beautypg.com

Network > qos (quality of service) – Vivotek FE9380-HV 5MP Outdoor Network Fisheye Dome Camera with Night Vision User Manual

Page 104

background image

VIVOTEK

104 - User's Manual

Network > QoS (Quality of Service)

Quality of Service refers to a resource reservation control mechanism, which guarantees a certain quality

to different services on the network.

Quality of service guarantees are important if the network capacity

is insufficient, especially for real-time streaming multimedia applications. Quality can be defined as, for

instance, a maintained level of bit rate, low latency, no packet dropping, etc.

The following are the main benefits of a QoS-aware network:

The ability to prioritize traffic and guarantee a certain level of performance to the data flow.

The ability to control the amount of bandwidth each application may use, and thus provide higher

reliability and stability on the network.

Requirements for QoS

To utilize QoS in a network environment, the following requirements must be met:

All network switches and routers in the network must include support for QoS.

The network video devices used in the network must be QoS-enabled.

QoS models

CoS (the VLAN 802.1p model)

IEEE802.1p defines a QoS model at OSI Layer 2 (Data Link Layer), which is called CoS, Class of

Service. It adds a 3-bit value to the VLAN MAC header, which indicates the frame priority level from 0

(lowest) to 7 (highest). The

priority is set up on the network switches, which then use different queuing

disciplines to forward the packets.

Below is the setting column for CoS. Enter the

VLAN ID

of your switch (0~4095) and choose the priority

for each application (0~7).

If you assign Video the highest priority level, your network switch will handle video packets first.

• A VLAN-capable switch (802.1p) is required. Web browsing may fail if the CoS setting is incorrect.

• Class of Service technologies do not guarantee a level of service in terms of bandwidth and delivery

time; they offer a “best-effort.” Users can think of CoS as a “coarsely-grained” traffic control and QoS

as a “finely-grained” traffic control.

• Although CoS is simple to manage, it lacks scalability and does not offer end-to-end guarantees

since it is based on L2 protocol.

NOTE: