Video: HTTP over QUIC is the next generation

There’s a lot to like about HTTP/3 from encryption as standard, faster set-up time, better compression and promises better throughput by removing head-of-line blocking. A new protocol making its way through the IETF and based on QUIC, this could have a real impact on anyone involved in streaming.

wolfSSL’s Daniel Stenberg and cURL maintainer, talks to us about HTTP/3 but starts at the beginning with HTTP 1 and 1/1. He outlines some of the issues we had in 1997 such as head-of-line blocking and ephemeral TCP connections. Zooming forward to 2005, HTTP/2 comes on the scene with a single HTTP connection, thus removing the significant overhead of ephemeral TCP connections. HTTP/2 went with a ‘streamed’ connection and could have multiple such streams but one thing that wasn’t solved was head-of-line blocking.

Before moving beyond HTTP/2, Daniel describes the problems that have set in due to ‘ossification’, that is to say that the routers that time forgot which are still on very old, and often buggy TCP implementations. Innovating is very difficult if replacing the TCP within even a subset of boxes would mean I wasn’t able to send my website globally.

Addressing this ‘ossification’ issue, QUIC has stepped in. Developed on UDP instead of TCP QUIC solves a number of problems. First off, moving from TCP to UDP allows the protocol to live in userspace making it easier to update. Working on UDP instead of TCP means that the protocol regains control of the retransmissions allowing for something more efficient than TCP’s strict acknowledgement rules.

So QUIC becomes the transport layer of HTTP/3. Freeing ourselves from TCP, Daniel explains, allows us to remove the TCP head-of-line blocking problem. HTTP/3 on QUIC brings with it faster handshakes and a connection ID. This connection ID allows you to change IP addresses and still maintain your connection which is a significant improvement on what has gone before. Daniel continues by explaining more benefits of QUICK and HTTP/3 such as its encryption and the ability to have multiple streams.

Daniel finishes up outlining eight challenges for HTTP/3. These include the fact that up to 7% of QUICK attempts fail, dealing with ‘fall back’ algorithms, UDP having seen historically low usage and are less optimised as well as the downsides of userland protocol stacks being that it’s harder to get a standard.

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Speakers

Daniel Stenberg Daniel Stenberg
curl master, wolfSSL
main author,

Video: There and back again: reinventing UDP streaming with QUIC

QUIC is a encrypted transport protocol for increased performance compared to HTTP but will this help video streaming platforms? Often conflated with HTTP/3, QUIC is a UDP-based way evolution of HTTP/2 which, in turn, was a shake-up of the standard HTTP/1.1 delivery method of websites. HTTP/3 uses the same well-known security handshake from TLS 1.3 that is well adopted now in websites around the world to provide encryption by default. Importantly, it creates a connection between the two endpoints into which data streams are multiplexed. This prevents the need to constantly be negotiating new connections as found in HTTP/1.x so helping with speed and efficiency. These are known as QUIC streams.

QUIC streams provide reliable delivery, explains Lucas Pardue from Cloudflare, meaning it will recover packets when they are lost. Moreover, says Lucas, this is done in an extensible way with the standard specifying a basic model, but this is extensible. Indeed, the benefit of basing this technology on UDP is that changes can be done, programmatically, in user-space in lieu of the kernel changes that are typically needed for improved TCP handling on which HTTP/1.1, for example, is based.

QUIC hailed from a project of the same name created by Google which has been taken in by the IETF and, in the open community, honed and rounded into the QUIC we are hearing about today which is notably different from the original but maintaining the improvements proved in the first release. HTTP/3 is the syntax which is a development on from HTTP/2 which uses the QUIC transport protocol underneath or as Lucas would say, “HTTP/3 is the HTTP application mapping to the QUIC transport layer.” Lucas is heavily involved with in the IETF effort to standardise HTTP/3 and QUIC so he continues in this talk to explain how QUIC streams are managed, identified and used.

It’s clear that QUIC and HTTP/3 are being carefully created to be tools for future, unforeseen applications with clear knowledge that they have wide applicability. For that reason we are already seeing projects to add datagrams and RTP into the mix, to add multiparty or multicast. In many ways mimicking what we already have in our local networks. Putting them on QUIC can enable them to work on the internet and open up new ways of delivering streamed video.

The talk finishes with a nod to the fact that SRT and RIST also deliver many of the things QUIC delivers and Lucas leaves open the question of which will prosper in which segments of the broadcast market.

The Broadcast Knowledge has well over 500 talks/videos on many topics so to delve further into anything discussed above, just type into the search bar on the right. Or, for those who like URLs, just add your search query to the end of this URL http://thebroadcastknowledge.com/tag/.

Lucas has already written in detail about his work and what HTTP 3 is on his Cloudflare blog post.

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Speaker

Lucas Pardue Lucas Pardue
Senior Software Engineer,
Cloudflare

Video: QUIC in Theory and Practice


Most online video streaming uses HTTP to deliver the video to the player in the same way web pages are delivered to the browser. So QUIC – a replacement for HTTP – will affect us professionally and personally.

This video explains how HTTP works and takes us on the journey to seeing why QUIC (which should eventually be called HTTP/3) speeds up the process of requesting and delivering files. Simply put there are ways to reduce the number of times messages have to be passed between the player and the server which reduces overall overhead. But one big win is its move away from TCP to UDP.

Robin Marx delivers these explanations by reference to superheroes and has very clear diagrams leading to this low-level topic being pleasantly accessible and interesting.

There are plenty of examples which show easy-to-see gains website speed using QUIC over both HTTP and HTTP/2 but QUIC’s worth in the realm of live streaming is not yet clear. There are studies showing it makes streaming worse, but also ones showing it helps. Video players have a lot of logic in them and are the result of much analysis, so it wouldn’t surprise me at all to see the state of the art move forward, for players to optimise for QUIC delivery and then all tests to show an improvement with QUIC streaming.

QUIC is coming, one way or another, so find out more.
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Speaker

Robin Marx Robin Marx
Web Performance Researcher,
Hasslet University

Video: Making Video Streams QUICer

There are many ways to speed up live streaming and much work has gone in to reducing chunk lengths for HLS-style streaming, WebRTC has arrived on the scene and techniques to speed up chunk delivery are in production in CDNs around the world.

But we shouldn’t forget lower down in the detail, we have how the web sites are actually saved to customers – the venerable HTTP. Running on TCP/IP, HTTP packets are delivered using very thorough acknowledgement mechanisms within TCP/IP. Furthermore, it’s immune to spoofing attacks due to a three way handshake to set up the connection.

However, all this communication ads latency as even for low latency connections, these communications can add up to a significant latency and affect the speed of the throughout of the connection.

This talk introduces QUIC which is a replacement for HTTP developed by Google which uses UDP as its underlying delivery mechanism, thus avoiding much of this built-in two way comms.

At the Mile High Video event, Miroslav Ponec from Akamai introduces this protocol which is undergoing standardisation at the IETF explaining how it works and why it’s such a good idea.

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Speaker

Miroslav Ponec Miroslav Ponec
Engineering Director,
Akamai Technologies