Virtual path identifier (vpi), Vp (nominal velocity of propagation), Wan (wide area network) – Agilent Technologies J3972A User Manual
Page 179: Wide area network (wan), Yellow alarm
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Virtual Path Identifier (VPI)
The Virtual Path Identifier is an 8-bit field in the ATM header.The VPI and VCI
are used together to determine the destination address of the ATM cell.
Vp (nominal Velocity of Propagation)
The speed that a pulse travels along a given cable. Vp is expressed as a percentage
of the speed of light in a vacuum.
WAN (Wide Area Network)
A data network engineered for relatively lower speed data transfers over unlimited
distances. Often the links in a WAN are provided by a third party.
Wide Area Network (WAN)
A communications network that uses public and/or private telecommunications
facilities to link computing devices that are spread over a wide geographic area.
Yellow Alarm
The Remote Alarm Indication (RAI (Yellow)) is a 1-bit field in the Path Status
octet (G1) of a PLCP frame. An RAI value in a PLCP frame is set to 1 after an
error condition has been detected. The RAI is cleared (0) after the error condition
has not occurred for a certain period of time.