Openwave Mobility’s Mobile Video Index (MVI), with data gathered from over 30 mobile operators, has found that Google QUIC has grown at an alarming rate. Here is why it is critical for mobile operators to stay on top of this.
You cannot argue with the fact that Google has made phenomenal strides since its inception in 1998 and now has an omnipresence that affects almost every facet of life. Especially in mobile.
At any given moment, Google’s data is traversing mobile networks right across the world. The numbers are mind boggling. Each second Google is said to process over 55,000 searches and 125,000 videos. No prizes for guessing that a majority of that activity is over wireless.
Time to party or panic?
Google introduced QUIC back in 2013 as an experimental protocol to reduce TCP connection and transport latencies. Today, around 75% of the traffic is encrypted in mobile data networks. TCP, in combination with TLS, requires three round trips before the actual data can be sent. QUIC, on the other hand, minimizes the number of setup round trips by combining UDP transport and its own cryptographic handshake. For connections to the same origin server, QUIC facilitates a zero round trip time.
QUIC also re-implements TCP loss recovery, over UDP and, by using multiplexed connections, it eliminates TCP’s head-of-line blocking. This ensures that that lost packets do not block any other stream but only those with data in it. Last, but not least, QUIC moves congestion control to the application and the user space, enabling a rapid evolution for the protocol, as opposed to kernel space TCP.
So, isn’t QUIC all you need to transport data in mobile environments? Not quite. QUIC performance gains compared to TCP/TLS, while still positive, have found not to be that significant as for desktop, in particular for video content.
According to Google, for Android mobile devices using the YouTube app, only 65% of QUIC connections benefit from a zero RTT handshake, as opposed to 85% on desktop. Also, the YouTube app downloads video data ahead of the video playback, negating the side effects of TCP/TLS connection setup delays and therefore reducing QUIC’s benefit over TCP/TLS.
Nevertheless, and first, the good news: QUIC benefits are still tangible. On mobile Android devices, Google claims that QUIC has helped to reduce latency of Google Search responses by 3.6% and YouTube video buffering by 15.3%.
The rise and rise (and rise) of QUIC
Based on live data from more than 30 mobile operators around the globe, Openwave Mobility’s MVI found that by November 2017, QUIC represented 20% of the total mobile traffic. The MVI found that in just two years, Google QUIC grew at an eye-watering CAGR of 284% since its introduction in Chrome desktop browsers.
There are multiple reasons why QUIC has grown so quickly and why it looks like it will keep growing:
- Google applications such as YouTube utilize QUIC as the default transport protocol for Android devices since July 2016. One in two people watch YouTube on mobile.
- While some of us thought QUIC would “only” grow linearly with Android traffic, iOS devices have also started to adopt QUIC for YouTube. Google is moving to QUIC on the latest iOS and YouTube app versions.
- Beyond Google, applications such as Snapchat have started to adopt QUIC, and more could follow in 2018.
- An IETF working group is working to standardize QUIC, which is looking at adopting TLS 1.3 for transport security, replacing QUIC’s crypto protocol.
QUIC is a party pooper for mobile operators
Now for the sobering news. QUIC is a conundrum for mobile operators, both from a data monetization and subscriber Quality of Experience (QoE) perspective.
Why? As an encryption-based protocol, traffic is not visible at all to the mobile operator, meaning that they cannot use traditional traffic management tools to control the cost to deliver the content, manage subscriber QoE and ultimately monetize data.
This is particularly alarming when it comes to video content. According to MVI data, video accounts for approximately 58% of the total mobile internet traffic. Video represents 64% of the total QUIC traffic.
Currently, mobile video in QUIC is using an Adaptive Bitrate (ABR) delivery mechanism where the server maintains several variants encoded at different qualities and bitrates. The client and the server negotiate the best version of the content that can be delivered for the current network conditions.
The concept seems ideal; the technology, however, introduces challenges to operators as ABR is an inherently ‘greedy’ protocol, consuming the highest bit rate that it can sustain unless video playback is interrupted. It also does not take collective QoE into account as it does only look at the individual video flow that it is serving. QUIC, in conjunction with ABR, hampers operator efforts to manage network congestion.
Google has certainly demonstrated their capability to reformulate internet standards – to their benefit. So, what steps can mobile operators take to manage incursions on their networks?
Mobile operators must review their mobile data management strategy to identify and differentiate current and future traffic streams – such as QUIC and Facebook’s Zero Protocol. Unfortunately, QUIC introduces additional challenges to those observed when managing other protocols built on top of TLS, such as HTTPS. The benefit of multiplexing multiple streams over a single connection, comes with the added downside that it is impossible to differentiate between the different streams; as the signalling header which indicates the stream identifier is also encrypted.
New solutions available today combine transport layer optimization, encrypted traffic classification techniques and real-time RAN utilization insights to provide with a range of selective traffic management options for QUIC. These include content and user activity differentiation to create hand-crafted mobile data plans as well as QoE management that helps reduce congestion and the burden on the RAN.
Looking to the future
At Openwave Mobility, we have witnessed how these solutions are used to deliver the same amount of QUIC video with 20% less data. As a result, mobile operators can achieve reductions in the number of congested cells by 15%, facilitating fairness in the distribution of video bitrates (and therefore video quality) across subscribers sharing physical network resources.
It would be fair to say that nobody saw QUIC coming - but coming it sure is. According to MVI data, by November 2018, approximately 90% of internet traffic will be encrypted and QUIC will be 32% of global Internet traffic. So, will mobile operators bury their heads in the sand and mourn – or will they be ready for the fight back to take control of their network and their subscribers’ QoE? Watch this space.