User's Manual

FT-512 Trailblazer Installation and User Manual version 1.08 51
See data service unit.
DSU loopback
A Telco initiated test which loops the DSU back to the Telco and is used to test the
DDS circuit as well as the DSU/CSU.
DTE
data terminal equipment. The end-user terminal or computer that plugs into the
termination point (DCE) of a communications circuit. The main difference
between the DCE and the DTE is that pins two and three are reversed.
end device
The ultimate source or destination of data flowing through a frame relay net-work
sometimes referred to as DTE. As a source device, it sends data to an inter-face
device for encapsulation in a frame relay frame. As a destination device, it
receives de-encapsulated data (i.e., the frame relay frame is stripped off, leaving
only the user's data) from the interface device.
encapsulation
A process by which an interface device places an end device's protocol-specific
frames inside a frame rely frame. The network accepts only frames formatted
specifically for frame relay; therefore interface devices acting as interfaces to a
frame relay network must perform encapsulation. See also interface device and
frame-relay-capable interface device.
file server
In the context of frame relay network supporting LAN-to-LAN communications,
a device connecting a series of workstations within a given LAN. The device per-
forms error recover and flow control functions as well as end-to-end
acknowledgment of data during data transfer, thereby significantly reducing
overhead within the frame relay network.
gateway
A device which enables information to be exchanged between two dissimilar
systems or networks.
high level data link control (HDLC)
A generic link-level communications protocol developed by the International
Organization for Standardization (ISO). HDLC manages synchronous code-
transparent, serial information transfer over a link connection. See also
synchronous data link control (SDLC).
host computer
The primary or controlling computer in a multiple computer operation.
in-band
Signaling (dialing, diagnostics, management, configuration, etc.) over the same
channel used for data.
ingress
Frame relay frames leaving from an access device in a direction toward the
frame relay network.
interface device
Provides the interface between the end device(s) and a frame relay network by
encapsulating the user's native protocol in frame relay frames and sending the