How to design a 1000 channel large-scale monitoring system
Source: https://vedard.com/blog/how-to-design-a-1000-channel-large-scale-monitoring-system
Date: 2020/11/03
How to design large-scale surveillance system? For example, how to design 1000 channel monitoring system? Today, we will discuss how to design 1000 channel video surveillance monitor system of hardware configuration.
The 1000 channel video surveillance system is a medium to large-scale security project. There are four main problems we should solve to build up the 1000 channels video surveillance system.
1.What camera is it used?
2.How to choose the switchboard? How to build up the network?
3.How to arrange storage properly?
4.How to display the 1000 monitor videos?
We will analyze one by one.
1.What camera is it used?
Generally, more than one type of camera is used in the 1000 channel surveillance solution. Different types and functions of security cameras are selected according to the application environment.
Security camera types:
A.Bullet camera: both hoisting and wall mounting are acceptable, and a protective cover is generally required for outdoor installation. Generally it is installed in the corridor, in the factory or outdoor areas such as parking lots. It is mainly used in underground warehouses, warehouses, monitoring urban roads, community outdoor area.
B.Dome camera: Actually, it is “integrated movement(zoom lens+camera) shield+PTZ+PTZ protocol decoding”. It is generally used outdoors or indoors where the area is relatively large and the scope is relatively wide.
C.Dome camera: It is ceiling installed. Mostly it is used in indoor small-scale monitoring areas without lights or relative dark including semi-public areas such as hotel corridors, hospitals, communities, elevators, indoor halls and other places.
D.Infrared integrated camera: a surveillance camera with infrared night vision probe, which can be widely used in day and night and large-scale surveillance areas, such as communities, supermarkets, squares, banks, factories, military camp schools and other places.
Suitable camera should be selected according to actual application of the security project. The cameras have different resolutions and code rate showed as below:
2.How to choose Ethernet switch?
The focus of the 1000 channel monitoring project is the choice of switches. Here we choose a three-layer network structure. The structure is the access layer-the convergence layer-the core layer. Compared with the two-layer network structure, the three-layer network structure has larger scale and longer transmission distance. The network expand ability is stronger.The topology is as follows:
I The code stream of a single camera is generally calculated at 4Mbps, and the peak value is 6-8M. The peak value should be considered when selecting the model.
II The transmission bandwidth utilization rate is about 60%, so 100M bandwidth is about 60M utilized.
Sum up the above two points, a 100M switch can generally be equipped with 8 cameras, and Gigabit up switches should be used for cameras with more than 8 channels.
According to the layout of the front-end, centralized or decentralized, switches with different port numbers from 8 to 24 may be used. According to the installation environment, industrial-grade switches may also be used.
B.The choice of aggregation layer switch
The aggregation layer is a link between the access layer and the core layer. Compared with access layer switches, higher performance, more interfaces and higher switching speeds are required. Attention points in the selection and design of the aggregation switch:
Switch Bandwidth: For the 1000 channels cameras, if the aggregation layer has 8 switches, then each need to deal with 125 cameras 4M bit stream(125 * 4M = 500M), which means aggregation layer switches need to support both forward 500Mor more Exchange capacity.Taking into account the different access equipment of the front-end switch such as 100M, Gigabit, electrical or optical ports, it is advised to choose a Gigabit photoelectric hybrid switch.
Backplane bandwidth: Each aggregation layer switch will be connected to at least 5 Gigabit switches. In order to ensure sufficient bandwidth, the switch backplane bandwidth requirement is:(5*1000M*2)/1000=10Gbps backplane bandwidth.
Packet forwarding rate: the packet forwarding rate of a 1000M port switch is 1.488Mpps/s, and the exchange rate of the switch at the aggregation layer is:5**1.488Mpps/s=7.44Mpps.
According to the above conditions: when 1000 cameras are connected to the network, the aggregation layer needs to meet the backplane bandwidth not less than 10Gbps, packet forwarding rate is greater than 7.44.
C.Selection of core switch
The core switch is mainly responsible for data forwarding and network structure setting functions, and has higher requirements for switching capabilities, network management functions, and stability. In addition, because the storage device is at the core layer, the switching capacity of the switch and the bandwidth and high-speed forwarding capability of the core link need to be considered. So the following conditions must be met:
Bandwidth: The bandwidth of 1000 channels of monitoring is at least 1000*4Mbps=4000Mbps. It is recommended that the core switch a high-bandwidth Gigabit or 10 Gigabit switch, and the uplink port is 10 Gigabit to make the data smooth.
Backplane bandwidth: The core switch will have at least 8 Gigabit ports from the aggregation layer, 2 uplink 10 Gigabit ports, and 4 possibly connected to other Gigabit ports, so there are a total of 12 Gigabit ports and 2 A 10G port, in order to ensure sufficient bandwidth, the bandwidth requirements of the switch backplane are:
(12*1000M*2+2*10000*2)/1000=64Gbps backplane bandwidth.
Packet forwarding rate: The packet forwarding rate of a gigabit port is 1.488Mpps/s, and the packet forwarding rate of a 10 megabit port is 14.88Mpps/s, in order to ensure wire-speed forwarding, there will be at least 12 Gigabit ports and 2 10 Gigabit ports, the exchange rate of the core switch is:
12*1.488Mpps/s+2*14.88Mpps/s=47.56Mpps.
According to the above conditions: when 1000 cameras are connected to the network, the core layer switch must at least meet the backplane bandwidth of not less than 64Gbps, and the packet forwarding rate must be greater than 47.56Mpps.
In addition, for the core switch, also need to consider system expand ability, number of slots, module type, module redundancy, routing redundancy, etc.
3.1000 channel monitoring storage design:IP-SAN
For the storage of 1000 channel monitoring system, NVR and hard disk alone are not enough. IP SAN storage can be used. IP SAN is a kind of SAN. It has large capacity and can connect to hundreds of videos, but the price is more expensive, so we choose IP SAN, that is, disk array+hard disk.
So, when it comes to the 1000 channels full HD IP real time monitoring, how much data will be stored? About 4Mb of 30FPS video stream of network Camera per second. Each NVR has 42 channels of real-time video streams, and 1000 channels of high-definition video streams are all transmitted to the APT dual-control 10Gb disk array, generating 4Gb of data per second.
A camera with a code rate of 4M has a storage capacity of about 48G a day. So 1000 Ge 7 storage days is: 1000 Cameras *48G*7=395136G=328T or so.
Calculated on a 4T hard disk, it shows about 3700GB on the computer, with h.265 encoding format,96 hard disks can be used, and it is enough. For this 96 drives, every 4 drives can compose a RAID5, consisting of 24 RAID groups. We use 16 bay network storage IP SAN disk array, 6 can be OK.
In addition to storage capacity, for large-scale public monitoring systems must also consider its expand ability and ease of management, so IP SAN is the most ideal solution.
4.1000 channel monitor display design
How to display 1000 channels of monitoring? Monitoring display walls are generally chosen for Large-scale monitoring projects. The monitoring center has a management platform, which needs to be equipped with a comprehensive monitoring integrated platform, which requires strong decoding capabilities and powerful functions. The number of previews on the wall depends on the specific needs. You don’t need to finish all of them, you can do rounds.
Another key point of the 1000 channel monitoring system is the allocation and setting of IP addresses.
5. conclusion
In general, the design principle of the 1000 channel video surveillance system is: based on the premise that the system is stable, reliable, and expandable, the surveillance screen is required to be free from freezing, image interruption, and security and confidentiality.
When planning and building up the network systems, should overall consider the camera streams, network bandwidth, data transmission volume, specific network environment, as well as user specific requirements of the monitoring system and other factors. At last properly make the 1000 channel surveillance design and select the appropriate monitoring equipment.