Telecoms.com recently partnered with Mark Davis from ByteMobile at Citrix to discuss the impact encrypted content is having on mobile networks. In this interview, Davis explains how it’s taking up an increasing share of traffic on the network, brought in by the increasing relevance of content providers and pending standards like HTTP/2.

How much encrypted traffic do you see on mobile networks?

From our customer deployments, we see that between 50 and 65 percent of mobile data traffic is encrypted. This is up from 10 to 20 percent in 2013.

What are the sources of this encrypted traffic?

The answer might be surprising to some, as one might naturally think that the content would be related to necessarily secure transactions like banking. In fact, the primary sources are YouTube, Google (non-YouTube) and Facebook.  More important than the source is the fact that nearly half of that encrypted traffic is video. This correlates well with the video percentages across the broader network.

Why are these sources encrypting their content?

Only those sources could tell you for sure but there are clues that suggest one answer. Obviously, watching a video is not like conducting a banking transaction. The latter have been encrypted for years, for obvious reasons. The clue lies in the fact that YouTube, Google and Facebook have advertising-based business models. The more they know about your browsing behaviour, the more effectively they can target ads and the higher CPM they can collect. The more that others can do the same, the less of a competitive advantage YouTube, Google and Facebook have. It’s rational for these big content providers to want to protect their competitive moat and encryption is a natural means of doing so. By encrypting content, they can continue to observe browsing behaviour on their properties, while making it much more difficult for others to do so.

What other changes do you see in the traffic profile on mobile networks?

Hidden beneath the well-publicised rise of encryption is a not-so-publicised transition taking place in video delivery. Although modern adaptive bit rate (ABR) has been around since 2008, only now are we seeing significant mobile video traffic shift from progressive download (PD) to ABR. That split is at roughly 50-50 now in most of the networks in which we’re present. When you overlay this trend with continued growth in both encryption and video and consider industry developments such as the recent announcement by Netflix that it will encrypt all of its content, ABR’s role as the largest encrypted content category appears certain.

What are the implications of encrypted content for mobile operators?

Lack of visibility into the nature of the traffic is the obvious first implication. That lack of visibility makes it difficult to: make commercial decisions based on the content being consumed, forecast traffic, and proactively manage that traffic. It also has implications for subscriber experience, including added latency, less consistent video quality and higher incidence of congestion due to the inability to manage wasted traffic volume.

Do operators need to manage subscriber quality-of-experience (QoE) for encrypted content like ABR video?

It’s the operators or no one. Only the operator has the network visibility necessary to enable ABR clients – be the traffic encrypted or unencrypted – to make decisions based on more than just their immediate surroundings. The operator has an all-encompassing view of subscribers, devices and clients, as well as the ability to integrate both historical and forward-looking information about them into decision-making. Absent this crowd-sourced knowledge and video delivery is inherently hamstrung.

Why should the operator care about managing traffic that content providers seek to make invisible? Because subscribers evaluate the operator based on their experience, regardless of whether or not the content is encrypted.

Is encryption a fad or here to stay?

All Indications are that it’s here to stay, as, at the very least, it’s required for secure transactions. Emerging standards such as HTTP/2 may also serve to drive greater use of encryption. The open question is whether the widespread use of encryption by the likes of YouTube, Google and Facebook will cause enough commercial and technical disruption to operators that some further accommodation will be required. This will play out over a couple of years, we expect.

What advice do you have for operators?

Recognize that encrypted content is an evolution of the mobile ecosystem akin to the rise of video in the mid-to-late 2000s. The technological tools necessary to enable operators to effectively manage that video traffic for the benefit of subscribers and the network evolved over time. We’re at the cusp of an era in which encrypted ABR video is the dominant traffic category and, already, non-intrusive tools exist to enable operators to characterize and manage this traffic. Ask vendors what they can do to help you.