Signamax Managed Hardened PoE Industrial DIN-rail Mount Switch - Manual (Page 30)

6 QoS
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6 QoS
In data communications, Quality of Service (QoS) is the ability of a network to provide
differentiated service guarantees for diversified traffic in terms of bandwidth, delay, jitter, and
drop rate.
On traditional IP networks, devices treat all packets equally and handle them using the first in
first out (FIFO) policy. All packets share the resources of the network and devices. How many
resources the packets can obtain completely depends on the time they arrive. This service is
called best-effort. It delivers packets to their destinations as possibly as it can, without any
guarantee for delay, jitter, packet loss ratio, reliability and so on.
The Internet has been growing along with the fast development of networking technologies.
More and more users take the Internet as their data transmission platform to implement
various applications. Besides traditional applications such as WWW, e-mail and FTP, network
users are experiencing new services, such as tele-education, telemedicine, video telephone,
video conference and Video-on-Demand (VoD). The enterprise users expect to connect their
regional branches together through VPN technologies to carry out operational applications,
for instance, to access the database of the company or to monitor remote devices through
Telnet. These new applications have one thing in common, that is, they all have special
requirements for bandwidth, delay, and jitter. For instance, videoconference and VoD need
large bandwidth, low delay and jitter. As for mission-critical applications, such as transactions
and Telnet, they may not require large bandwidth but do require low delay and preferential
service during congestion.
6.1 QoS Configuration
6.1.1 General Priority
Enable or disable the priority of the switch.
6.1.2 Port QoS Configuration
This tab page sets QoS parameters of each port. For a selected port, set the 802.1P,
Port-based Priority with DSCP enabled or disabled, the Default Priority can be set from 0 to 7.
802.1P：Enable or disable 802.1P. 802.1p priority lies in Layer 2 packet headers and is
applicable to occasions where the Layer 3 packet header does not need analysis but QoS
must be assured at Layer 2.