Making IP Networks Possible

Ancillary applications make solutions run with ease

• By Bradford Beale
• Aug 01, 2010

Shortly after 6 p.m. on Sept. 28, 2009, two gunmen entered Avi Pawn and Jewelry in the Minneapolis suburb of Richfield. After stealing a small sum of money, one of the criminals fired a single shot that grazed the store clerk and fatally wounded a customer.

The local news usually supplements these stories with grainy, off-center pictures of the crime captured from store surveillance cameras. But when local television stations broke the news that evening, the images were startlingly clear. It took less than two days for the public to identify the men involved in the murder. After viewing footage from other local surveillance cameras, the police identified the getaway car and took a third accomplice into custody.

Behind the Scenes
Do not be quick to give the surveillance camera all the credit in this story though. Instead, think of it as a security system’s endpoint. At the center of the operation, PoE switches make the entire network of IP cameras and wireless access points possible -- whether in a single retail shop, in an airport or within a traffic and control infrastructure for an entire city.

These small devices transfer electrical power and data to remote devices, such as cameras, wireless access points and other network equipment. PoE switches en-able users to place devices in the optimum location -- a camera placed on top of a building overlooking a parking lot, for instance -- versus mounting the device close to an available power source.

The PoE Plus switch delivers both power and communication. Advanced managed switches have the ability to diagnose problems and power and restart cameras and other devices and sensors. Data captured by these powered endpoint devices can be quickly and safely transported across the network for real-time monitoring, DVR storage or processing.

Power-hungry
PoE switches are being adopted in a wide variety of applications and rapidly replacing traditional CCTV cameras -- promoting safety through the control and reliability they provide. In fact, the IP video camera market is evolving to higher standards of control and features at a rapid pace. The increased benefits of cameras that can pan, zoom, tilt and withstand extremely hot and cold environments come at a price: power requirements that exceed the delivery capabilities of most switches. PoE switches capable of powering these emerging camera technologies comply with the new IEEE802.3at PoE Plus standard that requires that each port provide at least 25.5 watts of power.

In the past, when a camera failed, it meant sending a service technician to the device’s location to troubleshoot; however, managed PoE Plus switches can be controlled and managed remotely. This reduces the need for costly service calls and unplanned system downtime while providing tools for remotely diagnosing problems with connected devices. Tasks like configuring ports and power cycling a non-responsive device can be managed via SNMP, command line interface, Web interface or management software.

Always On
When combined with monitoring software, managed PoE switch applications create increased levels of safety. Departments of transportation use special software in combination with roadway monitoring devices to quickly detect accidents and deploy emergency responses. Lives are at stake, so quickly restarting downed devices and ensuring network reliability is critical.

PoE Plus switches use redundant power features to increase reliability. If the power source goes out, the switch can recognize the failure and recover in just a fraction of a second with no network interruption or loss of data. The switch can further alert managers of problems through e-mail event notification and trigger a built-in relay that notifies on-site personnel of problems by flashing lights or sounding alarms.

Green scheduling -- the ability to turn off unused devices to conserve energy -- also can be managed with a PoE Plus switch. For instance, businesses that have multiple cameras focused on entrances during business hours often want to shut off some of the cameras when the business closes and the nighttime security system is turned on.

Reliability also is critical for PoE switch applications. Dependence on these devices means that they must be a rock-solid solution. This means operating in subzero temperatures, where climate extremes typically challenge the performance of networking equipment.

End users want hardened equipment that can perform around the clock -- even in extreme weather.

As crimes like the robbery mentioned at the beginning of this article continue to be rapidly solved -- or even prevented, thanks to advances in IP security technology -- demands for PoE switch applications will continue to grow. The scope of the network also will continue to expand, as they help provide safety, reliability and control for entire cities and transportation infrastructures.