The network video surveillance system comprises a set of components connected over the IP network. The components as well as the connection between them is called the system architecture. In theory, the architecture is the same fo different manufacturers; but in practice, differences occur due to the different ways manufacturers approach the video surveillance system. The system architecture also depends on the scale of the system installed. If the system comprises less than 50 cameras and IP devices, then, a simplified architecture is used. For systems comprising more than 100 cameras, a more complicated architecture is needed.
An IP video surveillance system comprises 4 main functions:
This is performed by surveillance cameras, referred to as the “edge” of the video surveillance system. Their basic task is to capture video and stream it over the network. Other IP devices – like access control, videophone systems, and motion detectors – connect to the system and are considered as complimentary devices.
The video streams sent by the cameras at the edge are stored in storage or recording servers. These servers connect to the network and manage the storage, retrieval, and protection of data.
Many users connect to the video surveillance system: operators, system administrators, installers etc.. These users need permission to access the system, and are assigned specific privileges. All this is done through the management server which grants permissions and privileges to users trying to access the system.
Monitoring of video footage can be done through VMS software running on a workstation, a web client, or a mobile application. The monitoring component acts as a client and connects to the management server for access and permissions, and to the storage server to fetch the video footage.
These 4 functions are necessary in every surveillance system. However, depending on the manufacturer and the size of the implementation the hardware devices that perform these functions may be different. For example, in a simple installation where the number of cameras does not exceed 50, the storage, management, and monitoring functions can be performed by a single device (e.g. NVR). For larger installations, each function can have one dedicated server – or more – depending on the level of complexity of the system.