QUIC�

Next generation multiplexed transport over UDP

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Robbie Shade

rjshade@google.com

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video of talk: http://www.youtube.com/watch?v=hQZ-0mXFmk8

Google Developers Live: QUIC

• Multiplexed transport over UDP
• Reduce latency - make the web faster!
• Rapid experimentation
• Open source development in Chromium

QUIC

Quick UDP Internet Connections

Google Developers Live: QUIC

image from Wikipedia (http://en.wikipedia.org/wiki/File:Internet_map_1024.jpg)

Google Developers Live: QUIC

client

client

server

server

Google Developers Live: QUIC

data from httparchive.org

Google Developers Live: QUIC

What about TCP?

• TCP (and TLS) constantly being improved
• Deployment and iteration is slow

• QUIC can be rapidly deployed to clients
• Faster iteration, weeks rather than years...

Google Developers Live: QUIC

What about SPDY/HTTP2?

SPDY/HTTP2 is already a significant step forward,

QUIC is a natural extension of this research.

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Could we do even better if we ran SPDY/HTTP2 over a UDP transport?

Google Developers Live: QUIC

Making the web faster

Two paths to success:

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A. QUIC makes headway on its own, delivers performance improvements

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B. TCP and TLS leverage techniques and lessons learned in QUIC

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Either way, the users win.

Google Developers Live: QUIC

multiplexing

Google Developers Live: QUIC

HTTP pipelining

GET /img.jpg

img.jpg

client

server

Google Developers Live: QUIC

Multiple TCP connections

client

server

Google Developers Live: QUIC

SPDY: multiplexing over TCP

Google Developers Live: QUIC

Head-of-line blocking in SPDY

Google Developers Live: QUIC

QUIC: multiplexing over UDP

Google Developers Live: QUIC

No head-of-line blocking in QUIC!

Google Developers Live: QUIC

latency

Google Developers Live: QUIC

table adapted from High Performance Browser Networking (Grigorik 2013)

Google Developers Live: QUIC

image from High Performance Browser Networking (Grigorik 2013)

TCP: 1 round trip

Google Developers Live: QUIC

image from High Performance Browser Networking (Grigorik 2013)

TCP + TLS: 3 round trips

TCP

TLS

request

Google Developers Live: QUIC

Google Developers Live: QUIC

TCP

TCP + TLS

QUIC

100 ms

200 ms

300 ms

0 ms

100 ms

1. Repeat connection

2. Never talked to server before

1

1

2

2

Google Developers Live: QUIC

Encryption

Comparable to TLS

Perfect forward secrecy, with more efficient handshake

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Replay attack protection

single-use cryptographic nonce

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IP spoofing protection

signed proof of address

more crypto details...

Google Developers Live: QUIC

Forward Error Correction

Google Developers Live: QUIC

Packet Pacing

Google Developers Live: QUIC

“Parking lot problem”

Google Developers Live: QUIC

Deployment

• QUIC in development over the past couple of years
• Expanding our experimentation... benchmarks to come
• Try it today in Chrome!

Google Developers Live: QUIC

QUIC in Chrome Dev/Canary

SPDY/QUIC Chrome indicator extension

enable QUIC: chrome://flags/#enable-quic�

inspect QUIC: chrome://net-internals#quic

Google Developers Live: QUIC

QUIC

• All the benefits of SPDY (multiplexing, priorities, etc.)
• 0-RTT connections
• Packet pacing
• Forward error correction
• Adaptive congestion control (friendly to TCP)
• Encryption equivalent to TLS
• Chrome can talk QUIC to Google today

Multiplexed, encrypted transport over UDP

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Google Developers Live: QUIC

QUIC�

Source: QUIC in Chromium

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Further reading: Design doc and rationale, Wire spec, Crypto doc

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Mailing list: proto-quic@chromium.org

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Robbie Shade

rjshade@google.com

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​

video of talk: http://www.youtube.com/watch?v=hQZ-0mXFmk8

Google Developers Live: QUIC