WebRTC Conference and Expo 2012: Mapping SIP to WebRTC - a misunderstanding?

I was fortunate enough to attend the first WebRTC Conference and Expo in San Francisco last month.  This fascinating conference demonstrated the growing hype and interest around WebRTC.

One of the things I observed at the conference was a lot of discussion about "WebRTC obsoleting SIP" and "mapping SIP to WebRTC", both topics that seemed to indicate a misunderstanding of both SIP and WebRTC amongst those discussing them.

SIP and WebRTC are very different protocols (in fact WebRTC is a set of protocols).  SIP relates to the signalling plane and WebRTC to the media plane.  This means that SIP and WebRTC are complementary protocols not competing protocols.

There was a lot of discussion about WebRTC's ability to establish media sessions without signalling or server infrastructure - this is not possible.  When you use the PeerConnection API in a browser you get and provide SDP which needs to be exchanged by the peers to establish the media connection.  How can the peers exchange this SDP without signalling or server infrastructure?

It is clear that some signalling and server infrastructure is required for WebRTC, and this can take one of three obvious forms:

• Proprietary HTTP/REST signalling
• XMPP/Jingle over WebSocket
• SIP over WebSocket

Each of these has advantages and disadvantages.  HTTP/REST signalling is very simple but as HTTP is a transaction (not a session protocol) dialog state must be maintained within the network - this could easily result in resiliency and scaling issues, or complex server infrastructure that replicates dialogs between servers.  XMPP/Jingle is a session protocol, but like HTTP/REST it is lacking in terms of support for common regulatory and privacy features[1].  SIP in many ways is the ideal protocol - the hint is in the name, "Session Initiation Protocol" - as well established extensions (such as outbound) provide resilience and scaling, while regulatory and privacy issues have long been catered for.

Some people indicated that they believed that the use of SIP with WebRTC would be limited due to its complexity and the unwillingness of web-developers to use it.  However, I am not entirely convinced by this argument.  A web-developer is unlikely to want to implement any of the signalling necessary for his WebRTC application, but he will make use of any good libraries that are available.  I believe that SIP will be extensively used in WebRTC applications as long as a good enough set of libraries are available so that web-developers do not need to deal with it directly.

[1] A lot of web-developers ignore regulatory and privacy requirements simply because the large OTT companies have not had to do anything yet.  "Yet" is the operative word here - regulations and privacy are important and cannot be ignored indefinitely.  Using a protocol like SIP for the signalling future proofs web apps and services.  With a good SDK using SIP for the signalling is no harder than using anything else.

Geeky t-shirt

I am off to FOSDEM 2011 at the end of this week and a geeky trip would be nothing without a geeky t-shirt.  Unfortunately, geeky t-shirts are expensive.

One of the guys at work came up with a good idea though, so I am currently preparing to make my own geeky t-shirt.  This is the image I will iron onto it:



Any guesses what it is and what it means?

My new job (Crocodile RCS)

It's been a while since I wrote anything here.  This is mainly due to the fact that I rarely feel I have anything of interest that is worth sharing with the world.  However, in the unlikely event anyone bothers to read this, I thought I should mention that I have just finished the second week at my new job.  This is a big thing for me as I had been working for my previous employer (Telsis Ltd) for over ten years and it was my first job since graduating from university.

I am now working for a start-up company called Crocodile RCS Ltd (http://www.crocodile-rcs.com/ for those interested in what it does).  The first week at my new job was nothing short of hectic as it began with a 4am wake up call (a taxi to Heathrow airport collected me at 5am) on Monday and ended after 12:30am on Saturday (a taxi from Heathrow airport dropped me off).  On the plus side I got to add another country and city (Russia and Moscow) to my long list of work sponsored "holidays".

While less hectic than the first week my second week has been nothing short of busy.  While not (yet?) working the ridiculous hours you sometimes hear associated with start-ups the days have still been quite long, and the stunning part has been how quickly they seem to go by.  The best part, from my point-of-view (I admit I am a glutton for punishment), is that there is so much needing done that it is simply not possible to get everything needed done completed each day.  Of course this means there is a lot of prioritising going on, but it does have the upshot of meaning I never get a chance to be bored.

Why have a blog and never post?

Well, the main reason, is that I usually don't have anything of interest to post.

However, right now I am on vacation in Boston.  I flew out to the US on Saturday a couple of weeks ago (12/04/2008) to attend SIPit 22 (up in Durham, NH) with two colleagues from my work - I must say that the environment up in New Hampshire is wonderful, I believe I am unlikely (for a number of reasons) to ever want to live in the US, but if I had to it wouldn't be too bad if it were up in New Hampshire.  My colleagues flew home last Saturday but I have stayed out an extra week, and it seems like (based on the weather alone) a good week to spend out here.

The only disappointment I have had so far is sunburn on my face and ears (guess which genius went out whale watching on the hottest day of the year without using any sun-cream or wearing a hat), the Prudential Tower (or Towah, as the door man called it) observation deck being closed, and a bit of queasyness cause by my decision to skip breakfast and lunch and then go on the Samuel Adams Brewery Tour (with free beer at the end of it).  I highly recommend the Brewery tour, it is free and the beer is excellent.

I have put the pictures from my vacation (so far) online.  There are a lot of photographs there, but I am particularly pleased with some of them (especially some of the ones from the whale watching and some of those taken in the New England Aquarium).

 My SIPit 22 and vacation pictures are located at: http://gallery.dunkley.me.uk/v/pd/SIPit/SIPit22/

SIPit 21, Beijing, November 2007

I attended SIPit 21 in Beijing (November 2007).  Pictures of the event (and some touristy stuff I did afterwards) are available at http://gallery.dunkley.me.uk/v/pd/SIPit/SIPit21/