Pr el im in a ry – ADC 500L User Manual
Page 87
PRELIMINARY
Appendix D: Glossary
Megabit Modem 500L Installation Manual
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UBR
Unspecified Bit Rate is an ATM traffic type used for LAN traffic. When network
congestion occurs, the data is stored in a buffer until it can be sent.
UDP
User Datagram Protocol is a transport protocol used to map inbound traffic (from a
remote IP address) to an internal (LAN) IP address. Uses a protocol port number for
the destination at the remote location.
upstream traffic
Communications from a user to a service provider.
VCI
Virtual Channel Identifier is a 16-bit field addressing identifier in the header of an ATM
cell used to route cell traffic. It identifies a particular VC link for a given VP.
VCMUX
Virtual Channel Multiplexer-based encapsulation used for networks with large
numbers of virtual channels making it practical to carry a single protocol per virtual
channel.
VCs
Virtual Circuits are logical connections in the ATM network over which ATM cells are
transmitted.
VPI
Virtual Path Identifier is an 8-bit field addressing identifier in the header of an ATM
cell that is used to route cell traffic. It identifies a particular VP link.
VPs
Virtual Paths are groups of VCs carried between two points. The VP provides a means
of bundling traffic traveling in the same direction. VPs are defined by a unique VPI
value.
WAN
Wide Area Network is a network consisting of nodes located across a large
geographical area. Also, the connection between a service provider and Megabit 700F
Modem.