Configuring and Managing Host-Based X.25 Links - Edition 5 (36939-90054)
Glossary 215
Glossary
throughput class negotiation
One of the network subscribed
facilities defined at subscription
time. This allows the user to
negotiate the throughput class at
call set-up time.
timer (T3) Length of time that a
link can remain in an idle state.
After the expiration of the timer,
the link is considered to be in a
non-active, non-operational state
and is automatically reset. The
value should be chosen carefully.
In particular, it must be
sufficiently greater than the
retransmission timer (T1) so that
no doubt exists about the link's
state.
token ring A collection of data
communicationsystems sharing a
common cable and
communicating by means of the
IEEE 802.5 protocol. In a token
ring network, access is controlled
by the passing of a token from
node to node. Outgoing messages
are attached to the token and
passed with the token until they
arrive at the node to which they
are addressed.
Token Ring 3000/iX Network
Link Hardware and software
required to connect a HP 3000
Series 900 system to a token ring
network.
topology The physical
arrangement of nodes in a
network. Some common
topologies are bus, star, and ring.
Transmission Control
Protocol TCP. A network
protocol that establishes and
maintains connections between
nodes. TCP regulates the flow of
data, breaks messages into
smaller fragments if necessary
(and reassembles the fragments
at the destination), detectserrors,
and retransmits messages if
errors have been detected.
Transpac The national public
PSN of France.
transparent mode Data
transfer scheme in which only a
limited number of special
characters retain their meaning
and are acted on by the system.
All other characters are
considered to be data and are
passed through with no control
actions being taken.
transport, network Software
that corresponds to layers 3 and 4
of the OSI network architecture
model. The function of this
software is to send data out over
the appropriate communications
link, to receive incoming data,
and to route incoming or outgoing
data to the appropriate
destination node.
TTUTIL Also known as the
Workstation Configurator. A
program, TTUTIL.PUB.SYS, on
the HP 3000 that is used to create
and modify terminal and printer
type files.
Tymnet A proprietary public
data network in the USA.