User manual
48
Appendix 1 Glossary table
Glossary
Description
A
ARP (Address Resolution
Protocol)
An IP address to physical address protocol
Auto-Negotiation
Switches at both ends of the device in accordance with the maximum
performance to auto-negotiate the speed and duplex mode
B
Broadcast Storm
A port send excessive broadcast frame meantime on the network,
accumulate the respond to send messages on the network ,
consume
too much network resources or cause the network timeout
Broadcasting
A forwarding way send data to all branch of network
C
CoS
（
Class of Service
）
namely 802.1p priority program, CoS offer a way
for data packets to join priority tag, classify packets
into 8 level with the value 0~7 range
D
DHCP
（
Dynamic Host
Configuration Protocol
）
Information for the network to assign dynamically IP address, subnet
mask and gateway
DSCP
（
DiffServe Code
Point
）
Packaged in IP packet header of 6 bit domain, can classify packets
into 64 level with the value 0~63 range
E
Ethernet
Ethernet uses a bus or star-shaped topology and supports transmission
rates up to 10Mbps orders of magnitude. A new version called fast
Ethernet speeds of up to 100Mbps
F
Flow Control
Flow control allows low-rate devices communicate
with high-rate, the flow control can match high rate
port contracting speed with low rate port reception
speed according to the way of high rate port pause
contract
Frame
Packets contain the header and tail message of physical media layer
Full-Duplex
Receive and send data in progress at one moment meantime on
IEEE802.3x standard
H
Half-Duplex
Receive or send data in one direction at one moment in progress on
Backpressure standard.
I
IGMP
（
Internet Group
Management Protocol
）
Define the mechanism among hosts and three layers
multicast device to establish and maintain the
relationship between multicast group members.
IEEE 802.1p
Add the priority network traffic on MAC sub layer of data link layer.
IEEE 802.1q
Define the VLAN bridge operation
。
To manage ,define and operate
VLAN on the bridge LAN
Q
QoSQuality of Service
）
A technology to resolve the network delay and block problems and so
on.
T
Trunking
To make an aggregated group tied up a group of ports together to
increase bandwidth and improve the connection reliability.
ToS
（
Type of Service
）
Packaged in IP packet header of 8 bit domain to perform the different
priority packets
U
UDP
（
User Datagram
Protocol
）
Face to disconnected unreliable transmission layer protocol
UTP(Unshielded Twisted
Pair)
Not shielded media out of twisted pair
