controller
SCCRQ | Start-Control-Connection-Request
SCEP | Simple Certificate Enrollment Protocol
SCR | sustained cell rate
SCSI | small computer system interface (abbreviation pronounced “ scuzzy” )
SDH | Synchronous Digital Hierarchy
SDRAM | synchronous dynamic random access memory
SDSL | symmetric digital subscriber line
SDU | service data unit
SDX | Service Deployment System (formerly SSC)
SEF | severely errored framing
SES | severely errored second
SFP | small form-factor pluggable transceiver
(S,G) | source (S) of the multicast packet and the destination multicast group address (G)
SHA | Secure Hash Algorithm
SIP | SMDS Interface Protocol
SLA | service level agreement
SLARP | Serial Line Address Resolution Protocol
SM | Service line module
SMF | single-mode fiber
SMM | switch management module
SNAP | Subnetwork Access Protocol; subnetwork attachment point
SNI | SMDS network interface
SNMP | Simple Network Management Protocol
SNPA | subnet point of attachment
SNTP | Simple Network Time Protocol
SODIMM | small outline dual inline memory module
SONET | Synchronous Optical Network
SPD | security policy database
SPF | shortest path first
SPI | security parameter index
SPQ | strict-priority queues
SPVC | soft permanent virtual circuit
SQL | Structured Query Language
SRP | switch route processor
SRT | source-rooted tree
SSC | Service Selection Center (no longer used; see SDX)
SSH | Secure Shell
SSN | short sequence number
STM | Synchronous Transport module
SVC | switched virtual circuit
S-VLAN | stacked virtual local area network
SYN | synchronize (bit)
T |
TAC | Technical Assistance Center
TACACS | Terminal Access Controller Access Control System
TC | transmission convergence
TCP | Transmission Control Protocol
TE | traffic engineering
TFTP | Trivial File Transfer Protocol
TIP | terminal interface processor
TLV | type-length-value
ToS | type of service
TPID | Tag Protocol Identifier
TSM | Tunnel Service line module
TTL | time-to-live
TU | tributary unit
TUG | tributary unit group
TX | transmit
U |
U | unit of measurement for rack-mounted equipment (a U is 1.75 in., or 4.44 cm)
UBR | unspecified bit rate
UDP | User Datagram Protocol
UI | user interface
UL | Underwriter Laboratories
UMTS | universal mobile telecommunications system
UNI | user-network interface (ATM usage); user-to-network interface
UPC | user parameter control
URL | Uniform Resource Locator
USM | user-based security model
UTC | Coordinated Universal Time
V |
VAC | volts alternating current
VBR | variable bit rate
VBR-NRT | variable bit rate, non–real time
VBR-RT | variable bit rate, real time
VC | virtual circuit (or connection)
VCC | virtual channel connection
VCCI | Voluntary Control Council for Interference
VCD | virtual circuit descriptor
VCI | virtual channel identifier
VDC | volts direct current
VDSL | very-high-bit-rate digital subscriber line
VLAN | virtual local area network
VoIP | voice over Internet Protocol
VOQL | virtual output queue length
VP | virtual path
VPC | virtual path connection
VPI | virtual path identifier
VPN | virtual private network
VR | virtual router
VRF | VPN routing and forwarding instance
VRID | virtual router identifier
VRRP | Virtual Router Redundancy Protocol
VSA | vendor-specific attribute (RADIUS)
VT | virtual tributary
VTS | VPN Tunnel Server
vty | virtual terminal
W |
WAN | wide area network
WAP | wireless access point
WEP | Wired Equivalent Privacy
WFQ | weighted fair queuing
WINS | Windows Internet Name Service (Microsoft)
WLAN | wireless local area network
WLL | wireless local loop
WRED | weighted random early detection
WRR | weighted round-robin
X |
xDSL | combined term used to refer to ADSL, HDSL, SDSL, and VDSL
XFP | 10-gigabit small form-factor pluggable transceiver