Video conferencing bandwidth management and planning guide

by Dan Devine

Video conferencing enables members of an enterprise's distributed workforce to connect face-to-face no matter where they are, increasing flexibility and improving communication provided, of course, that your network can stand up to all that video conferencing bandwidth strain.

An individual video conferencing call requires a substantial amount of bandwidth; a high volume of calls can cause nightmares for network managers who haven't properly prepared for the flood. How can you ensure that your network is ready for business video conferencing bandwidth demands?

The news articles, columns and expert advice from the SearchUnifiedCommunications.com archives that are compiled in this video conferencing bandwidth learning guide will help you cover all your networking bases when implementing video conferencing solutions. From fundamental issues like calculating how much video conferencing bandwidth your setup will require to more nettlesome specifics like handling a desktop video conferencing deluge and delivering high-quality video conferencing to branch offices, we've got the expertise you need to keep your users connected and your network strong.

In this video conferencing bandwidth learning guide, learn about the importance of making sure your network can handle the bandwidth demands of an enterprise video conferencing implementation. Get tips on calculating video conferencing bandwidth, find out how to manage bandwidth without forsaking video conferencing quality and learn about the role that a Quality of Service (QoS) deployment can play in the process.

Check out the following articles, tips and videos for an in-depth look on these topics and more:

• Calculating video conferencing bandwidth requirements for enterprise deployments : The first step to a successful video conferencing setup? Determining just how much bandwidth you'll have to devote to supporting multiple high-quality video conferencing calls. We'll help you do the math.

• Understanding and controlling video conferencing bandwidth demand: After you've calculated how much video conferencing bandwidth your implementation will require, you've got to make sure supporting it won't adversely affect mission-critical applications. Leveraging QoS, network design and call admission control can give you the best of both worlds.

• Balancing video conferencing bandwidth demands with video quality needs: It's a simple rule of video conferencing: The higher the quality of experience you want to deliver, the more network bandwidth you'll need to support it. How good does the video need to be for your users? How much bandwidth will that demand? You've got questions; we've got answers.

• Video: How does video conferencing deployment affect the network as a whole?: After it's been deployed, video conferencing can quickly account for as much as half of total network bandwidth consumption. How can you manage that kind of load? In this video interview, NetForecast Principal John Bartlett and TechTarget's Sue Fogarty discuss the challenges network managers and architects face.

• Video conferencing over the WAN: A network design checklist: Proper configuration of the enterprise wide area network (WAN)—including making sure the enterprise WAN has enough bandwidth available to cover demand—is critical to ensuring high-quality video conferencing service delivery. This list of WAN video conferencing requirements will simplify your network design process.

• Keep desktop video conferencing from overloading the WAN with smart network planning: When you bring video conferencing to your users' desktops, you open the door to the prospect of many new video sessions being initiated at the same time, which could overload already-taxed WAN links. Learn how careful desktop video conferencing network planning and provisioning can spare your WAN an untimely demise.

• Video conferencing in branch offices over iVPNs: Bandwidth strategies: WAN optimizers and link aggregation could be valuable tools for enterprises looking to ensure bandwidth availability and performance stability when providing quality video conferencing to branch offices over an Internet VPN (iVPN) linked to the enterprise WAN.

• UC and video integration: Alleviating video conferencing bandwidth concerns: Concerns about bandwidth—namely, the need for a lot of it and the cost of procuring it—rank among the major factors limiting widespread deployment of video conferencing and other video technologies within UC setups. With our help, though, you can address those concerns and launch a successful UC/video integration project.

(Sources - http://searchunifiedcommunications.techtarget.com)

WAN video conferencing network design requirements for QoS

Video conferencing is a real-time communications technology, like VoIP, which requires special treatment on the IP network. The wide area network (WAN) is a critical component of the infrastructure supporting video conferencing and must be properly configured in order to ensure high-quality video conferencing service delivery.

The critical requirements of the WAN video conferencing network design are as follows:

* To ensure that the WAN has adequate bandwidth.
* To properly classify traffic and support that traffic in a dedicated class.
* To support call admission control for bandwidth management.
* To properly locate the multipoint conferencing unit or bridge.
* To measure and monitor the WAN vendor.

Let's take a look at each of these requirements in turn.

# Determining adequate bandwidth for WAN video conferencing

Video conferencing sessions can consume significant amounts of bandwidth. Video conferencing can operate with as little as 400 Kbps of network traffic but may operate as high as 4 Mbps or even 6 Mbps of network traffic per call. The network designer must first determine the bandwidth of each video call by comparing the different resolution and frame rates available and determining which settings are best for the business application. The network designer must then determine the number of concurrent calls from each WAN-connected location. The call rate multiplied by the number of concurrent calls will determine the bandwidth requirement on each network access link. Remember to add IP overhead. Traditional video conferencing bandwidths are given as the transport bandwidth (e.g., 512 Kbps) where what the network actually experiences is about 20% higher (e.g., 615 Kbps). This is because video conferencing bandwidth values date from the days when it was all being carried on IDSN, which does not have any overhead. Signaling is out of band, but in an IP network we need overhead to create the packet headers that get the data from one computer to the next. This 20% is the overhead of the wrappers that let the IP network know how to handle the data (addressing, timing, protocol encapsulation, etc.).

# WAN traffic classification

The voice and video streams from a video conferencing endpoint must be given priority treatment in the network (overlay and converged) to maintain audio and video quality. A network class should be dedicated to video, and this class should be of a higher priority than all other application traffic except VoIP. The correct marking for this class will be provided by the WAN vendor. This marking should be put on the IP packets by the endpoint itself through proper configuration of the video endpoint. The network should be designed to trust the endpoint based on its IP address, subnet or port range.

# Video conferencing CAC

Once the bandwidths for the network have been calculated and put in place, the video conferencing application must stay within the design constraints. As additional systems are deployed, it becomes possible for video to overdrive the network, which will create packet loss and thus poor-quality video. The video conferencing infrastructure must have a call admission control (CAC) mechanism in place so that when the bandwidth for a specific network link is fully utilized, subsequent call requests which use that link will be denied.

# Locating the WAN video conferencing bridge

The video conferencing bridge is a bandwidth hotspot because all video conferencing calls participating in multipoint conferences must directly connect to the bridge. Thus, the bandwidth demand of the bridge connection can be significant. The best location for the bridge is in a collocation facility directly connected to the WAN core. This location provides inexpensive high-bandwidth connectivity and ensures that the design will scale as additional video conferencing endpoints are added to the enterprise.

# Trust and verify WAN video conferencing QoS

Network monitoring is a critical component of maintaining a high-quality video conferencing service. A path-based measurement tool should be used to measure the behavior of the network. The statistics gathered by traditional data network tools are not sufficient for monitoring the behavior of networks for voice and video conferencing. The voice and video monitoring tool should be an operational tool that collects information on a 24/7 basis and stores this information in a database. The tool will allow forensic analysis, trending, triggers based on thresholds, and real-time views of the behavior of the network in support of video conferencing. Currently, no video vendors have this kind of tool, but other vendors sell video network management tools.

# WAN video conferencing network design takeaways

These critical steps are all needed to ensure consistent, high-quality video service delivery across the WAN. Work with your WAN vendor to ensure that it has the right capabilities and that your network design meshes with the WAN service provided. Spending the time to get a good scalable design in place will pay off as video conferencing becomes an integral communications tool for the enterprise.

(Source : http://searchenterprisewan.techtarget.com)