Quality Assurance for WebRTCServicesMarch 2016, Kranky Geek India

Tsahi Levent-Levi

People don’t usually test their WebRTC implementationsSeriously

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And when they do, they test things manually

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Testing and automation are mandatory and widely usedMeanwhile, on other software fields…

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How do you go about automating your WebRTCtestbed?7 suggestions for you

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W. Heath Robinson

• WebRTC changes… monthly

• You have more than a voice callto test

Rely on the browser

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Chrome

Firefox

Selenium is your friend

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Rely on the browser… and peer into the future

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Stable What your customers are using

Beta What you should expect in the next release

DevWhere you can complain about breakage – and expect fixes in time

Canary A nightly build of whatever is available at that moment in time

Testing only against the Stable version of browsers means you find out issues only after the service breaks for your customers.

> ffmpeg -i MYFILE.mp4 -pix_fmt yuv420p

> sed -i '0,/C420mpeg2/s//C420/' *.y4m

> google-chrome --use-fake-device-for-media-stream

--use-file-for-fake-video-capture=MYFILE.y4m

See http://testrtc.com/y4m-video-chrome/ for more details

Handle your media feeds

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and think about the type of content you need2

For some arcane reason (called AGC or something), browsers will loop your fake video but won’t look your fake audio

Loop an input 6 times (=expand 5 minutes to 30)> ffmpeg -f concat -i <(for i in {1..6}; do echo "file '$PWD/INPUT.wav'"; done) –c

copy OUTPUT.wav

> google-chrome --use-fake-device-for-media-stream

--use-file-for-fake-audio-capture=OUTPUT.wav

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2 Handle your media feedsand make sure your audio recording is suitably long

Take care of the network

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Use netfilter.org iptables

Network Impairments

• Bitrate limitation• Packet loss• Jitter & latency

Firewall Configuration

• None• Force TURN relay• HTTP only• HTTPS only

Multiple Locations

• Virtualization sucks• Stability & Throughput

is what you need• Explore barebone

options

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• Caller / Callee

• Caller / Agent

• Caller / Expert

• Meeting point

• Conference

• Webinar

Handle synchronization

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Can you see the problem?

Visualize the results

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Visualize the results

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Chrome 48 with VP8 Chrome 49 with VP9

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Are these real network issues with packet losses or bugs in these products and how they report packet loss?

Visualize the results (2)

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• How much time does it take to connect the session?

• Are the media channels you need really there?

• Are you sure there aren’t any “additional” media channels?

• Is the bitrate following your restrictions?

Don’t forget to set your expectations

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You never know when things will become handy…

Here are a few thoughts:

• chrome://webrtc-internals dump

• Browser console logs

• Media recordings

• Machine performance

Collect EVERYTHING

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Don’t take WebRTCtesting lightly

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Thank YouTsahi Levent-Levi

http://bloggeek.me

tsahil@bloggeek.me

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