Deep Inside The Internet Backbone

Why This MattersCDNs could be handling as much as 71% of all global internet traffic by 2021, per Cisco Systems.

Related: The Lay of the Land

Speaking at video-industry events this year, Charles Kraus noticed the same question popping up at each one: Just how many over-the-top offerings exist?

So Kraus, the senior product marketing manager for content delivery network (CDN) services provider Limelight Networks, took on a daunting task. He tallied up every OTT offering he could find around the world.

His rough data: the number of OTT services available today - small, medium and large, from the most niche-oriented to the most popular - has passed the 3,000 mark. And that's a low-end approximation, he said.

The rapid growth and sheer number of online video services does mean great business for CDN companies: According to a June report from Cisco Systems, in 2016 CDNs were responsible for carrying just more than 50% of internet traffic worldwide. By 2021, Cisco forecasts that 71% of all internet traffic will run through CDNs, with those services handling a video content load that's expected to account for more than 80% of all internet protocol traffic.

All of this growth has put the backbone of the internet on the X-ray screen. CDNs make up a stratum in the Internet, and offer all kinds of content delivery services: video-streaming, downloads, caching, etc.

The added video traffic has CDNs keen on associated challenges: reducing latency, ensuring content security and keeping up to speed with every delivery standard used by content companies. spoke with Kraus and others in the CDN space about how they're tackling today's onslaught of entertainment services.

Latency, Latency, Latency

It's a painful reality: if you're watching a live event via an online service, you'll be behind the over-the-air or satellite broadcast, even if it's just by a few seconds.

A lot of that has to do with the video specs most widely used today for live, digital content delivery, according to Ted Middleton, chief product officer for Verizon Digital Media Services, which operates the Edgecast CDN service.

Take the popular HTTP Live Streaming (HLS) protocol as an example. Traditional recommendations in the HLS spec typically induce an approximately 30-second time-behind-live [delay], based on the number of segments and segment durations required to generate a live playback manifest, Middleton said. Other formats have different recommendations, but nearly all of the modern HTTP-based, adaptive bit rate formats have some amount of latency induced in order to provide reliability and reduce buffering.

It makes sense: Delivering live video content digitally must account for internet bandwidth and the number of people viewing at any one time. But that doesn't make the end user any more patient.

An early July study from live-streaming tech company Wowza Media Systems found that any delay of 15 seconds or longer for a live-streaming sports app was detrimental to viewers, with spoilers readily accessible on social media. Wowza's study of live streaming apps in general found latency to be as low as nine seconds, but also as high as 101 seconds.

[Live events] only happen once, and there's no tolerance for error, John Bishop, chief technology officer for CDN heavyweight Akamai, said. Unlike the earlier days of on-demand streaming, when the occasional glitch was accepted, any hiccup in live delivery isn't an inconvenience to the audience - it's a disruption.

What Akamai and other CDNs are doing to make live digital video closer to truly live is twofold: First, make sure they're able to ingest the content from its point of origin, as close as possible (with, say, the signal being picked up via a production truck or master control), in order to quickly transcode and deliver across the network. Second, coordinate with client-based software (especially video apps, but also hardware) to more easily communicate with CDNs.

This can help make sure the video is optimized for the viewer's device capabilities, network type and conditions, Bishop said.

Part of facilitating the former is the reason you'll increasingly hear CDN and edge in the same sentence in the years to come: A CDN's best bet for a seamless user experience is to deploy servers and nodes as widely as possible, with the goal of narrowing as much as possible the geographic proximity between the network and the end user.

One of the critical aspects of providing a quality streaming experience for consumers is moving the content as close to the edge of the network as possible, [something] traditionally done with an edge CDN provider, said Ed Haslam, chief marketing officer for Conviva, a digital video analytics firm whose roughly 200 clients (mostly in the OTT space) are largely reliant on CDN services.

They're doing that to decrease the latency when you hit play in the video player, get the content as close to the viewer as possible, to minimize the video start time, which is often critical for consumers, Haslam said.

Content Security

As CDNs are challenged with handling more content for worldwide audiences, they will need to store it in and move it to more locations. And security concerns among content owners are always at the forefront, CDN representatives agreed.

As a shared service, the main challenge for us is that not all of our customers have the same content security needs, and many leverage different security solutions, Jennifer Cleveland, VP of content sales for CDN company Level 3, said. The challenge becomes making sure our system is flexible enough to work with each customer's needs, without having to create a completely customized solution for each. [And] it can require extra time and diligence in the onboarding process.

Limelight's Kraus echoed

LINK:	http://www.broadcastingcable.com/news/technology/deep-inside-internet-...
	See more stories from bandc

Most recent headlines