Iented, X.25, Tcp/ip – Interphase Tech 4538 User Manual
Page 148: Token ring, Sts1
Glossary
126
Interphase Corporation
STS
u
Synchronous Transport Signal
STS1
u
Synchronous Transport Signal level 1 Basic building block signal of
, operating at 51.84
Mbps. Faster SONET rates are defined as STS-n, where n is a multiple of 51.84 Mbps.
SVC
u
Switched Virtual Circuit Virtual circuit that is dynamically established on demand and is torn
down when transmission is complete. SVCs are used in situations where data transmission is sporadic. Called
a switched virtual connection in
terminology.
T1
u
-formatted data at 1.544 Mbps through the telephone-switching network, using
or
coding.
T3
u
Digital
carrier facility. T3 transmits
-formatted data at 44.736 Mbps through the telephone
switching network.
TCP
u
Transmission Control Protocol Connection-oriented transport layer protocol that provides reliable
full-duplex data transmission. TCP is part of the
protocol stack.
TCP/IP
u
Transmission Control Protocol/Internet Protocol Common name for the suite of protocols
developed by the U.S. DoD in the 1970s to support the construction of worldwide internetworks.
and
are the two best-known protocols in the suite.
TFTP
u
Trivial File Transfer Protocol Simplified version of
that allows files to be transferred from
one computer to another over a network.
Token Ring
u
Token-passing
developed and supported by IBM. Token Ring runs at 4 or 16 Mbps over
a ring topology. Similar to IEEE 802.5.
TTY
u
Teletypewriter General term for an input device.
Tx
u
Transmit or Transmitter
USRBUF
u
A driver structure describing the use of a specific buffer containing payload data to be trans-
ferred using
. They can be linked together to allow non-contiguous areas of memory to be sent as one
unit.
X.25
u
standard that defines how connections between
are maintained for remote ter-
minal access and computer communications in
s. X.25 specifies
, a data link layer protocol, and
, a network layer protocol.
has to some degree superseded X.25.
VBR
u
Forum for ATM networks. VBR is subdivided into
a Real Time (RT) class and Non-Real Time (NRT) class. VBR (RT) is used for connections in which there is
a fixed timing relationship between samples. VBR (NRT) is used for connections in which there is no fixed
timing relationship between samples, but that still need a guaranteed QoS.
VCC
u
Virtual Channel Connection Can be a Permanent Virtual Connection (
) or a Switched Virtual
Connection (
). Any
connection between two nodes.
VCI
u
Virtual Channel Identifier16-bit field in the header of an
cell. The VCI, together with the
,
is used to identify the next destination of a cell as it passes through a series of ATM switches on its way to its
destination. ATM switches use the VPI/VCI fields to identify the next network VCL that a cell needs to transit
on its way to its final destination. The function of the VCI is similar to that of the
VCL
u
Virtual Channel Link Connection between two
is made up of one or more
VCLs.
VPI
u
Virtual Path Identifier 8-bit field in the header of an
cell. The VPI, together with the
, is
used to identify the next destination of a cell as it passes through a series of ATM switches on its way to its
destination. ATM switches use the VPI/VCI fields to identify the next VCL that a cell needs to transit on its
way to its final destination. The function of the VPI is similar to that of the
in
WAN
u
Wide-Area Network Data communications network that serves users across a broad geographic
area and often uses transmission devices provided by common carriers.
, and
are
examples of WANs.