Page 20 - Security Today, November 2017

BANDWIDTH CONVERGENCE
THE IP EVOLUTION Security over the network comes with challenges and accolades
By Brian Simmons
Up until about 2004, analog-based security cameras were the default choice for many enterprise and data center customers. But by 2010, IP-based cameras began to overtake those analog-based designs. The market transition occurred because of sev-
eral advantages of IP-based systems including, lower cost of ownership, one cable plant supports both and connect, control, converge and power by moving to everything IP.
All of the above-mentioned advantages mentioned are simi- lar to the adoption of VoIP technology. By using the IP network for both voice and data, the user not only eliminates the need for two disparate systems, but they also eliminate the need for two separate support teams. Additionally, like with VoIP, the IP- based video surveillance system can also be powered via Power over Ethernet (PoE) technology. This eliminates the need for a separate dedicated power circuit to support each device—a huge cost savings.
A few other advantages with IP-based systems worth men- tioning are remote access anytime, anyplace; digital images do not degrade over time; real time analytic capability; and content distributed electronically quickly and easily.
However, even with the numerous advantages that IP-based systems offer, there are some new concerns that must be account- ed for that weren’t relevant with analog-based systems. Among them is protecting the connected IP network from remote hackers located anywhere in the world who are able to gain unauthorized access to the system. A robust network security software that is continually updated to protect against new threats is a must.
Another is bandwidth capacity consumed. As the resolution of cameras continues to increase, more network bandwidth is consumed to support each camera. This also leads to an increase in the available storage capacity required. Both concerns of stor- age capacity and available network bandwidth can be eliminated with proper planning and investing in the appropriate equipment. But increasing bandwidth also demands more from the network infrastructure.
The focus of this article will be to illustrate what new HD and UHD technologies incorporated into IP surveillance video cam- eras mean to the network infrastructure. It will also discuss recom- mended solutions to support advanced video surveillance systems.
Network Bandwidth and
IP Video Surveillance
There are several factors that affect bandwidth requirements
from the network.
Resolution. The resolution of IP surveillance cameras varies
widely. There are VGA resolutions (600x480 lines of resolution) up to 8.3 MP cameras which can capture 4k video quality. The higher the resolution, the more bandwidth each camera will re- quire from the network and the greater the stress placed upon the network infrastructure.
Frame rate. The human eye cannot discern above 24 fps (frames per second) approximately. For reference, Ultra High Definition (UHD) movies are broadcast at 30 fps. Typically, in a video surveillance application, cameras are set to capture any- where between 8 fps and 20 fps depending on several factors. If the camera will be recording high speed motion, a higher frame count is needed. If the camera will be operating in low light en- vironments, a higher frame count is also needed. The higher the frames per second, the more bandwidth required.
Streaming mode. There are generally two options with today’s IP surveillance cameras. They are Constant Bit Rate (CBR) and a Variable Bit Rate (VBR). For CBR, this streaming mode streams at a constant rate. This mode is primarily used when monitoring a relatively stable environment, with limited motion and activity. Conversely, VBR is used when monitoring a highly active envi- ronment, and the bit rate increases as the activity level increases. This mode requires access to much more bandwidth during peri- ods of high activity than that of a CBR streaming mode.
Compression. Compression is done by a device or software called a CODEC (COder/DECoder or COmpression/DECom- pression). In IP video surveillance applications, the CODEC is in-
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1117 | NETWORKING SECURITY