Video surveillance is widely used in modern cities, and surveillance equipment is installed in all road points and public areas. As the performance of high-definition video surveillance cameras is getting higher and higher, a series of problems such as video freezes and packet loss are often encountered in video surveillance projects. Then how to choose a suitable industrial switch according to different surveillance needs can meet the surveillance requirements. The performance requirements of the overall network of the system can achieve the purpose of reducing costs. Industrial switches are the core role of monitoring network transmission equipment. When it comes to the selection of industrial switches, you might think that there are many important parameters to consider, such as ports with a speed of 100M/Gigabit/Gigabit, electrical/optical/PoE ports, number of ports, MAC address table depth, forwarding delay , Cache size, VLAN, isolation, etc. If the industrial switch is not selected properly, it will cause various failures and problems, which will seriously affect the delivery and experience of the project. We all know that a complete monitoring network has three layers of architecture: core layer, convergence layer and access layer. So when choosing these industrial switches, what factors should be considered? The number of interfaces and speed of industrial switches are the most important indicators for selecting and monitoring industrial switches. The number of interfaces of industrial switches can be determined according to the number of access devices, and some interfaces will be reserved for subsequent expansion; in order to ensure non-blocking, no packet loss, and real-time transmission of video traffic, it is necessary to select an industrial switch with a suitable port rate, which is mainly considered The following points: 1. The bandwidth used by monitoring industrial switches is closely related to the size of the IPC code stream; 2. The peak bandwidth requirement of IPC = code stream × 120%, the stable use of IPC can be guaranteed under the peak bandwidth; 3. After the NVR adds IPC, it will fetch the main stream and sub stream of IPC at the same time; 4. The actual bandwidth of the industrial switch is recommended not to exceed 70% of the maximum port rate, that is, it is not recommended to exceed 70M bandwidth for 100M interfaces, and it is not recommended to exceed 700M bandwidth for gigabit interfaces. (Quick calculation formula: bandwidth value = (main stream + sub stream) * number of streams taken * 1.2) l Camera code stream calculation method When selecting industrial switches, we must first figure out the number of cameras and the stream of cameras. The current mainstream camera encoding technology is mainly based on H.265 technology, and the stream of a single camera = main stream + sub stream. The sub-stream is generally used for network transmission, and the main stream is used for high-definition preview and video recording of the camera. l Access industrial switch selection The access layer industrial switch is mainly to solve the access needs between adjacent users. The shared address we often use in our office is the credit of the access layer industrial switch, which allows users in the same LAN to access files under the specified path, which greatly It facilitates daily work. At the same time, in some large-scale networks, the industrial switches at the access layer also have the functions of user management and user information collection, such as user authentication, identifying user IP and so on. After knowing the code stream of the camera, we can select the industrial switch. Generally, the actual theoretical value of the actual bandwidth of an industrial switch is 50%-70%, and the actual bandwidth of a 100M interface is 50M-70M. Let's take a simple example to illustrate. With 1080P network camera 4M stream calculation, how many channels of 1080P network camera can be connected to a 100M port connected to an industrial switch? 4M*12=48M, it is recommended that a 100M access industrial switch can be connected to a maximum of 12 1080P network cameras. At the same time, considering that the current network monitoring adopts dynamic encoding, the peak value of the camera code stream may exceed 4M bandwidth, and the bandwidth redundancy design is also considered. Therefore, when a 100M access industrial switch is controlled within 8 units, it is the most suitable, and more than 8 units are recommended. Use gigabit ports. In some ultra-high-definition network monitoring systems, in order to ensure high-definition video images and high reliability of data transmission, the access layer can also directly select full gigabit industrial switches. l Convergence layer industrial switch selection From the name of the aggregation layer industrial switch, it is the aggregation part of multiple access layer industrial switches. It is used to transmit the information of the core layer industrial switch and the access layer industrial switch. The aggregation layer industrial switch can implement the strategy according to the edited program. Functions such as routing between VLANs, working group access, and address filtering. It is still calculated by the 4M code stream of 1080P network cameras. Each access layer industrial switch at the front end has 6 1080P network cameras, and the convergent industrial switch is connected to 5 access layer industrial switches. The total bandwidth of the convergence layer industrial switch is 4M*6*5=120M, so the cascade port of the convergence industrial switch and the core industrial switch should be a gigabit port. l Core layer industrial switch selection The core layer industrial switch needs to meet more conditions. As a backbone transmission network, it needs high reliability, high efficiency, manageability, low latency, and so on. It is the core of the entire HD network monitoring system. When choosing a core industrial switch, you must consider the bandwidth capacity of the entire system and how to configure the core industrial switch improperly, which will inevitably lead to the inability to display smooth video images. For large-scale monitoring projects, core industrial switches will definitely be configured. Now most of the monitoring systems directly adopt the core layer-access layer flat architecture, so the core layer industrial switch is the traffic forwarding center of the network video camera and bears a large amount of data, so it is necessary to ensure that the port of the industrial switch is not bottleneck. Therefore, the monitoring center recommends choosing a full gigabit core industrial switch. If there are many points, VLANs need to be divided, and a three-layer full gigabit core industrial switch should be selected. Large-scale surveillance systems with more than 150 cameras should consider a three-layer ten gigabit core industrial switch. Key points of industrial switch selection In summary, in the monitoring network system, the importance of industrial switches is self-evident. Hongbo Video has been committed to industrial Internet communication for nearly 10 years. Its products have been applied to many industries. It has directly or indirectly participated in countless video surveillance projects. The most used access layer, convergence layer, and core layer industrial switches are 2 light 4 electricity 2 light 8 electricity, 4 light 4 electricity 4 light 16 electricity 4 light 20 electricity, 8 light 2 electricity and so on. For detailed product information, please consult When selecting industrial switches for video surveillance in a local area network, because the main pressure is on the aggregation layer industrial switches, the aggregation layer industrial switches have to bear the pressure of monitoring and storing traffic and real-time viewing and calling monitoring. Therefore, it is very important to choose the applicable convergence industrial switch. For access to industrial switches, there is no essential difference between the 100M/Gigabit port of the camera connected to the downstream port, but the upstream must be Gigabit. Freeze Drying Machine Kassel Machinery (zhejiang) Co., Ltd. , https://www.kassel-group.com