Eye on the Networks

Because of the mission-critical nature of their data, public safety organizations require additional eyes on their network functionality and security

• By Marty Lamb
• Mar 01, 2017

Fast, resilient wireless networks are ideal for public safety operations requiring real-time data, like surveillance video streams—but as with any technology used for mission-critical applications, there must be a way to ensure the network always functions.

In any network, changes in performance can creep up over time without detection, until one day a threshold is crossed and suddenly the network is not functioning properly. Manually tracking down an issue can be complicated; sometimes the cause of the problem is something that happened a long time ago, or is an aggregate of smaller problems that individually are innocuous, but create performance issues when combined.

Wireless Network Challenges

A wireless network may start to behave differently if a new device or piece of equipment joins the network and creates extra traffic. Another source of excessive traffic is traffic “leakage” from a wired network, where packets not meant to be on the wireless network end up there anyway.

Additionally, a user may be unaware that adding a certain application to a network would affect it, and so would not think to “unplug” it or adjust settings to set things straight. RFID readers and video equipment are examples of benign tools that can create radio frequency interference on a network without even joining the network.

So that is where a monitoring and diagnostic system can help: By providing a running baseline of how a network is functioning currently, as well as how it has been functioning over time, these types of tools can detect—and head off—any issues with a public safety organization’s wireless network.

If a network starts having issues (for example, if surveillance videos are pixelated, voice traffic is choppy, or data transfers take longer), a user can pull up the monitoring tool’s graphical interface, determine the time something changed and begin to troubleshoot why it changed. This is much easier than having to go through each part of the network individually to find problem areas.

In addition to network performance issues, there are security risks associated with wireless networks that monitoring tools can help to detect.

Security Threats to a Wireless Network

Wireless networks as a whole are naturally more vulnerable to attack than wired networks due to connectivity through the air, including:

“Man-in-the-middle” Attacks. A hostile adversary takes control of a communication link between legitimate parties and makes them believe they are communicating with one another, when in fact the hacker controls the link.

“Denial-of-service” Attacks. Even though hackers cannot spy on the network or inject their own data, they can put up enough interference that authorized users are unable to access their own network.

Packet injection Attacks. A hacker inserts data packets into a network, often impersonating another device.

Replay Attacks. Attackers can sniff packets (even encrypted ones) and replay them into the air, even if they have not defeated the encryption and have no idea what the packet contents are.

These types of security threats are particularly unsettling in a public safety context, where robust, reliable and secure communications are essential for crime detection and prevention. While monitoring and diagnostic tools cannot prevent these types of attacks, they do help ensure networks are not tampered with and that all applications are running smoothly—but not all monitoring systems are created equal.

Monitoring Tool Challenges

Public safety networks sometimes run highbandwidth operations such as surveillance video or identification software (for faces or license plates, for example) on the same network as their monitoring tools—meaning there is a large amount of data constantly coming and going on the same network.

On wired networks, this is not an issue, but some wireless networks do not have the capability to send or receive information on a single radio in full duplex; data cannot be coming in while it also is going out.

If a network is using an active monitoring system, in which the system has to individually poll every single radio on the network and receive separate confirmation from each one that it is working, important data streams could be interrupted. Video is the most affected data in public safety networks; if wireless networks and/or monitoring tools are not engineered correctly, an organization risks missed or lost frames due to these interruptions.

Because of these concerns, public safety officials need to be savvy about how what they use to monitor their network.

What to Look For

A monitoring and diagnostic tool will provide the maximum benefit to a public safety operation if it has the following attributes:

Low bandwidth. The bandwidth in a wireless network is precious, and administration tools should not significantly add to or overwhelm it. A tool should be able provide real-time monitoring information while not impacting the network itself by adding too much traffic.

Passive. In a passive monitoring system, monitored devices tell the monitoring system when something of interest happens or changescompared with an active monitoring system, in which nodes each wait to be asked (polled) whether anything has changed, creating possible delays if data is flowing in and out at the same time.

Customizable. No public safety operation is exactly the same, meaning each organization should be able to choose what information a monitoring and diagnostic tool looks for. For example, a monitoring and diagnostic tool can be used to measure the internal temperatures of each individual radio to ensure they are not overheating or freezing. This is important information for radios in a desert or arctic climate, but not for those in temperate climates.

Each individual operation should be able to choose what to monitor, so that the tool focuses on only what is most important. More importantly, the amounts and types of traffic on the network that are “normal” will vary greatly between environments. One network’s “perfect” is another’s “overloaded” or “suspicious.”

Intuitive. While an organization should not need a dedicated IT professional assigned solely to monitoring, monitoring tools still require IT and RF knowledge as well as training on the tool itself.

However, with the right tool, even a non-technically inclined employee can recognize when a network is having issues. For example, on a police force, a dispatcher might perform his or her standard job duties while also keeping an eye on a monitoring and diagnostic graphical interface on a display. If something on the interface lights up red, the dispatcher easily see that there is an issue with the network, and can alert the trained IT experts, who can begin to troubleshoot.

Web based. Related to the last point is the need for a tool that runs on a web-based server. IT departments may be stationed in a different area than a headquarters to ensure server redundancy, or because one IT department services several units. If a monitoring tool is web based, an IT engineer can view the interface over a secure web portal and begin troubleshooting any problems without having to physically be in the same room as the tool, and without having specialized software installed locally.

Data inclusive. A monitoring tool must keep an eye on what is happening in real time—no doubt about that—but it should also keep track of a network’s historical performance, allowing admins to go back in time to figure out when a problem began occurring and what might have triggered it. This helps find and diagnose any problems that have been building up over time on the network, letting admins solve issues before they impact critical operations like video surveillance.

Comprehensive. A monitoring and diagnostic tool must provide reporting on all types of network data traffic and RF interference.

An Eye on the Future of Public Safety

Public safety organizations strive to keep their citizens safe, aided by mission-critical data flowing through their networks. A monitoring and diagnostic tool can achieve this goal by ensuring that all applications stay up and running, creating a safer future for a municipality’s most important asset: its people.

This article originally appeared in the March 2017 issue of Security Today.