Welcome to this Protocol Deep Dive course.
In this course,
we'll be focusing on the emerging QUIC protocol that stands poised to take on
much of the work done by TCP over the web and even beyond.
In this module, we're going to do an introduction to QUIC,
which will include the reason why it was invented,
how it's different than TCP,
and we're going to get plenty of hands‑on practice with QUIC in Wireshark.
My name's Chris Greer,
and as a protocol analyst specializing in application troubleshooting,
I'm excited to take you through the first steps in learning this exciting
protocol that's being rapidly deployed over the web.
Get out your copy of Wireshark and download the course trace
files because you will definitely be getting your hands dirty.
First a little bit about QUIC.
If you look up any information on the internet about QUIC,
you might find quickly that it's described as the TCP killer.
Now we're going to chat in a little bit about whether that's true or not.
But for now,
let's get an understanding about what QUIC is and what its purpose is.
Now we can define QUIC, which, by the way,
is not an acronym, as a general purpose,
reliable transport protocol for the web and for other
applications, but over UDP. In short,
QUIC was designed to accelerate web application
delivery and make it more secure.
Now who really uses QUIC today?
Well, chances are you are.
In fact, if you use Chrome,
Firefox, or even Microsoft Edge, all of these support QUIC.
How about on the server side?
Well, you know, just the small guys like Google, YouTube, and Facebook.
Even Cloudflare and many other content delivery
networks are coming up to speed with QUIC.
Other companies, such as Apple, Microsoft,
Amazon, and other players in the game are poised and ready
to flip the switch from TCP‑only delivery of their websites
and services to utilizing QUIC.
But in order to utilize QUIC for the transport,
however,
it requires that both the server and the client both
support it. On the client end, for example,
the Chrome browser has been using QUIC for several years to
retrieve services from Google and other sites,
and many more have followed.
In fact, you just may be watching this course using QUIC over UDP.
So QUIC is here, and it's supporting more and more web applications every day.
But who should learn the QUIC protocol?
Well,
since this protocol is poised to become a huge part of the
way that applications are delivered,
everyone in the IT space needs to have at least basic knowledge about it.
Whether we're a network engineer, in DevOps,
SecOps, or in any form of application development,
we do well to learn QUIC.
After all,
if TCP touches anything about what you do, QUIC will too, if it doesn't already.
So let's go ahead and take a look at our outline for this module in the course.
So we're going to first talk about why is a replacement for TCP necessary?
Doesn't TCP do enough?
Next, we'll talk about the QUIC fundamentals.
We'll go through a history of QUIC.
We'll take a look at the QUIC protocol stack.
We'll look at how is QUIC secured? We'll consider how QUIC recovers
from packet loss. And we'll also talk about how QUIC is the pathway
to deploying and enabling HTTP/3.
Finally, in this module, we're going to get some hands on with Wireshark and a sample trace file of QUIC.