I have been wanting to write about this for a while now.  A distributed surveillance network is simply when you have your recording servers distributed across multiple geographic locations instead of having one central recording locaiton. 

Benefits of a distributed environement:

• Ability to record remote cameras in real time, no delay
• Massive reduction of WAN usage becuase only video streams that are being viewed are pulled from the remote server
• Redundancy: If the WAN link goes down remote server keeps recording
• Redundancy: If one server in the network fails all others continue recording so you have minimal loss
• Massive increase in performance:  No one network is saturated.  Resources are shared amongst seperate physical networks and hardware devices.
• Allows for the monitoring of the geographically diverse cameras from a single location without heavy taxation of internet resources

What's it looks like?

Notice that the remote client can be anywhere in the world and only pulls the streams from the servers it needs.  Also note that this architecture is quite theoretical but some manufacturers Milestone and ONSSI look almost exactly like this.  Other manufacturers such as Genetec require the use of other hardware device to make this work properly.

I tried to make this quite simple so if you have questions please feel free to comment.  Thanks for reading!

- Ronen Isaac Continental Computers & WLANmall Video Surveillance