The national standard GB/T28181 is a communication protocol specially designed for video surveillance networking in the public security sector. Drawing on the strengths of the SIP protocol and incorporating the special purposes and functional characteristics of the surveillance industry, it establishes an improved networking and information sharing framework.

Within the protocol design of GB/T28181, the most critical element is the 20‑digit national standard ID. For large‑scale networking in public security scenarios, the standard stipulates that all devices across the entire video surveillance network shall be uniquely identified by a 20‑digit national standard ID. As the application advantages of GB/T28181 become increasingly prominent, its scope of use has expanded from public security to many other industries. In these other sectors, the number of video surveillance devices is relatively small, and national standard IDs are often assigned casually. However, various issues have emerged in practical projects, frequently caused by arbitrary ID configuration.

So how is the 20‑digit ID defined under GB/T28181, and what common problems may arise?

To understand the 20‑digit national standard ID, we can split it into the first 10 digits and the last 10 digits.

For the first 10 digits: The first 8 digits serve as the central code.

• Digits 1–2: provincial code
• Digits 3–4: municipal code
• Digits 5–6: district/county code

• Digits 7–8: grassroots access unit code

  
  

In other words, the region where a surveillance device is deployed can be identified from the first 8 digits of its national standard ID.

Digits 9–10 of the first 10 digits represent the industry code, which identifies the industry the camera belongs to. For example, code 11 for digits 9–10 stands for the education sector. Surveillance cameras installed in schools may be configured with 11 in these two positions to facilitate system maintenance and management.

The first 10 digits are not subject to strict requirements for non‑public‑security applications. Since most national standard platforms in other industries operate as internal systems, mismatches between the filled‑in codes and actual geographic information generally do not trigger major failures. Nevertheless, configuration in compliance with the standard is still recommended. Specific administrative division codes shall follow GB/T2260‑2007.

In most national standard surveillance networking projects, faults tend to occur at digits 11, 12 and 13 of the 20‑digit ID. These three digits indicate the device type of the surveillance equipment on the national standard platform.

A surveillance network includes not only cameras but also many other devices: encoders, decoders, NVRs, access control and alarm units, speakers, audio pickups, as well as numerous servers, gateways and platforms.

Examples of device type codes:

• IP camera: 132
• Network video recorder (NVR): 118
• Alarm controller: 117
• Audio input device: 136
• Audio output device: 137

Take the national standard ID 11010101911328000004 as an example. Digits 11–13 are 132, indicating that this device is a camera.

If the code is arbitrarily set to 118, the platform will recognize it as an NVR, which is highly likely to trigger logical recognition errors during operation.

Moreover, for some cameras with stringent validation rules, failure to configure the device type parameter in accordance with the national standard may result in inability to submit configuration data.

Therefore, in the configuration menu of many cameras, parameters such as video channel ID, audio output channel ID and alarm ID must be strictly configured following specifications. Otherwise, configuration submission may fail. Even if submission succeeds, it will cause confusion on the platform side.

The 14th digit of the national standard ID denotes the network identifier code. In the above example ID 11010101911328000004, the 14th digit is 8, which represents the social resource access network.

The final 15th to 20th digits are freely assignable serial numbers for cameras and other devices. In practical deployment, any combination is acceptable as long as duplicates are avoided.

For industrial applications of the 20‑digit national standard ID, configuration in accordance with standard rules is strongly advised. This greatly facilitates future maintenance and system upgrades. Especially for large‑scale multi‑site interconnected projects, ID allocation planning must be completed in advance.

The Sizai Technology video access gateway is engineered for comprehensive network access capabilities. Besides accessing national‑standard video surveillance devices, NVRs and surveillance platforms, it integrates video resources including IP intercom, video phones, network speakers, recorders and drones. It enables non‑national‑standard devices to output GB/T28181‑compliant streams and delivers rich functionalities for video convergence projects.