Figure 2 shows how the same security management network can be constructed using distributed databases.
To distribute configuration data, each remote workstation can keep a local cache of the site database. Configuration data does not change very frequently. This means the information can be synchronized between the central server and the remote workstations either according to a managed schedule or on-demand when a change happens. In the event that the central server, a core LAN switch or the WAN fails, users at workstations can continue to work using their locally cached site database.
Distributing licensing data
Rather than holding license information centrally in the central server, individual components of the security management system can hold their own licenses. For example, cameras can hold information in their on-board memory about allowed viewing and recording resolutions, or allowed frame rates. They can also hold information on which features are enabled such as advanced motion analytics.
Such a model, where the sources of the valuable data (the cameras and recorders) contain their own licenses, means that the cameras and recorders never need to talk to the central server. Because the data sources have their own distributed licenses, this frees up the data viewing applications, running on each workstation, from requiring any license at all. An operator can’t view video if the camera or recorder won’t let him. This means none of the workstations need to check licensing conditions with the central server.
Distributing live data
Rather than continuously streaming recording and alarm data back from the remote sites to the central site across the WAN, it would be much better to keep the data locally on the LAN. One or more local NVRs at each remote site would reduce traffic across the WAN and allow users at the remote sites to access recordings and alarms even when the WAN is not available.
Of course the central office is often where alarm management happens across the whole security management system so users in the central office can still access the remote NVRs in the event of an alarm or incident investigation. Usually when this happens they only need to playback or export certain portions of video from certain cameras and don’t need to access the full 24x7 recordings that have been made of all cameras at the remote site.
Less than 0.1 percent of video ever gets looked at, so why waste valuable WAN bandwidth unnecessarily? Just use the WAN to restore the pertinent recorded video data when required.
System designers and end-users should ensure that when choosing an IP video platform for their security system it is based on a distributed solution, otherwise the lack of scalability may hinder future expansion and the single point of failure could lead to unreliable operation.
Before joining IndigoVision as Chief Technical Officer (CTO) in 1999, Barry Keepence worked for over 10 years in the space industry and at 3Com as a System Architect.