Specifications

Polling
See Multidrop.
Port
The physical interface to a computer or multiplexer, for connection
of terminals and modems.
Protocol
A formal set of conventions governing the formatting and relative
timing of message exchange between two communicating
systems.
Serial Transmission
A common mode of transmission, where the character bits are
sent sequentially one at a time instead of in parallel.
Single Mode
Describing an optical wave-guide or fiber that is designed to
propagate light of only a single wavelength (typically 5-10 microns
in diameter).
Space
In telecommunications, the absence of a signal. Equivalent to a
binary 0.
Sync
See Synchronous Transmission.
Synchronous
Transmission
Transmission in which data bits are sent at a fixed rate, with the
transmitter and receiver synchronized.
T1
A digital transmission link with a capacity of 1.544 Mbps used in
North America. Typically channelized into 24 DS0s, each capable of
carrying a single voice conversation or data stream. Uses two pairs
of twisted pair wires.
T3
A digital transmission link with a capacity of 45 Mbps, or 28 T1
lines.
Telnet
The virtual terminal protocol in the Internet suite of protocols. It
lets users on one host access another host and work as terminal
users of that remote host. Instead of dialing into the computer,
the user connects to it over the Internet using Telnet. When
issuing a Telnet session, it connects to the Telnet host and logs in.
The connection enables the user to work with the remote machine
as though a terminal was connected to it.
VLAN-Aware
A device that is doing the Layer 2 bridging according to the VLAN
tag in addition to the standard bridging parameters. A VLAN-aware
device will not strip or add any VLAN header.
VLAN Stacking
A technique that lets carriers offer multiple virtual LANs over a
single circuit. In essence, the carrier creates an Ethernet virtual
private network to tunnel customer VLANs across its WAN; this
helps avoid name conflicts among customers of service providers
who connect to the carrier. Stacking works by assigning two VLAN
IDs to each frame header. One is a "backbone" VLAN ID used by
the service provider; the other one has up to 4,096 unique 802.1Q
VLAN tags.