Samsung iES4028F Management Manual page 699

Glossary
the size of each region, and prevents VLAN members from being segmented from
the rest of the group.
Network Time Protocol (NTP)
NTP provides the mechanisms to synchronize time across the network. The time
servers operate in a hierarchical-master-slave configuration in order to synchronize
local clocks within the subnet and to national time standards via wire or radio.
Out-of-Band Management
Management of the network from a station not attached to the network.
Port Authentication
See IEEE 802.1X.
Port Mirroring
A method whereby data on a target port is mirrored to a monitor port for
troubleshooting with a logic analyzer or RMON probe. This allows data on the target
port to be studied unobstructively.
Port Trunk
Defines a network link aggregation and trunking method which specifies how to
create a single high-speed logical link that combines several lower-speed physical
links.
Power over Ethernet
The IEEE 802.3af standard for providing Power over Ethernet (PoE) capabilities.
When Ethernet is passed over copper cable, two twisted pairs are used for data
transfer, and two twisted pairs are unused. With PoE, power can either be passed
over the two data pairs or over the two spare pairs.
Private VLANs
Private VLANs provide port-based security and isolation between ports within the
assigned VLAN. Data traffic on downlink ports can only be forwarded to, and from,
uplink ports.
QinQ Tunneling
QinQ is designed for service providers carrying traffic for multiple customers across
their networks. It is used to maintain customer-specific VLAN and Layer 2 protocol
configurations even when different customers use the same internal VLAN IDs.
Quality of Service (QoS)
QoS refers to the capability of a network to provide better service to selected traffic
flows using features such as data prioritization, queuing, congestion avoidance and
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