Can your network handle HD video?
- 16 April, 2008 09:45
Consider this: In the week following September 11, 2001, your users were glued to their television sets tracking breaking news. If an event of similar proportions happened today, they would expect the enterprise network to be able to handle not only real-time video feeds but also high-definition videoconferences and surveillance, as well as instant access to social-networking tools.
Are you ready?
Mark Tarleton, manager of Webcast communications at defense contractor Raytheon, says he is constantly working to be able to answer that question in the affirmative for the company's 73,000 workers around the world. Like many of his peers, Tarleton knows firsthand the growing sway that video holds in organizations today, as executives and users alike pressure IT to support videoconferencing, 24/7 video-over-IP surveillance, such rich-media social-networking tools as podcasting, and IPTV. He also sees the freight train that is HD video headed straight for the enterprise.
"What we're trying to do is deliver video in a way that's going to coexist with other traffic on the network," Tarleton says. That's a pretty tall order when HD is expected to send network requirements into the stratosphere.
"Everything surrounding the delivery of HD video will require a five to 10 times increase. You're going to need that much more bandwidth because it has that much more sensitivity," says Inbar Lasser-Raab, director of network systems at Cisco. HD video boosts the average video stream of 300Kbps to more than 3Mbps.
Lasser-Raab and Tarleton agree, however, that as with most advances in technology, bandwidth alone will not solve the problem. Instead, IT teams must take a strategic approach to not only delivering high-quality video applications but also protecting other mission-critical business traffic.
Demand for video is rising
A recent study by research firm Illuminas, commissioned by Cisco, found that 66 per cent of the 150 global companies surveyed said they view video as the top benefit for advanced collaboration, and 34 per cent said they expect to use video and Web conferencing for internal collaboration within the next five years. More than 30 per cent said video and Web conferencing are among their top five investment priorities.
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For Tarleton, this is a long way from the grass-roots movement that brought video to his company in 2000. "Videoconferencing began in one business unit because the leaders wanted to communicate with their people without traveling to each site for town-hall meetings," he says. Since then, with a directive from top executives, he has moved under the IT umbrella and supports more than 300 live Webcasts a year. "Many are brown-bag sessions so that engineers can knowledge-share," he says.
Val Oliva, director of product strategy for Foundry Networks' Enterprise Business Unit, says it's exactly this kind of uptick in corporate-sanctioned, user-generated content that is forcing IT organizations to retool their networks. From posting training videos on the corporate intranet to creating on-the-fly, live feature sheets for sales teams, organizations are becoming treasure troves of video-based information, he says.
Many companies have makeshift production studios, and most laptops today are shipped with video cameras. "IT groups have to start thinking of everyone as not only a consumer of video, but also a possible source," Oliva says, adding this has dramatic implications for capacity planning and network design.
Start with policy
Before IT teams can start reengineering their physical architecture to support widespread use of video applications, they have to be clear about corporate policy, says Scott Morrison, research director for enterprise network services at Gartner. "Bandwidth-hungry video applications create such an order-of-magnitude demand on the network that when they aren't deployed as part of a corporate strategy, you run into problems," he says. Without proper planning, organizations can wind up draining the coffers for bandwidth and other piecemeal solutions.
Morrison recommends, first, that companies analyze their current video use. He suggests using automated network monitoring probes to discover who is using which applications. "Also, determine how much traffic is being generated for each type of video functionality," he says.
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Next, companies should decide whether video-use levels are acceptable, and map out a corporate policy defining what users can and can't do with video applications. "Estimate the productivity gains they get from deploying rich media, then decide how much you can afford to spend to achieve that productivity," Morrison says. For instance, will posting training videos for call-center employees lead to better customer service?
Companies also have to determine the priority they want to assign video applications. Are video applications more critical than their VoIP applications? What about their ERP and CRM programs? Morrison says it's important to get everyone on the same page regarding video's role because this will have a severe impact on an organization's architectural design.
Re-architecting a network
As a company digs into the design of its network, it's important to keep in mind video's sensitivity, Cisco's Lasser-Raab says. "People have very sophisticated networks at home, so if they get bad video quality at work, they won't use the business applications. With [VoIP], IT executives plan for 50 per cent to 60 per cent utilization and a spike of 80 per cent. With video, you need to prepare for an even bigger increase," she says.
Sven Rasmussen, a LAN/WAN specialist at CDW, says a good first step is to increase LAN speeds to 1G with 10G uplinks to core infrastructure. "However, this doesn't alleviate the ultimate roadblock of your Internet connection," he says. For that, he recommends creating a budget for the company network. "You have to engineer for all your applications, not just video," he says.
Rasmussen recommends installing content filters for applications that aren't mission critical, as well as for certain types of data and access to unapproved Web sites. Next, companies should roll out traffic-shaping and QoS tools that let them compress, cache and prioritize traffic. "Video and voice are two types of traffic that if they're not received in perfect order, won't make any sense, so make sure those applications get the most bandwidth they need vs. e-mail and HTTP, which can be retransmitted," he says. IT teams won't have to worry about separate tools for traffic shaping and QoS much longer, he says. "With high definition and IPTV gaining traction in the next five years, it'll be commonplace that all networking equipment will feature [QoS] and traffic optimization tools," he says.
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Deploy CDNs and take advantage of multicast
Raytheon's Tarleton agrees that companies have to engineer their networks as a whole, but he also extols the virtues of video-specific architectures.
For instance, he believes a combination of content delivery network (CDN) technology and IP multicast is essential for delivering video live and on-demand to Raytheon's more than 400 sites. "If you're thinking about live streaming, you need to think about multicast," he says.
IP multicast is a technology that lets a company efficiently deliver streaming media to thousands of receivers by replicating the packets throughout the network. Tarleton warns that there can be hitches, however. "It's not always the panacea it's thought to be when it comes to video. The farther away you get from the multicast publishing points, the more problems you see," he says. For instance, because streaming video uses interframe compression, it needs a key frame. If those packets are delivered out of order, the key frame might be missing, and the video freezes. To deal with this problem, he recommends reproducing the multicast closer to the user.
Tarleton keeps close tabs on the quality of his video streams using monitoring tools that look below the packet levels into the compressed frames. "I'm not looking at every stream, but I've planted some sniffers here and there to look at certain access points," he says.
Tarleton says for further insurance during live broadcasts, he's coupled a CDN with his multicast system to redirect clients closer to publishing points on edge devices across the enterprise. He also uses the CDN for on-demand streams to make sure everything is positioned ahead of time for easy access. "When we first got into video, [CDNs] were expensive. Now, not only are they cheaper, but some of the newer servers have the technology built in," he says.
Although Tarleton has started to dabble in HD videoconferencing, for now he says he allows media groups to shoot in HD and then he transcodes it to the standardized 300Kbps rate for streaming. If his users want the original HD quality, he creates a disc for them.
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Tarleton says although work still needs to be done, algorithms such as the ITU-T's H.264 video compression standard are easing the transition to HD.
Morrison says that HD could pose challenges for compression technologies because of the overhead. The reason: Humans have a limit of around 250msec to register face-to-face communication. "If I talk to you and you don't show some inference of having received my message within that time, my brain tells me something is wrong. Therefore, if you have any latency - even 10msec - it can have a grand effect on the user experience," he says.
Don't forget about storage
While Dave Woods, manager of IT at the Niagara Falls Bridge Commission, says he's got the pipes to handle the move to HD for his 195 IP surveillance cameras, it's the storage that would be the pain point.
"As you increase your resolution to 1M, you start to have major issues with storage," says Woods, whose joint Canadian-US agency oversees three border crossings spanning the Niagara River between western New York State and southern Ontario. "We've got five computers receiving video streams from our cameras using a first in, first out-to-disk system where the oldest video gets deleted first. Today, we can store that video for 30 days. With HD, that would immediately get cut down to 10 days," he says.
To tackle this problem, rather than doing a widespread upgrade to 1M cameras, Woods' team is evaluating where HD would be of most use. "We'd probably need it for facial recognition and any locations where you're handling money. For instance, high-resolution might help distinguish between US and Canadian currencies. These are select needs and will definitely be based on a risk analysis," he says.
James Doig, security consultant for SystemExperts, says it's critical for companies to keep storage top-of-mind when they're considering video. "For many industries, not only do you have to keep e-mail as a business record, but also videoconferences and other streams," he says.
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Doig also says IT teams need to be as cautious about video traffic as they are about other data streams. "It's a mistake to think that videoconferencing and other types of video applications don't open you up to vulnerabilities. Hackers can still punch a hole in your firewall through your video devices," he says. The best defense is to check for bad or default configurations, and keep your applications and firmware up to date.
Communication is key
When it comes to provisioning video on the network, Morrison says interdepartmental communication is critical. For instance, if an executive wants to broadcast to the company at a certain time, IT should alert other departments so that there's no impact on traffic from payroll or marketing.
Tarleton agrees, but says that sometimes can be tough. "I'd love to be able to tell you we look at everything that's planned for the network and shape accordingly, but when you look at an organization this large and diverse that spans so many time zones - that can be challenging," he says.
See: 10 tips for a successful video rollout
Gittlen is a freelance writer in the US. She can be reached at sgittlen@charter.net