August 05, 2013, 3:12 PM — If you've ever engaged in a voice over IP (VoIP) phone call or conducted a video conference over the Web, you've probably experienced choppy audio, pixelated video, and other "hiccups" that make these technologies frustrating to use at best and and an impediment to doing business at worst.
Those annoying interruptions are the result of data struggling to get across your network. It's important for all of the data to get from Point A to Point B, but some types--like streaming voice and video--simply won't work if the data can't travel smoothly. You can solve the problem by spending a lot of money for a bigger, faster Internet connection, but the smart way to address the issue is with QoS: Quality of Service.
QoS manages network traffic, and prioritizes certain types of data over others to ensure consistent network quality. It is generally managed at the network router or switch, to direct network traffic appropriately.
How QoS works
Data traveling across the Internet is a lot like vehicles driving across town. If five cars leave a building to drive to a restaurant, there's a mesh of roads in all directions, and there are multiple potential paths to take. Each vehicle could take an entirely different route, and the car that left first might arrive at the destination last.
There are also certain vehicles that are given priority treatment. An ambulance transporting a patient to a hospital or a fire truck racing to a house on fire is allowed to bypass standard traffic rules to ensure they reach their destination as quickly as possible because lives are in danger. It's unlikely anyone's life hangs in the balance of your streaming voice or video connection, but that same sense of urgency that occurs with emergency vehicles on the road is similar to the high priority treatment your voice and video data require.
When you transfer data from a server on the Web to a PC on your network, you might imagine that the data packets all follow each other in sequence on the same path, but that's not how it works. Data crossing the Internet has to bounce across multiple routers, and those routers determine the best possible route on a packet-by-packet basis. Like the vehicles driving to the restaurant, the packets of data in a file you download may all take different paths and arrive at your PC out of order. They're each tagged with sequence information, though, so your PC rearranges them in the proper order as they arrive.
That's fine for downloading the latest version of Firefox because you can't actually use the file until all of the packets have arrived. However, it doesn't work for streaming audio or video. When those packets arrive out of order, it introduces jitter and lag into the stream as your PC struggles to put the packets in order in real-time as the audio or video arrives.
QoS is like designating certain data as the emergency vehicles of your network: It gives higher priority to specified data to ensure it arrives at the destination in order as quickly as possible.
You can use QoS to create "express lanes" on your network for designated applications or computers, but QoS is not simply about getting the data there faster. It employs different techniques and algorithms for streaming media to make sure it arrives smoothly in the proper order to avoid interruptions, or the dreaded "buffering" message.
Prioritze voice and video traffic
There are a variety of benefits to using QoS, but it can also get complicated. Small and medium businesses should keep it as simple as possible and set up basic QoS policies for critical services and applications.
For example, if your business relies on Skype for online voice and video chat, you can designate a QoS policy that prioritizes network traffic for that service. If you have a designated PC in a conference room that is used for conducting video conferencing with clients, you can configure a QoS policy to maximize network throughput to that device.
QoS also comes in handy if you host a podcast, video tutorials, or other streaming media content from your own servers, or have files that customers might need to download. You want visitors to your business's site to have a good experience, so you should set up QoS policies that give your server a higher priority than other data or systems.
Find the right router
Most small and medium businesses rely on consumer-grade equipment and don't have dedicated IT personnel or router experts on staff to monitor and manage network performance. This presents a couple of problems: First, QoS is an advanced network management feature that doesn't exist on most consumer-grade routers, and second, proper configuration of QoS requires at least some knowledge of how networks work, and why some traffic might deserve a higher priority than others.
You can get a router or switch with QoS features by doing a little homework. Devices like the Netgear RangeMax WNDR3700 wireless router include an automated form of basic QoS. Essentially, the Netgear router is able to automatically detect audio, video, and gaming traffic, and apply different techniques to improve the quality and stability of the data transfer.
There are also devices like the Linksys E2500 wireless router, which are equipped with basic QoS features. Hidden under Applications & Gaming in the Web-based management console are settings for QoS. You can designate applications, games, or the MAC address of specific servers or PCs to be handled as a higher priority than standard network traffic. You can also use the QoS settings to assign a lower priority to data or systems that aren't as important to make sure they don't interfere with other traffic.
If you're feeling more adventurous, you can try DD-WRT. DD-WRT is a firmware update that's available as a free download. It can be installed in place of a manufacturer's firmware on a wireless router and includes functionality that may be missing--like QoS features.
A word of caution, though: You have to be careful using something like WW-DRT. It's easy to mess up the configuration and disable the router entirely or make it impossible to log back in and fix it without doing a complete reset. You also won't be able to rely on the product manual or contact the router manufacturer for technical support, so make sure you know what you're doing.
Reap the benefits of a streamlined network
Keep in mind that QoS is not a "silver bullet" that will magically make all of your network traffic flow smoothly all the time. When you're uploading or downloading data over the Internet, that traffic has to traverse a number of networks, routers, and switches to get where it's going, and you don't have any control over what happens to the data outside of your own network.
That said, employing QoS at the edge of your network can ensure that the right servers, applications, or services are treated with a higher priority, and help make certain your video conference with an important client isn't interrupted by a co-worker streaming his Spotify playlist.