[Editor's Note: This series of articles will examine basic concepts that systems integrators need to comprehend when deploying video systems over a network. Articles will appear monthly on the CCTV and Integrators sections of SecurityInfoWatch.com and under the "columns" listing of IPSecurityWatch.com.]
In our previous articles, we looked at IP addressing. Now, let’s take a look at the network characteristics of IP video surveillance.
One of the things that stays true in networked video is that as the resolution increases, the tolerance to packet loss decreases dramatically. A high-definition camera at 1080P at 30 frames per second (fps) will not only increase the average load on the network by 5-6 times over standard definition IP camera at 4CIF 30 fps, it will also generate traffic bursts which are a factor of 20 times the standard definition camera.
To successfully deploy either resolution IP cameras on a existing network, the physical security integrator and the network manager must work together to assess the existing network to determine if the infrastructure is capable of handing video traffic.
Depending on the size and scope of the deployment, either a full-time project manager is required, or for smaller deployments, an existing staff member must fill this role. The project manager must work with the stakeholders to set the scope of the project, develop a timeline to complete the implementation, and create a detailed plan. Additionally, they must monitor the progress of the plan, provide relevant updates to the stakeholders, and address any risks and roadblocks to completion.
Education and Training
IP video surveillance deployments are particularly challenging because historically, the physical security manager and the network manager had little reason to interact. In IP video surveillance, the dedicated cable plant of COAX and twisted pair is replaced by LAN switches and CAT-5 cable. The physical security integrator and operations staff must have a basic knowledge of networking to communicate their needs and objective to the network manager. Security integrators have a skill set which the network engineer does not possess, but do need to supplement this with network certifications such as a Cisco Certified Network Associate Routing & Switching (CCNA). Having a Cisco Certified Internetwork Expert (CCIE) on staff is a competitive differentiator.
If an existing network infrastructure will be used for a basis of the deployment, it must be adequately documented and an inventory of the components completed. The type, model number and software/firmware releases of the switches and routers should be documented. In addition to a network topology diagram, the location and distances between IP cameras and the wiring closets must be determined. Because of the camera location requirements of video surveillance deployments, in some instances twisted pair will need to be supplemented with fiber due to distances. If in-house expertise is not available, a cabling contractor is needed.
Video traffic increases the bandwidth requirement of the network substantially over what VoIP and data require. While video collaboration applications and TelePresence also consume bandwidth, IP video surveillance is different in that it must be streamed 24x7 from camera to network digital video recorder (NDVR). Even if video is only recorded on motion or an external trigger, the images must be first transmitted to the NDVR before being trimmed and the record-on motion segments gleaned.
IP video surveillance has requirements for Network Time Protocol (NTP) services, Power-over-Ethernet , system logging (Syslog), File transfer (FTP/TFTP) servers and Simple Network Management Protocol (SNMP) trap servers. An important part of the network assessment process is to identify and access these services within the enterprise network or implement if none exist.