HTTPS is changing the mobile traffic management game

Telecoms.com periodically invites expert third-party contributors to submit analysis on a key topic affecting the telco industry. In this piece John Reister, VP of marketing and product management for Vasona Networks, argues that as more traffic is encrypted managing what can’t be seen introduces new challenges.

If you blinked, you may have missed it. Seemingly overnight, the volume of mobile data packets sent using the HTTP Secure (HTTPS) protocol skyrocketed to now comprise a large portion of all mobile broadband traffic during peak periods – as much as nearly 25 percent, according to ATIS. In certain European engagements, we’ve seen that number go as high as 65 percent. This trend is largely driven by major companies like Google, Facebook and Netflix favoring the protocol for traffic delivery.

All indicators point to even more app makers embracing HTTPS in the near-future. This is great for privacy. But for mobile operators pressured to deftly manage congestion in the face of ever-surging demand? HTTPS is a thorn that can render obsolete many of the approaches they’ve used successfully to date.

Behind The Veil

Managing HTTPS traffic requires working around a bevy of limitations. Mobile operators can see that there is traffic in their network, but they can’t modify the content in any way. This means that performing “optimization,” a method that aims to transrate or transcode files, is not an option. With most of the video traffic coming from HTTPS-embracing sources like Netflix, YouTube and Facebook, deploying a solution that can’t work with this traffic is a non-starter.

What about using TCP proxies and deep packet inspection? Again, a problem emerges. The data is encrypted, restricting anything more than a superficial glance at the basic properties of a session. This restricts feedback and control on a per cell basis. As mobile operators become ever more surgical in how they manage user experiences, not being able to affect experiences at the cell level represents a big step backward.

Managing Secure Traffic For Great Customer Experiences

Mobile operators need a traffic management solution that works with HTTPS. It is not practical to try solving quality of experience issues by simply adding more, expensive, capacity.

The industry has a path forward in a new approach: dynamic rate control with feedback (DRCF). DRCF is proving to maintain great mobile experience in congested cells across deployments around the world. This includes more than 25% improvements in latency reduction and throughput increases of both video and browsing under congestion situations. The approach lets operators modify how much capacity is used by a session considering all types of traffic in a cell facing congestion, utilizing real-time information about how individual sessions are performing.

As it turns out, DRCF is particularly well-suited for managing HTTPS traffic because it considers all simultaneous sessions and works with whatever understanding can be gained about them. There’s no requirement for full visibility of each and every pertinent session’s content like other approaches.

DRCF actually gains new comprehension of traffic, even when it is encrypted. Leading-edge methods in combination with various heuristics and session transmit characteristics like downstream rate, downstream versus upstream, gaps between packets and packet size determine what kind of session is hiding in encrypted traffic. By categorizing sessions using this method, mobile operators can leverage DRCF to look at packet flows and determine whether a consumer is having a good or bad experience.

Once mobile operators have gotten this far, they can manage the traffic for the application sessions using feedback on all flows within each cell to ensure the best experiences during periods of congestion. And all of this happens without having to modify content by transrating or transcoding. And without attempting to decrypt the traffic.

Smooth, Secure Traffic Flows

DRCF delivers the best of both worlds: traffic remains secure (as it should be), with mobile operators remaining free to manage traffic in a way that ensures every subscriber gets a great experience. Mobile traffic management vendors will have to change with the time, but for now, there is a definitive approach that works. With HTTPS traffic increases showing no signs of slowing, key stakeholders in the mobile industry would be best served by starting their journey today.

John Reister is vice president of marketing and product management for Vasona Networks, helping to drive the company’s collaboration with mobile operators to reduce cell congestion and deliver better subscriber experiences.