WebRTC World Feature Article

September 25, 2012

WebRTC Poses Several Ineroperability Challenges


In a recent post on his blog “Counting From Zero,” Internet communications expert Alan B. Johnston focused on some interoperability challenges confronting WebTRC. While addressing these problems, Johnston was hopeful of overcoming them.

The four key interoperability issues WebRTC must tackle today are browser, protocol, codec and offer/answer.  Johnston’s blog tackles each one separately, one after the other.

Regarding browser interoperability, Johnston wrote that a WebRTC application or the site must work the same way regardless of the type of browser being used.  Because there are only a handful of browsers, the interop matrix is not too large, according to the blogger.

However, there are signs of discord in pre-standards implementations.

To tackle such an issue, Johnston’s blog suggests all browsers must utilize the same APIs or else WebRTC will be a major problem for developers. Although, the libraries can hide this complexity from developers, but it will slow down deployment and could also result in a poor user experience.

Consequently, if one browser vendor intends to use its own APIs instead of the standard from the W3C consortium, the browser company is playing games with Internet users of the world, according to the blogger.

Anyway, Johnston hopes users and developers will likely stay away from such browsers.

Likewise, with respect to protocol interoperability, Hyper-Text Transport Protocol (HTTP) was the most popular protocol in the past. But today, browsers are doing lot more, including WebSockets, and will soon move to the next version of HTTP 2.0.

Plus, with the emergence of WebRTC, the browser RTC function has to implement multiple protocols including RTP, ICE, STUN, TURN, SCTP etc., according to the description presented by Johnston.

As a result, wrote Johnston, “These protocols define ‘bits on the wire’ and ‘state machines’ that ensure that interoperability works.”

For browser-to-browser media and data channels to work, browsers must implement these protocols and carefully follow the standards.

The blog also sheds some light on the codec interoperability, which is about ensuring that media sessions do not fail because there is no common codec supported on both ends of the session.  To address the codec issue, Johnston’s blog recommends IETF backed Opus audio codec for speech and music, published as RFC6717.

Lastly, with regard to offer/answer interoperability, referring to the negotiation of codecs, parameters and settings for the media session or data channel between the two browsers, the blogger cautions about the difficulties of using Session Description Protocol (SDP).

However, no alternative solution was recommended, leaving the challenge of addressing offer/answer interoperability issue with W3C consortium. 

Want to learn more about the latest in communications and technology? Then be sure to attend ITEXPO West 2012, taking place Oct. 2-5, in Austin, TX. Stay in touch with everything happening at ITEXPO. Follow us on Twitter.




Edited by Braden Becker




Comments powered by Disqus