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Cisco Video Surveillance 8020/8030 IP Camera Reference Guide
Chapter 5 Configuration
Network > QoS (Quality of Service)
The Multicast metadata port is utilized by VADP modules to transfer video analytics results, PTZ
stream, textual data, and event messages between the camera and the client side running and
observing the video analysis. If your client side computer is located outside the local network, you
may need to open the associated TCP port on routers and firewall.
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.
In 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 level, the switch will handle video packets first.
Note
•
A VLAN Switch (802.1p) is required. Web browsing may fail if the CoS setting is incorrect.
•
The Class of Service technologies do not guarantee a level of service in terms of bandwidth and
delivery time; they offer a “best-effort.” You can think of CoS as “coarsely-grained” traffic control
and QoS as “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.
