Chris Kranky

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Amazon Chime with WebRTC

Yes, Amazon Chime is using WebRTC. Here's a few early interesting tidbits on the behind the scenes.

Chris KoehnckeChris Koehncke

Amazon announced their Chime service/application today which offers an audio/video conferencing service with an orientation to enterprise customers. Amazon has been working towards more user level enterprise services with the introduction of WorkDocs (a swipe at and WorkMail (trying to take on

However, this is (to my knowledge) the first real user-facing application that AWS has introduced. I undertook a quick review. At first glance, it’s hard to tell who AWS is swiping at? Chime isn’t as fully featured as GoToMeeting or WebEx. It’s not got the chat functionality you’d see in Slack and the audio/video capabilities won’t likely scare or Skype sufficiently. So Chime is neither fish nor fowl at the moment.

Nonetheless, it’s a start and it’s a marker on the table to say AWS is playing in the collaboration space. My first impressions are mostly positive.

amazon-chime-624x351The most interesting aspect of Chime is it wants to run all the time (foreground or background). Unlike a typical WebEx session where you join and leave. Chime is positioning where you can be notified to join a session. This should be a warning shot across the bow of traditional Unified Comms suppliers.

The WebRTC Detective Team is on the case but early indications are YES, AWS Chime is using WebRTC. Chime is not browser application and instead is downloadable executable.

I have my best people on it, but for the moment it appears to be using the WebRTC core library and utilizing VP8 as the video codec, audio quality is high and appears to be Opus. Interesting, AWS has implemented some strict bandwidth controls, Chime won’t use more than 600 kbps no matter how many parties join a video.

Chime also was careful not to crush my CPU (a oft problem with WebRTC applications gone bad), even with 5 people in a call my Mac Pro Energy Impact never went > 130 and on typical calls was been 100 – 115.

Is Chime using an SFU (selective forwarding unit) or MCU (multi-control unit) for the video? It’s hard to say, virtually everything is encrypted so we watched the behavior of the data streams. In short, the current WebRTC police conclusion is the platform is an MCU (meaning it mixes the video) and perhaps AWS is using a heavily modified version of FreeSWITCH.

Chime has a screen/application window sharing feature (which is not using WebRTC). Note: You can join a Chime session using nothing but a browser, but you can only view the shared screen (no audio or video). Couldn’t figure that one out.

Does this matter? Yes and no. An MCU mixes the video in a central server and this typically limits layout controls to a single view per session. What does that mean? For example, say you want to see “Tom” full screen and Sally wants to see “Harry” full screen, you generally can’t have this flexibility with an MCU video mixer. With a SFU technology each party has control over the video segments they are receiving.

Chime is based upon Biba Systems technology which AWS quietly acquired in November 2016. sf based Biba had raised just over $15m since it’s founding in 2013.

While the app looked nice, the end pricing is less so. The $15 a user for the Pro is quite a widespread from the $2.50 Plus package. Hard to tell what AWS wants you to buy. There is a corresponding mobile app, which worked, but quite basic.

There were some ‘nits’ I found with the product though. Chime supports traditional PSTN dial-in (remember that) but is charging a per-minute rate for this. Conference IDs to join a PSTN call have more digits than a nuclear rocket launcher. You can record the sessions but it’s only the audio (no video recording). The ability for other parties to mute each other led to some confusion in my test calls (why am I always getting muted?). Finally, the lack of any moderator functions (like the ability to ‘boot’ someone) means it best for team communications.

AWS Chime is in the collaboration market now and no doubt simply sitting on the shelf is enough to gain them some customer traction. Great to see another WebRTC app into the market place. While this first product isn’t terribly well powered, it may be good enough for some applications and competition have to be wondering what’s next for AWS to launch in this space.