Appendix A. Glossary
A-2 ATLAS Router User Manual 61200263L1-1.2A
FECN
Forward Explicit Congestion Notification. Sent to the device receiving data from the frame relay net-
work to indicate that there is congestion in the receive direction. The receiving DTE device should
take action to slow down traffic from the remote end. Compare with BECN.
FRAD
Frame Relay Access Device. Any equipment that provides a connection between a frame relay net-
work and a LAN.
Frame Relay
A subset of the X.25 packet switching protocol that allows for efficient transmission of data by utiliz-
ing many virtual circuits on a single physical interface.
Full Status Poll
A poll that occurs each N391 polls and reports the status of each PVC. During this poll the frame relay
switch can also notify the user side of the UNI of any creation or deletion of frame relay PVCs.
G.723.1
ITU-specified voice compression algorithm.
Group of Four
The Frame Relay Consortium, composed of Cisco Systems, DEC, Nortel, and StrataCom, which
defined an interface for the UNI.
HDLC
High Level Data Link Control. A generic link-level communications protocol developed by the Inter-
national Organization for Standardization (ISO). HDLC manages synchronous code-transparent,
serial information transfers over a link connection.
IAD
Integrated Access Device. A network access device that provides many services from a single plat-
form. ATLAS is an IAD.
IARP
Inverse Address Resolution Protocol. Used for resolving the protocol address when the hardware
address is known.
ICMP
Internet Control Message Protocol. Specified in RFC-292 to provide diagnostic functions.
IP
Internet Protocol. A protocol which provides for transmitting blocks of data between hosts identified
by fixed-length addresses.
ITU-T Q.933-A (Annex A)
See Annex A.
IXC
IntereXchange Carrier. Phone companies that connect LECs.