What is QoS and Why is it Important?

Quality of Service (QOS)If you already know what Quality of Service is, how it works, and why it is important, stop here and thanks for reading J. For the other 98% of the world, read on and hopefully you will have a better understanding. I promise this will not get too technical.

Quality of Service  (QoS) is most likely one of the networking concepts that is most misunderstood by management and business owners. However, it is very important for near real time business critical applications such as telepresence (video conferencing and video calls) and remote office IP Telephony (voice calls over data networks.)

First, “What is QoS?” QoS is an advanced capability of networking that allows internet/network traffic for specific applications or types of traffic to be “prioritized” over others.

What does this mean in simple terms? It means that the network traffic for a voice call can be given priority over a movie download or large file transfer as it passes through the network.

Why is this important? That is a little bit longer discussion. Do you get annoyed when you are watching a live video broadcast of a football game and it freezes during the most important play? Do you get frustrated when you are on the phone with your colleague and midway through the conversation you only hear every other word they are saying? I know it really ticks me off when those things happen. In the networking world, this is usually due to network congestion somewhere between you and the transmitting party. Most likely some tech guy is downloading a 3 gigabyte file.

So how does QoS help? In the case of the voice call where you hear every other word while that tech guy is downloading the ISO file, QoS would give priority to your phone call over the other guys file download so that you could hear every word.

The best illustration of this is the following; imagine an ambulance travelling through congestion on a freeway or local street. The highway is equivalent to your internet connection, the number of lanes is your bandwidth, the ambulance is your voice call and all the other cars are everyday activities like a file download or web page loading. As we all know, it does not matter how many lanes are on a street or highway, they can always get congested. An ambulance without lights on is given no priority in traffic, and will arrive with same delays as any other vehicle. However, the ambulance with his lights on has priority and moves ahead or past everyday vehicles to be sure they get to their destination in a timely manner. In some areas the lights will even change for the ambulance as it progresses to its destination. The lights being on is an indicator to give the ambulance priority and get out of its way. This is roughly equivalent to QoS tagging important application traffic such as your voice calls.

So how can you ensure you have QoS on your network? First you need to ensure that every leg of your connection can honor QoS. If there is a device between you and the receiver that does not honor QoS, then you don’t have QoS. Just like in the ambulance example, one red light or one car not getting out of the way of the ambulance can really muck things up and cause issues.

QoS can be easily tested with the right performance tools and traffic simulators. If you are planning to implement telepresence or Voice over IP in your business, getting a network assessment that includes traffic/network performance evaluation can prove to be beneficial. This will ensure you have enough lanes on the highway and that all of your traffic knows who has priority. It will save you immense headaches and end user complaints when you roll out video or voice over IP.

Noel-Barber-11Noel Barber is a veteran of the IT industry and serves as the Vice President of Professional Services at ABS. In addition to staying on top of industry trends and changes, Noel works to ensure ABS continuously brings the best technology solutions to our clients.