Category Archives: IP Video

Why Video and Voice over IP Require Special Attention On Your Network

One key difference between IP data and voice or video over IP (VoIP) is that with data the amount you can dump on your network seems limitless. Sure, the more data you dump, the slower the overall response will be for your users, but the degradation is linear and oftentimes goes entirely unnoticed, especially if the data dump is short-lived. This is certainly not the case for VoIP. In the case of VoIP, the addition of one call can bring down the quality for all the calls on the system; the same can be said with the addition of streaming just one more video.

Why? Voice and video data are very time sensitive and have latency thresholds. When you reach the latency thresholds, the real-time nature of the data renders the delayed data essentially useless. If the data does end up arriving, once it is too late to insert it back into the correct order in the data stream the data will just be dropped and the quality of the video or voice stream will be degraded. Even if all your calls and videos have been working fine, adding just one more call can ruin them all by tipping the latency budget for your VoIP QoS queue, which services all of your VoIP traffic, over the edge.

As companies incorporate more voice and video over IP technologies on their network and employees stream more videos for entertainment, it is important to have a full understanding of the pervasiveness of video and voice on the network. A recent report by Cisco revealed that in 2010 global Internet video traffic surpassed global peer-to-peer traffic, and Internet video to TVs tripled in 2010 and will increase 17 – fold by 2015. (To read the full white paper, check out this link.)

We’ve covered in detail some of the challenges of delivering video over IP in our post IP Video – It’s like Living with a Teenager, but one other element of video that causes a challenge is the need to have it work in tandem with voice. It’s not just a video signal, but a highly correlated voice signal that goes along with it. Thus, you need to take all these unique characteristics of video and couple it with the challenges that are faced with simple voice over IP, which include jitter (when packets are not delivered with a specified spacing), latency, and packet loss – the three headed monster of real-time protocols. To learn more about combating these tedious issues, check out our blog on the subject.

As more companies move towards a shared ecosystem and begin using SaaS and cloud computing, real-time protocols like VoIP and video could be adversely affected as overall network latency increases, and the real-time protocols, given their queuing priority, may also affect application performance more so than in traditional network architecture with centralized data centers. Before making any significant changes to a network, it is critical that you understand how all of the current network traffic is performing and interacting, including IP data and real-time applications. This is done by performing baseline assessments of your network. With solid baselines in place, you can easily determine the impacts of adding new applications or increasing real-time protocols, as well as whether or not a move to the cloud is advantageous or not.

Video and VoIP are not going away any time soon. In fact, real-time protocols, especially video, is only going to increase at ever increasing rates. More high-priority traffic like VoIP and video means even greater delays for your existing enterprise application data, which may already be under stress as you move to cloud or service-based applications. Understanding and possibly limiting video traffic to only that which is mission critical for your business may become a reality. Or maybe just a hop to 40, and or even 100G will do the trick, but that’s an expense alternative to address a proliferation of traffic which shouldn’t be on your network in the first place.

3 Tips to Ensure Video Quality on Your Network

As we discussed in last week’s blog, video is slowly encroaching upon both home and enterprise networks. In a recent Cisco report, all forms of video will be approximately 90% of the global consumer Internet traffic in 2015. We predict that more than 50% of enterprise network traffic will be video by 2015.

Video data types are unpredictable; require a lot of bandwidth; are sensitive to latency, jitter, and packet loss; and demand the highest QoS delivery. As video becomes more pervasive on your enterprise network you’ll need the right tools and approach to manage this demanding data type. Here are our top tips for preparing for video and monitoring video usage and quality.

Determine Overall Video Usage
One of the first things you need to account for is how much video is already being used on your network. The best way to determine this is by using packet-based network analysis systems capable of analyzing networks for all types of traffic simultaneously. With such a system, you will easily be able to see the throughput associated with data versus that associated with video (and audio for that matter) and to determine if the ratio is what you were expecting.

Armed with that data, you want to go one level deeper and review the packet loss, media quality, and number of video sessions/VoIP calls to determine 1) if video may be underperforming on your network or 2) how much video is affecting the performance of other mission critical applications.

Identify Unauthorized Video Traffic
Whether someone outside your company is pilfering your Wi-Fi to access YouTube or someone inside your company is spending too much time watching the World Cup, these three approaches can help you determine who is inappropriately using video and bogging down your network.

First approach: Look at your top nodes and protocols and see what they’re doing. If you have nodes that are exceeding your typical baselines check these first by simply expanding the node to see which protocols are in use. (We’ve covered baselining before! For a refresher, check out Tim McCreery’s Getting Network Baseline Right article (PDF) or Jim Thor’s Baseline Product Tips and Tricks.) RTP? You have a possible culprit. HTTP? Don’t stop there. You have all the packets so dig in bit deeper to see where the user is going. YouTube? It’s probably not work related.

Second approach: Check your overall network utilization and zoom in on spikes in traffic, which are often indications of video downloads. Zooming in on a spike will identify not only the user, but also from the protocols in use and the servers they are communicating with. You might find that someone is simply using the telepresence program you’ve installed.

Third Approach: Create filters and alarms. If you build custom filters for RTP (Real Time Protocol) and Dynamic RTP you can easily see the activity happening on your network that relates strictly to video and voice. You can also create address filters, like for YouTube, to determine if users are abusing certain sites and if this having a negative effect on your network.

Monitor High-Level Video Delivery
It may be that it’s quality, and not abuse, that’s of importance to you, especially when telepresence is being used. The best way to analyze for success is to look into each individual media stream, breaking it down into its primary audio and video components, and glance at your metrics. This approach allows you to determine the quality of service on each segment of video from picture to sound quality. You can continue to dive deeper into the packet by packet IP conversation, identifying exactly where problems such as quality of service is not being applied to certain packets or jitter exceeds typical guidelines for video. With this information, you have everything you need to find and fix any problems.

Designing your network to meet the influx of video on your network, as well as instilling a proper monitoring system for this sensitive data, will ensure that your network continues to stay stable and colleagues continue to stay happy while watching their favorite YouTube video or using Skype for conference calls.

IP Video – It’s like Living with a Teenager

Teenagers. Maybe you have one (or more) at home; maybe not. But we’ve all been one, so I know you can relate. Moody and unpredictable. Overly sensitive. Taking up more space than any human has a right to. High maintenance. They’re just so adorable.

Well, it turns out we have an exploding data type on our networks that behaves much the same way – IP video. In a recent whitepaper by Cisco, it was reported that all forms of video (TV, VoD, Internet, and P2P) will be approximately 90% of the global consumer Internet traffic by 2015. And per the report, that’s 90% of what will be 966 exabytes, or nearly a zettabyte, of IP data. To see what that looks like graphically, check out this link. Although video traffic on the enterprise side will not be as heavy as that on the consumer Internet, it will increase dramatically nonetheless, and will certainly be much more than 50% of the enterprise network traffic by 2015. It looks like you’re going to need both network management and high school guidance counselor skills by 2015 to manage enterprise networks.

With this dramatic increase in video traffic, video will be in competition with enterprise corporate data, enterprise application access, SaaS, and cloud computing. And given its tendency towards teenage behavior, you’re going to have your hands full. Below are a few details of how the characteristics of IP video can adversely affect your enterprise network.

Video is “bursty,” or in the teenage analogy, unpredictable, which is an undesirable characteristic for networks that work best under stable conditions – predictable and consistent. Packet sizes range all over the place, and often hit the network in large bursts. And of course these bursts are tagged with high QoS (quality of service) tags, so they take precedence over your other mission critical application data. Characterization of your IP video traffic, including weeding out business traffic from surfing, is critical to the health of your enterprise network.

Space Hog
Video is a bandwidth hog. One HD video stream can consume up to 20Mbps of bandwidth. So if five people are trying to stream a movie, it means that they are taking up 100Mbps of your network. This may not seem like a ton of traffic, but depending on the distribution of these users on your network, and the number of users serviced, bandwidth availability can certainly become an issue. And remember, the amount of video on your network is increasing all the time.

Overly Sensitive
Video is also very sensitive to latency, jitter and packet loss, even more so than voice, which we covered in this blog post. These sensitive protocols demand that your network is performing at its peak level to ensure that these issues are minimized. As video becomes more common on the network, performance demands will continue to grow and become harder to reach. Specific metrics and demands of latency, jitter, and packet loss are described in more detail below with this video segment and graph:

Due to the high performance demands of video, it is typically tagged for the highest QoS delivery as I mentioned earlier. However, as video traffic starts exceeding data traffic, enterprises will need to maintain different quality of service between users or video types since it is self-defeating for most of the traffic on a network to have the highest QoS tagging.

As video continues to grow, or as some might say invade, your enterprise network, it is more important than ever to plan and design your network to carry video. And just as the teenage years pass, the video phase will also pass in time, allowing networks to again hum along in a predictable pattern. That is, until the next disruptive technology come along! In next week’s blog, we’ll be providing some best practices on designing, monitoring, and managing your network to help that teenager grow up.