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Ensuring Nonstop IP Surveillance with an Optimized Industrial Ethernet Network

What comes to mind when you hear the term “mission-critical infrastructure?” Depending on your experience and background, you might think of oil and gas production fields, railway station monitoring systems, power generation facilities, or highway traffic systems, to name a few. The term “mission-critical” should not be taken lightly since it is used to describe networks that, once they experience instability or transmission problems, could result in serious damage to equipment and facilities, or even injuries or loss of life. In recent years, video surveillance systems have played an increasingly important role in ensuring the reliability and safety of mission-critical infrastructures around the world.

Video Surveillance is Now Standard for Industrial Mission-Critical Infrastructures

Video surveillance systems use “images” to allow security personnel to monitor an entire facility, or even a collection of facilities, from a central location, 24 hours a day, 7 days a week, instead of hiring a large contingent of security guards to man a large number of guard stations. Surveillance systems are certainly not new, but in recent years there has been a big change in how they are implemented. A basic system might simply save all of the images onto a hard drive for future analysis when the need arises. More advanced systems, however, use intelligent cameras that support extremely sophisticated features, including the ability to recognize scene changes in critical areas (e.g., if someone leaves a backpack unattended in an airport), or identify specific types of objects. It goes without saying that a video surveillance system is already a must have standard system for any type of mission-critical facility, both for monitoring events in real time, and for providing a library of images that will be available for future analysis.

According to a 2014 IHS white paper (Video Surveillance & Storage: Opportunities at the Intersection of IT and Physical Security), the surveillance market will likely see a CAGR growth of 14.8% between 2013 and 2018. The forecast for 2018 is that the entire market will generate up to USD 25.6 billion in revenue. Network video surveillance equipment is expected to make up the bulk of the market share compared with traditional analog video surveillance equipment. For example, in 2013, the Gulf region’s largest gas production projects spent € 0.8M for camera surveillance systems alone.

Challenges of IP-Based Video Surveillance Network Design

Commercial-grade video surveillance systems are used in almost every public facility, including supermarkets, offices, and schools. But when it comes to installing a video surveillance system in a mission-critical industrial application, you need to pay special attention to the following items:

Data Transmission vs. Video Transmission

Transmitting video streams presents unique challenges that you may not need to consider with basic data transmissions. At the IP packet level, data and video use the same TCP/IP technology to ensure large scale, fast data transmission. But at the application level, video surveillance normally involves establishing and managing network access between multiple devices. For example, an NVR (Network Video Recorder) and a VMS (Video Management System) operating in different control rooms may want to save or show the same video stream at the same time, while a CMS (Central Management System) may want to display images from the same the video stream on a large LCD screen. For this kind of scenario, the IP camera would usually need to send the video streams separately. For the particular case shown below, the IP camera would be required to send three video streams over the Internet.

As the number of cameras increases, the need to transmit so many video streams over the same network will occupy a huge amount of the backbone network’s bandwidth. In order to reduce the amount of bandwidth used by all of these video streams, we normally configure video streams as “multicast” type. Multicast means that each IP camera only needs to send one video stream at a time, and uses Ethernet switches to reproduce and forward the same video stream to multiple receivers automatically. The following figures illustrate the difference in bandwidth requirements between unicast and multicast configurations. As you can see, using a multicast configuration can save an impressive amount of bandwidth for the entire network.

To further illustrate how multicast streaming can save bandwidth, an actual project used 400 HD IP cameras as well as 20 video clients. When configured for unicast based transmission, engineers found that the cameras and video clients could consume up to 46,000 Mbps. However, when configured for multicast streaming, the bandwidth consumption was reduced to only 2,000 Mbps.

Lack of Redundancy for Data Transmission

Most CCTV surveillance networks use a “star” or “daisy-chain” topology to connect and expand the number of IP cameras connected to the network. However, star topologies are not designed to recover from a single point of failure. If only one network cable gets disconnected, or one network device crashes, that single point of failure could result in the disruption of a huge number of video streams. Some designers might recommend using “port trunking” technology to aggregate multiple Ethernet ports and cables into one transmission path. In this case, if one cable is disconnected, video data will continue to be transmitted through other ports and cables. However, this design cannot prevent interruptions to data transmission due to a single node failure, as would be the case if an Ethernet switch stopped working due to a power outage in the field.

Network Management Efficiency

As your network gets bigger and bigger, you will probably want to use network management software to monitor and manage the status of your network and network equipment. Experience has shown that if you have more than 50 Ethernet switches on a single (or extended) network, you should consider using an NMS (Network Management Software), since you can save a lot of time doing network management. However, there are three features you should consider when you choose an NMS for a video surveillance network:

Real-time monitoring: How fast can the NMS receive and then display alarms from large numbers of network devices? Many enterprise NMSs use traditional “polling” methods to check the status of each network device. However, with polling, the amount of time between when an alarm is triggered and the NMS notifies security personnel will increase as you add more and more devices to your network. A good industrial grade NMS will use a “pulling” or “active” method to ensure that security personnel can receive alarms as soon as they’re triggered. In this case, instead of requiring the NMS to continually poll devices in the field, switches installed at remote parts of the network will be smart enough to sense when an alarm is generated by a nearby device, and then immediately send the alarm to the central NMS.

Visualization: When network alerts appear on your screen, how quickly can you locate the root cause? For example, when an alert is triggered, can your NMS determine if the problem is most likely due to a problem with an IP camera, a network device, or a cable? And if the problem is with a cable, how easily can you determine which port on which device it’s connected to? A well designed industrial grade NMS will be designed to make the field operator’s or maintenance engineer’s daily routine easier and more precise.

Integration: Intelligent systems rely on close system integration and message exchange to ensure that your NMS can determine if end devices (IP cameras, for example) are alive or not, and provide meaningful information to higher level central management systems in the control room. However, traditional network management systems focus on the network devices themselves (Ethernet switches and routers, for example); generally speaking, they don’t have the capability to support message exchanges or monitoring of third party devices.

Moxa Solutions for Reliable Surveillance Networks

Video surveillance can be a tremendous help at enhancing public safety and ensuring that your facilities are secure. During the chaos of an emergency, IP surveillance networks could fail to deliver as expected, and instead lose key images in a matter of seconds. Moxa provides the following products to help ensure that your surveillance network will never suffer from video loss:

  • A wide selection of 10GbE, GbE, 802.11n, and PoE+ product lines that provide the most comprehensive scalability.
  • Reliable and flexible network Turbo Ring and Turbo Chain topologies, and ultra-fast redundancy technology for video stream recovery optimization.
  • An industrial grade network management suite, called MXStudio, that supports fast network deployment and easy event tracking.

More information:

For more Moxa solutions, visit our website’s High Bandwidth Industrial Ethernet Solutions page, or download our latest white paper, Unleash Big Bandwidth for Quad-Play Networks. For more product information about Moxa’s MXstudio Network Management Software, visit the MXstudio product page.

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