The world's obsession with digital information shows no signs of abating. As users create, share, and consume content, network traffic volume goes up, growing an average of 30-50% annually.
In this article, my colleague Brain Lavallée chronicles the most popular cloud-related applications and technology that are putting pressure on today’s networks. Brian is a Director of Technology & Solutions Marketing at Ciena.
The world's obsession with digital information shows no signs of abating. As users create, share, and consume content, network traffic volume goes up, growing an average of 30-50% annually.  The increased adoption of cloud technology has made round-the-clock access to content easy.
However, connecting users to content is not just about volume. Bandwidth is driven by applications, which have changed how, when, and where bandwidth is created, used, generated, and originated, making it far less predictable and much harder to manage. The following eight examples show how unpredictable traffic impacts the metro network.
- Popular video content release
Netflix is the biggest single driver of traffic on the Internet, accounting for 34.2% of all downstream usage during primetime hours. The company's new business model of appealing to binge viewers by releasing entire seasons of programs at the same time creates tremendous traffic spikes. 16% of Netflix subscribers streamed at least one episode on the day Season 2 of House of Cards was released. 
- Mobile handset apps
With an installed base of more than 600 million devices, network operators need to be prepared for Apple's iOS upgrades or suffer from the deluge. Over 50% of Apple device users upgraded their device to iOS 7 within two to three days of its release, with 30% upgrading within the first day. One study showed that 22% of capable devices upgraded to iOS 7 within 10 hours of release. At nearly 1GB per install, each upgrade sucked up bandwidth quickly. Upgrades are predictable, but the traffic from users learning about new features, posting opinions in online forums, or uploading HD how-to videos can increase traffic for days or weeks.
- 24-hour news cycle
While TV is still the primary news source for consumers, a growing number—currently 28% of those under 50 in the U.S.—turn to the Internet for breaking news. Global news coverage of events such as political upheavals, sporting events, or natural disasters is viewed online instantly by billions. To serve the 24-hour news cycle, data is pulled off servers around the world and around the corner, creating geographic unpredictability.
- Viral videos
Who could have predicted that a Korean singer would rack up two billion YouTube views? This milestone set by "Gangnam Style" is not the only time a viral video has jammed up networks. Ylvis' "The Fox (What Does the Fox Say?)," Jean Claude Van Damme's "Epic Split," or even kitten antics demonstrate that viewers' interests and demand windows are unpredictable. HD is the preferred format for viral reposting, forwarding, and copy-catting. Viewing statistics for highly social videos differ from those for non-viral videos; viral videos tend to peak more sharply and drop off more rapidly. 
- The shift from standard-definition to HD television
HD needs more bandwidth to stream content. YouTube now allows videos to be posted in HD; every minute, 48 hours' worth of video is uploaded to the service. HD will soon be replaced by 4K, which has four times the pixels of today's 1080-pixel HD, creating even more exponential bandwidth growth (Netflix recommends a 25 Mb/s connection for that service).
- End-user devices
245.4 million tablets will ship worldwide in 2014, along with 1.4 billion smartphones.  Due to their limited storage capacity, these devices require network connectivity to deliver full enjoyment to their users by pulling content, video, and games out of data centers. The more powerful these devices become, the more bandwidth they use. Studies have shown that traffic originating from tablets and mobile phones is growing annually by 104 and 79 percent, respectively. 
- Internet of Things
Everything from jet engines to refrigerators is joining the Internet of Things, pushing networks to the brink. In a new Boeing 747, almost every part of the plane is connected to the Internet, recording and, in some cases, sending continuous streams of data about its status. General Electric Co. has said that in a single flight, one of its jet engines generates half a terabyte of data.
- End-user mobility
Devices are highly portable and change traffic patterns throughout the day. To manage the traffic, service provider networks are becoming larger and more complex. Traditionally, service providers built out networks by adding more and bigger routers; because this traffic is unpredictable, networks are often overprovisioned to handle unforeseen spikes. With this approach, networks are not getting smarter as they grow. Instead, they are becoming more complex and power- and space-hungry, causing data centers and central offices to run out of both physical space and electrical capacity. In many facilities, new equipment cannot be added unless something is removed first—there is just nowhere to put it or plug it in.
This article originally appeared on the Ciena Insights blog.