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custom queuing
Used by Cisco router IOS to provide a queuing method
to slower serial links. Custom queuing allows an administrator to configure
the type of traffic that will have priority over the link.
cut-through frame switching
A frame-switching technique that flows
data through a switch so that the leading edge exits the switch at the output
port before the packet finishes entering the input port. Frames will be read,
processed, and forwarded by devices that use cut-through switching as soon
as the destination address of the frame is confirmed and the outgoing port is
data compression
See: compression.
data direct VCC
A bidirectional point-to-point virtual control connection
(VCC) set up between two LECs in ATM and one of three data connections
defined by Phase 1 LAN Emulation. Because data direct VCCs do not guar-
antee QoS, they are generally reserved for UBR and ABR connections.
Compare with: control distribute VCC and control direct VCC.
data encapsulation
The process in which the information in a protocol is
wrapped, or contained, in the data section of another protocol. In the OSI
Reference Model, each layer encapsulates the layer immediately above it as
the data flows down the protocol stack.
data frame
Protocol Data Unit encapsulation at the Data Link layer of the
OSI Reference Model. Encapsulates packets from the Network layer and
prepares the data for transmission on a network medium.
A logical collection of information transmitted as a Network
layer unit over a medium without a previously established virtual circuit. IP
datagrams have become the primary information unit of the Internet. At var-
ious layers of the OSI Reference Model, the terms cell, frame, message,
and segment also define these logical information groupings.
data link control layer
Layer 2 of the SNA architectural model, it is
responsible for the transmission of data over a given physical link and com-
pares somewhat to the Data Link layer of the OSI model.
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