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Glossary

Thicknet

Also called 10Base5. Bus network that uses a thick cable and

runs Ethernet up to 500 meters.

Thinnet

Also called 10Base2. Bus network that uses a thin coax cable and

runs Ethernet media access up to 185 meters.

token

A frame containing only control information. Possessing this con-

trol information gives a network device permission to transmit data onto the
network. See also: token passing.

token bus

LAN architecture that is the basis for the IEEE 802.4 LAN speci-

fication and employs token passing access over a bus topology. See also: IEEE.

token passing

A method used by network devices to access the physical

medium in a systematic way based on possession of a small frame called a
token. See also: token.

Token Ring

IBM's token-passing LAN technology. It runs at 4Mbps or

16Mbps over a ring topology. Defined formally by IEEE 802.5. See also: ring
topology and token passing.

toll network

WAN network that uses the Public Switched Telephone Net-

work (PSTN) to send packets.

trace

IP command used to trace the path a packet takes through an inter-

network.

traffic shaping

Used on Frame Relay networks to provide priorities

of data.

transparent bridging

The bridging scheme used in Ethernet and IEEE

802.3 networks, it passes frames along one hop at a time, using bridging
information stored in tables that associate end-node MAC addresses within
bridge ports. This type of bridging is considered transparent because the
source node does not know it has been bridged, because the destination
frames are sent directly to the end node. Contrast with: SRB.

transport layer

Layer 4 of the OSI reference model, used for reliable com-

munication between end nodes over the network. The transport layer pro-
vides mechanisms used for establishing, maintaining, and terminating virtual
circuits, transport fault detection and recovery, and controlling the flow of
information. See also: application layer, data link layer, network layer, phys-
ical layer, presentation layer, and session layer.

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