How to Enforce QoS While Working on SDN
How to Enforce QoS While Working on SDN
Shouldn't software-defined networking be the mainstay by now? Well, even as we continue to get closer, we take a look at how to make QoS work for you.
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For every new technology, there’s that initial excitement that makes you think “this is the innovation that will break the Gartner Hype Cycle.” But time and time again, there’s a gap between innovation hype and practical implementation.
There’s no better example of this gap than the case of software-defined networking (SDN). The concept has been around since the mid-1990s, but 2013 was when everyone thought SDN would take the world by storm. And here we are — 2017 and SDN still hasn’t become the norm.
However, we’re inching closer and closer to practical SDN, and there are plenty of reasons for IT leaders to be excited, especially with the rise of distributed enterprises and growing number of remote locations.
Among the many benefits of a software-defined network is dynamic quality of service (QoS) enforcement. That’s a nice idea, but what are you supposed to do in the meantime?
You Can’t Just Sit Back and Wait for SDN
Software-defined networking is going to change the way you approach QoS policy enforcement. By separating the control and data planes in the network, SDN will allow IT teams to shape and prioritize traffic in ways that aren’t possible with manual processes.
Typically with today’s technology, you would anticipate the necessary bandwidth for voice and video calls at a remote location and set a threshold for call volume with manual QoS policies. But with call admission control (CAC), you could end up denying calls when bandwidth is stretched thin. Using a modern app like Skype for Business, for example, means you have to make sure bandwidth is allocated properly for good call quality.
Dynamic QoS through software-defined networking will introduce new flexibility and agility to normally static policies. Rather than sinking time into manual QoS policy enforcement, SDN helps automate the process as it intelligently prioritizes traffic.
This all sounds great, but you can’t just pick up the phone and have SDN ready to go the next day. Dynamic QoS is coming, but you need to update your enforcement processes now for the best end-user experience.
Get More Out of Manual QoS Enforcement
If manual QoS enforcement is the reality you have to deal with, you might as well make it easier on yourself.
There have always been two main objectives when setting a QoS policy map — establish the proper queues and then make sure policies are enforced from end to end. These tasks can be easier said than done, but the following traffic priority settings using DSCP should give a solid foundation for your QoS queues:
- Scavenger traffic, DSCP 8: Traffic in this category will receive low priority over the network. When you have applications that provide little or no value to the business or employee productivity, DSCP 8 makes sure they don’t consume mission-critical bandwidth.
- Best effort traffic, DSCP 0: This is the default setting in most QoS policy maps. You don’t assign priority applications to this setting, but once guaranteed bandwidth is allocated, the remaining pool is left for these processes.
- Expedited forwarding, DSCP 46: These are your mission-critical applications. You guarantee a certain amount of bandwidth for apps like Salesforce, NetSuite, and data backup to ensure end-user experience doesn’t suffer and productivity stays on track.
- Operations, administration, and management (OAM) Traffic, DSCP 16: As the name suggests, these applications require guaranteed bandwidth to allow network support and maintenance. They aren’t mission-critical applications, but you still need to make sure packets aren’t dropped and that the processes are always available.
- Signaling traffic, DSCP 24: Because communications traffic is so important, it gets its own priority setting. Make sure IP voice and video telephony have enough bandwidth guaranteed to make sure the business stays up and running.
There are plenty of other priority settings to work with, but the main point is that you need to properly identify which applications belong in which category. If you’re dealing with shadow IT and unknown bandwidth needs, it will be next to impossible to manage QoS enforcement.
SDN is on its way to ease the QoS burden, but that doesn’t mean you can ignore it in the meantime. Guaranteeing a great end-user experience for all remote employees means having the right technology in place.
Published at DZone with permission of Joe Michalowski , DZone MVB. See the original article here.
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