So now,
for the last concept that we're going to cover in this module
is we just want to make sure we're clear on the difference
between QUIC packets and QUIC frames.
So let's stay in this trace file.
This is going to be Lab3, and we're going to go into packet number 10.
This is just a good place to show this to you. And we're
going to use this packet because in it,
we can actually see two QUIC IETF packets.
You see that in packet number 10?
So I'm going to select that, and we see Ethernet,
IP, UDP, Datagram, and now I've got two QUIC packets.
Now, let's go ahead and open those up and see what's contained within them,
so let's look at the first one.
So this is a QUIC packet.
This is where we have connection information,
so that's some of that packet overhead, and this,
technically, down here, this TLS 1.3, technically,
this is a frame, so this is data within the packet.
And if I expand this out, I can see that this is a frame type CYRPTO.
So QUIC is saying, hey, here's a packet,
and within it, I have got a CRYPTO frame,
and this is actually the finished aspect of the TLS 1.3 conversation.
So that's one.
Now, I could have other frames in this packet.
I could see maybe I have a stream data or I have further handshake information,
that all could be in the same packet; however,
here, I just see one frame in one packet.
Let's go ahead and collapse this packet.
I want to take a look at this other one.
Now, in this one, this is a totally separate packet.
In here, I've got different Header values, right, so this is a Short Header.
It's for the same connection,
so our source and destination connection information didn't change.
But in this one, we're using a Short Header.
And the frame type that we have here, so this is an ACK frame in a QUIC packet.
So I had to define the packet attributes,
and then I could include the frames within that packet.
If we want to see one that's a little bit more busy,
let's go ahead and go down to packet number 11 in our trace,
and here, we can see, I just have 1 packet,
so a single QUIC packet,
and that encompasses all of these HTTP/3 frames and all that data.
So let's go ahead and expand that,
and this we're going to see our Connection information,
our Short Header. But now, as soon as I start seeing these STREAMs,
so STREAM, STREAM, STREAM, STREAM, there's four STREAM frames, now,
keep in mind, this STREAM is defined and then Stream Data, if STREAM is defined,
Stream Data, defined, Stream Data.
Now,
what Wireshark does is it just takes that data, it dissects it
since we have the proper key information,
and then we can see that down below,
it actually builds that out for us. So this is where we can start
to see the specific header information, the payload, this is where
we can see, do we have Stream Data?
Okay, so, again,
a QUIC packet has that Header, Frames within the packet are all
defined, and typically, those are STREAM frames, or HANDSHAKE frames,
or CRYPTO frames, so we've got to make sure that we have those concepts pretty well in mind going forward.