Definitions in parenthesis indicate the nature of the acronym or symbol,
rather than what it stands for. Definitions including page numbers indicate
symbols whose meanings could not be confidently determined. Any help
completing these definitions is welcome.
Users of this list are strongly encouraged to take part in its development and
perfection. Suggestions for corrections, modifications, and additions to this
list are welcome and should be sent via Internet email to
sharky@cs.byu.edu.
Thank you, and enjoy.
Charlton Rose
8/5/94
SYMBOL/ACRONYM DEFINITION
10BASE2 10 Mbps, base-band, 200-m segment length
10BASE5 10 Mbps, base-band, 500-m segment length
10BROAD36 10 Mbps, broadband, 3600-m segment length
AAL ATM adaptation layer
AB signal ground
ABM asynchronous balanced mode
AC access control
AC acknowledge connectionless
AC acknowledged connectionless
ACK acknowledgment field significant
ACK acknowledge
ADCCP advanced data communication control procedures
ADCCP Advanced Data Communication Control Procedures
AK acknowledgment
ALOHA 87
AM amplitute modulation
AMI alternate mark inversion
ANS X3T9.5 (ANSI subcommittee that develops standards for HSLN)
ANSI American National Standards Institute
ANSI X3.66 187
ANSI SONET (transmission standard for 155.52 Mbps or higher over single-
mode fiber)
ANSI DS3 (transmission standard for 44.736 Mbps over coaxial cable or
optical fiber)
APD 78
ARM asynchronous response mode
ARPA Advanced Research Projects Agency
ARPANET ARPA computer network
ARQ automatic repeat request
ASCII American Standard Code for Information Interchange
ASK amplitude-shift keying
ASN.1 Abstract Syntax Notation One
AT&T
ATM asynchronous transfer mode
AU access unit
B-ISDN broadband ISDN
B8ZS bipolar with 8-zeros substitution
BA secondary transmitted data
BB secondary received data
Bc committed burst size
Be excess burst size
BECN backward explicit congestion notification
BEL bell
BER Basic Encoding Rules
BISDN (same as B-ISDN)
BNF Backus-Naur Form
BPDU bridge protocol data unit
bps bits per second
BS backspace
CA request to send
CAN cancel
CATV community antenna television
CB clear to send
CBMS computer-based message system
CBR constant bit rate
CBX computerized branch exchange
CC connection confirm
CC DCE ready/data set ready
CCIR 756
CCITT G.703 (transmission standard for 34.368 Mbs and 139.264 Mbps over
metalic medium)
CCITT International Telegraph and Telephone Consultative Committee
CCITT SDH (transmission standard for 155.52 Mbps or higher over single-
mode fiber)
CD collision detection
CD DTE ready/data terminal ready
CDT credit
CE ring indicator
CF received line signal detector
CIR committed information rate
CLNP connectionless network protocol
CLS close
CMIP common management information protocol
COP Corporation for Open Systems
CPMGR connection point manager
CR connection request
CR carriage return
CRC cyclic redundancy check
CRC-16 146
CRC-32 146
CRC-CCITT 146
CSMA carrier sense multiple access
CSMA/CD carrier-sense multiple access with collision detection
CWI virtual route change window indicator
CWRI virtual route change window reply indicator
DA destination address
DARPA 477
DB-25 159
dBmV decibel-millivolt
DBS direct broadcast satellite
dBW decibel-watt
DC disconnect confirm
DC device control
dc direct current
DCA 469
DCE data circuit-terminating equipment
DDN Defense Data Network
DE discard eligibility
DEL delete
Delta-T 588 (experimental lightweight transport protocol)
DES data encryption standard
DIS 9041 (specification for VTP)
DIS draft international standard
DISC disconnect
DLCI data link connection identifier
DLE data link escape
DM disconnected mode
DM delta modulation
DMA direct memory access
DMA 308
DOD Department of Defense
DP draft proposal
DPA 455
DQDB distributed queue, dual bus
DR disconnect request
DS-1 217 (TDM transmission format)
DS-2 217
DS3 415
DSAP destination service access point
DSAP 410
DSBSC double sideband suppressed carrier
DSBTC double sideband transmitted carrier
DT data
DTE data terminal equipment
DU data unit
EA address field extension
EA expedited acknowledgment
EBCDIC 638
ED ending delimeter
ED expedited data
EDTPDU-NR send sequence number of ED TPDU
EGP exterior gateway protocol
EHF extremely high frequency
EHKP4 550
EIA Electronics Industries Association
EIA-232-D (physical layer standard)
EIA-530 (physical layer standard)
EM end of medium
EMI electromagnetic inteference
ENQ enquiry
EOL end-of-letter
EOT end of transmission
EOT 573
ER TPDU error
ERP exterior router protocol
erp error recovery procedure
ESC escape
ETB end of transmission block
ETX end of text
FADU file access data unit
FC frame control
FCS frame check sequence
FCS frame check sequence
FDDI Fiber Distributed Data Interface
FDM frequency-division multiplexing
FECN forward explicit congestion notification
FED-STD-1003A 187
FF form feed
FIFO first in, first out
FIN no more data from sender
FIPS Federal Information Processing Standards
FIPS federal information-processing standard
FIPS PUB 71-1 187
FM frequency modulation
FMD function management data
FRMR frame reject
FS frame status
FS file separator
FSK frequency shift keying
FSK
FT3 218
FTAM File Transfer, Access, and Management
FTP file transfer protocol
G- giga-
G.703 415
GAM-T 588 (experimental lightweight transport protocol)
GFC generic flow-control
GOSIP government open systems profile
GS group separator
HDB3 high-density bipolar-3 zeros
HDLC high-level data link control
HEC 828
HF high frequency
HHUB header hub
HIC highest incoming channel
HOC highest outgoing channel
HSLN high speed local network
HT horizontal tab
HTC highest two-way channel
Hz hertz
I.441/Q.921 807
I.451/Q.931 (call control protocol)
I-frame information frame
I-H-U I heard you
I/O input/output
IBM International Business Machines
IEC Internation Electrotechnical Commission
IEEE 802 477
IEEE 802.1 486
IEEE 802.3 specification for CSMA/CD
IEEE 802.4 specification for token bus
IEEE 802.5 specification for token ring
IEEE 802.6 360
IEEE Institute of Electrical and Electronics Engineers
IEEE 802 342 (standards document)
IEEE 802.5 (token ring specification)
IHL internet header length
IHUB intermediate hub
ILD injection laser diode
IMP interface message processor
IRP interior router protocol
IS intermediate system
IS international standard
ISDN Integrated Services Digital Network
ISN initial sequence number
ISO TP4 class 4 ISO transport
ISO 8208 (X.25 standard)
ISO 8473 (ISO standard for internet protocol)
ISO International Organization for Standardization
ISO/TR 10029 (standard, specifies connection-mode internetworking facility)
ITU International Telecommunications Union
k- kilo-
LAN local area network
LAP-B link access procedure, balanced
LAP-D 758
LAPB (same as LAP-B)
LAPD link access protocol, D channel
LAPD (same as LAP-D)
LC late counter
LC late counter
LED light-emitting diode
LF line feed
LF low frequency
LI length indicator
LIC lowest incoming channel
LLC logical link control
LNTP 588 (experimental lightweight transport protocol)
LOC lowest outgoing channel
LRC longitudinal redundancy check
LSAP logical service access point (410)
LSI large scale integration
LTC lowest two-way channel
M- mega-
m- milli-
M2M manager-to-manager
MAC medium access control
MAN metropolitan area network
MAP Manufacturing Automation Protocol
MD5 Message-Digest Algorithm
MD5 23, an authentication standard
MF medium frequency
MHS Message Handling Systems
MIB management information base
MIL-STD military standards
MIL-STD-1777 (DOD standard for IP)
MIL-STD-1778 (DOD standard for TCP)
MIL-STD-1780 (DOD standard for FTP)
MIL-STD-1781 (DOD standard for SMTP)
MIL-STD-1782 (DOD standard for Telnet)
MITREnet 368
MS message store
MTA message transfer agent
MTAE 748
MTS message transfer system
n- nano-
NAK negative acknowledgment
NAU network addressable unit
NBS 583
NIST National Institute of Standards and Technology
NRM normal response mode
NRZ nonreturn-to-zero
NRZ 54
NRZ-L nonreturn-to-zero-level
NRZI nonreturn to zero inverted
NSAP network service access point
NT 806
NT network-terminating equipment
NT1 network termination 1
NT12 network termination 1, 2
NT2 network termination 2
NUL null
OSI open systems interconnection
OSPF open shortest path first
P/F poll/final
P1 (MHS X.419 Message Transfer Protocol)
P3 (MHS X.419 Remote UA Access Protocol)
P7 (MHS X.419 MS Access protocol)
PA pre-arbitrated
PABX private automatic branch exchange
PAM pulse amplitute modulation
PBX private branch exchange
PC pacing count
PCM pulse code modulation
PDAU physical delivery access unit
PDU protocol data unit
PDY 16
PGI parameter group identifier
PI parameter identifier
PIN photodiode with a segment of intrinsic silicon between the P
and N layers
PM phase modulation
PSH push function
PSK phase shift keying
PSN packet switching nodes
PSPDN packet-switched public data network
PVC permanent virtual circuit
Q.922
QA queue arbitrated
QPSK quadrature phase-shift keying
RD request disconnect
REJ reject
RF radio frequency
RFC request for connection
RFNM request for next message
RH request/response header
RIM request initialization mode
RIP Routing Information Protocol
RJ reject
RNR receive not ready
RNR receive not ready
RQ request count
RR receive ready
RS record separator, recommended standard
RS-232-C 158
RS-422-A
RS-449 158
RSA 680
RSET reset
RST 563
RST reset the connection
RWI virtual route reset window indicator
RZ return-to-zero
S-frame supervisory frame
S/N signal-to-noise ratio
SA source address
SABM set ABM mode
SABME 410
SABME set ABM mode extended
SAP service access point
SAPI service access point identifier
SARM set ARM mode
SARME set ARM mode extended
SCB secondary clear to send
SCF secondary received line signal detector
SCMD command
SCZ 154
SD starting delimeter
SDH 415
SDLC synchronous data link control
SEL 252
SFD start frame delimeter
SHF super high frequency
SI shift in
SI SPDU identifier
SIM set initialization mode
SMI structure of management information
SMTP simple mail transfer protocol
SNA system network architecture
SNMP simple network management protocol
SNMPv2 simple network management protocol version 2
SNRM set NRM mode
SNRME set NRM mode extended
SO shift out
SOH start of heading
SONET 415
SP space
SPDU session protocol data unit
SREJ selective reject
SREQ 596
SS-user session service user
SS7 792
SSAP source service access point
SSAP 410
SSDU 609
StarLAN 354
STX start of text
SUB substitute
SWS Silly Window Syndrome
SYN synchronous/idle
SYN synchronization character
SYN synchronize the sequence numbers
T4 218
TA terminal adapter
TC 572
TCP Transmission Control Protocol
TDM time-division multiplexing
TE terminal equipment
TE1 779
TEI terminal endpoint indentifier
TELNET (provides remote login capability)
TEST test
TFTP trivial file transfer protocol
THT token holding time/timer
THT token holding time/timer
TLV type-length-value
TMS time-multiplex switching
TOP Technical and Office Protocols
TPDU transport protocol data unit
TPDU-NR send sequence number of DT TPDU
TRT token rotation time/timer
TRT token rotation time/timer
TSDU 632
TSI time-slot interchange
ttl time to live
TTRT 388
TTRT target token rotation time
TV television
TYMNET 281
U-frame unnumbered frame
UA unnumbered acknowledgement
UA unnumbered acknowledgment
UA user agent
UDP User Datagram Protocol
UHF ultra high frequency
UI unnumbered information
UI user information
UP unnumbered poll
URG urgent pointer field significant
US united separator
VBR variable bit rate
VC virtual channel
VC virtual circuit
VCC virtual channel connection
VF voice frequency
VHF very high frequency
VLSI very large scale integration
VMTP 588 (experimental lightweight transport protocol)
VPC virtual path connection
VPI virtual path identifier
VRC vertical redundancy check
VRPCI virtual route pacing count indicator
VRPRQ virtual route pacing request
VRPRS virtual route pacing response
VSAT very small aperture system
VSB vestigial sideband
VT vertical tab
VTP virtual terminal protocol
W watts
WAN wide area network
WS window size
WS-MAX maximum pacing window size
WS-MIN minimum pacing window size
X.21 327 (standard containing physical-layer specification)
X.25 as in "packet switched network"
X.400 (CCITT standard for electronic mail)
XID exchange identification
XOR exclusive-or
XTP Xpress Transfer Protocol
YR-EDTU-NR next expected ED sequence number
YR-TU-NR next expected DT sequence number
HTML version Created Sept 8, 1994
Updated
Thu Sept 8 10:21:08 1994
Created Feb 11, 1998
Updated
Thurs Feb 12 1998
(clement@cs.byu.edu)