Posts Tagged book

Third Edition of the WebRTC Book

WebRTC BookI am very proud of the Third Edition of the WebRTC Book that came out just a few weeks ago.  My co-author Dan and I have been working on it for months, and it is always exciting to launch a new edition!

We worked feverishly during the IETF-89 meeting in London to get all the updates finished – all the APIs, protocols, and standards referenced should be up to date as of then (first week in March).  We also had a lot of fun testing and doing screen captures of the new Demo Application, which now utilizes the WebRTC data channel for Real-Time Text (RTT) between the two browsers.  I’ll write another day about RTT and how much fun it is compared to normal texting or instant messaging in another post.  For us, to make use of the data channel APIs and protocols and show the interoperability between Chrome and Firefox browsers was a lot of fun as well.

16The Demo Application also can now utilize a TURN server for enhanced NAT traversal.  In some circumstances, NATs or firewalls will prevent a direct peer-to-peer Peer Connection from being established between two browsers, and a relay in the cloud is needed.  If the Demo Application fails for you, try reloading the page adding a ?turnuri=1 to the URL and see if it works for you!

Also new for this edition is a description of how to analyze WebRTC protocols on your computer using the excellent open source packet capture and analysis tool Wireshark.  Between Wireshark and various browser tools (try Tools/Developer Tools in Chrome and Tools/Web Developer in  Firefox, or chrome://webrtc-internals in Chrome for lots of useful WebRTC info), you can learn a lot just by playing with WebRTC.  If your application is not working, these tools allow you to debug and analyze what is happening.

Screen Shot 2014-04-02 at 3.40.26 PMFinally, Dan’s introduction to the WebRTC API has been greatly expanded with step-by-step introductions to the various functional parts of the client and server code.  As always, you can download all of our Demo Application code from our book website, and also see it running as well.

We have received so much excellent feedback in the one and a half years since we published the first edition.  We can’t wait to hear from you on what you think of the Third Edition.  We enjoy hearing from you on Twitter, Facebook, or Google+.

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WebRTC Book Giveaway!

WebRTC: APIs and RTCWEB Protocols of the HTML5 Real-Time Web Book CoverWe’re giving away 10 copies of the WebRTC Book!  WebRTC is an exciting new technology coming to web browsers that allows any site to add real-time communication features and capabilities.  Just a few lines of JavaScript is needed to add Skype-like capabilities, and all without any downloads, plugins, or Flash!  Find out why so many people are excited about WebRTC: contact centers, service providers, VoIP providers, OTT providers, and ordinary web site owners.

goodreadsThe giveaway is hosted by goodreads, the social reading site.  If you love to read but haven’t found Goodreads, you should check it out!

From now until November 9, you can sign up to win a paperback copy.  Winners notified on November 10.

Good luck!

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Following WebRTC

WebRTC, Web Real-Time Communications, is a fast moving topic these days!  Here are a few of my suggestions for how to keep up.

First a note about terminology.  Although Google named their open source project webrtc, WebRTC is not just a Google project, it is a major industry initiative involving open Internet standards being developed by many participants.  Don’t confuse these two!

1. Follow Browser Announcements and Releases

Google and Mozilla are the browsers most actively implementing WebRTC today.  WebRTC is available in Google Chrome Beta browser. Download and give it a try for the latest WebRTC extensions.  Some future WebRTC capabilities may be in Google’s Chrome Canary which is the developers preview version of the browser.  To experiment with Mozilla Firefox, you will need to use their nightly build.  Microsoft Internet Explorer and Apple Safari don’t yet have anything available, but you can track their future announcements here and here.

2. Follow the Standards

WebRTC is not just about browser deployments, it is about standard APIs and standard protocols.  To really follow what is going on in WebRTC, you need to track the standards being developed in the W3C and IETF.  This can be a bit tricky, but if you start with the W3C WEBRTC Working Group and the IETF RTCWEB Working Group, that is a good start.

If you have an eReader, try this out.  Here is a link to download the entire set of RTCWEB IETF Internet-Drafts in EPUB format  and here is the set in MOBI format.    Various other sets of IETF documents and RFCs is also available at  The conversion is done using a script written by Tero Kivinen – nice  job!  The formatting of the ASCII art is not 100%, but this is a difficult problem.  The MOBI format worked better for me than the EPUB version, but YMMV.  Perhaps one day the IETF will adopt a friendlier format for Internet-Drafts and RFCs, but I’m not holding my breath!

3. Try WebRTC sites and applications

There are a number of sites and applications already taking advantage of WebRTC features.  One of my favorites is FrisB, a cool new way to think about browser to PSTN communication.  You can find plenty of others by searching the web.  Also, many developers announce and discuss their WebRTC projects on Twitter, so searching with the #webrtc hashtag can find lots of cool things.

There are some interesting blogs out there on WebRTC, including a blog by Tsahi Levent-Levi.

WebRTC: APIs and RTCWEB Protocols of the HTML5 Real-Time Web Book CoverFor background on WebRTC, there are some decent resources.  You might enjoy this video presentation by one of the editors of the W3C WebRTC specification, Cullen Jennings.  If you like books, you might like “WebRTC: APIs and RTCWEB Protocols of the HTML5 Real-Time Web”  written by myself and Dan Burnett, also a co-author of the main WebRTC spec and also the Media Capture and Streams specification.

Best of luck in following WebRTC!  Feel free to share your own favorite ways and links to follow this work.

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WebRTC Interoperability

I’ve spent many years of my career working on interoperability in communication systems.  Back in the dark ages, I did SS7 interoperability testing.  During my CLEC days, I ran a test lab that tested optical, telephony, and ATM/Frame Relay equipment.  I’ve spent many years working on interoperability issues with SIP, starting with the SIP call flows (RFC 3665 and RFC 3666) and then SDP Offer answer (RFC 4317).  I’ve also been to many SIPits (SIP interoperability events run by the SIP Forum), testing voice and video interoperability.

WebRTC poses some interesting interoperability challenges, but I am hopeful we will get it right.

There are four different areas of interoperability: browser, protocol, codec, and offer/answer. Lets go through them one by one.

Browser interoperability is about aWebRTC application or site working the same regardless of which browser the user is using.  In the past browser interoperability was just a browser/server issue, but with the peer-to-peer media and data channel flows of WebRTC, this is now a browser/browser issue.  The good news is that there are only a handful of browsers, so the interop  matrix is not too large.  The bad news is that there are signs of discord already in pre-standards implementations.  For one thing, all browsers must utilize the same APIs, or else WebRTC will be a major headache for developers.  Of course, libraries can hide this complexity from developers, but this will slow down deployment and produces some needlessly bad user experiences.  If we see one browser vendor using their own APIs instead of using the standard ones from the W3C, then we will know that someone is playing company games at the expense of the Internet users of the world.  Hopefully this won’t happen, but it if does, users will and developers will likely move away from that browser.

Protocol interoperability is a major concern for WebRTC.  In the past, browsers didn’t implement many protocols – everything used HTTP (Hyper-Text Transport Protocol).  Today, browsers are doing more, including WebSockets, and will soon move to the next version of HTTP, 2.0.  With WebRTC, the browser RTC Function has to implement multiple protocols including RTP, ICE, STUN, TURN, SCTP etc.  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.  If they don’t the whole industry will suffer.  There are some issues today with the pre-standard WebRTC browser implementations.  For example, one browser today implements a proprietary STUN client that will not work with standard STUN servers.   Browser vendors will need to take protocol interoperability very seriously, and recognize that this is something new for them and that they need to follow industry best practices and approaches.

Codec interoperability is about ensuring that media sessions don’t fail because there is no common codec supported on both ends of the session.  There are so many codecs in use, and every vendor and service provider seems to have their own favorite one.  Fortunately, we should be able to avoid this for audio codecs.  The IETF has recently finalized the Opus audio codec for speech and music, published as RFC 6717 this month.  It really is a fantastic codec, much better than all the rest, making it an easy choice as one mandatory to implement (MTI) codec for WebRTC. Opus is also available as open source.   The other MTI codec is G.711, also known as PCM, which provides interoperability in the VoIP and telephony world, and is also needed for interworking with the telephone network.  Video codec choice is much more difficult.  While H.264 is widely used today, there are no open source implementations or royalty-free licensing available for browsers or implementors.  As such, it is very difficult to see how it could be chosen as a MTI video codec.  Google’s VP8 video codec is proposed as an alternative, and is available in open source.  However, there is much uncertainty about the licensing status of VP8.  Should WebRTC deploy without common video codecs, this again could result in interoperability delays.

Offer/answer interoperability is perhaps the least understood, but most important area.  Offer/answer refers to the negotiation of codecs, parameters, and settings for the media session or data channel between the two browsers.  Even if both browsers use common APIs, standard protocols, and common codecs, if they are unable to successfully negotiate and configure their media or data channel, the connection will fail.  WebRTC uses Session Description Protocol (SDP) to do this offer/answer exchange.  The pre-standard WebRTC implementations are, frankly, a mess in this area.  Their SDP is not standard, and not interoperable with anything else. It will take a lot of work to get this right, and we all must insist that browser vendors support standard offer/answer negotiations.

Occasionally, it is suggested that perhaps offer/answer would be easier if we didn’t use SDP.  We all know and hate SDP, and it is ugly and awkward to use.  However, it has taken over a decade’s work and experience to make it work, and any replacement would likely take that many years to get to work.  And, in addition, since much of the standards-based VoIP and video world uses SDP, it would need to map to SDP as well.  I can’t see this helping interoperability in any way.  Previous efforts to replace SDP failed (anyone remember SDPng?) and I think anyone advocating replacing SDP needs to explain why a new effort wouldn’t meet a similar end, and why this effort wouldn’t take a decade.  Also, the complexities of offer/answer relate to the complexities of negotiating an end-to-end session, and the actual syntax of the descriptions are a very small part of the complexity.

So WebRTC definitely has some interoperability challenges ahead of it.  Fortunately, there are

WebRTC: APIs and RTCWEB Protocols of the HTML5 Real-Time Web Book Cover

WebRTC: APIs and RTCWEB Protocols of the HTML5 Real-Time Web

many experienced engineers who are participating and helping with the effort.  As long as the browser vendors take this seriously and don’t play games, I think WebRTC will have good interoperability, which will benefit web developers and web users alike.

If you are interested in WebRTC, you might like my new book “WebRTC: APIs and RTCWEB Protocols of the HTML5 Real-Time Web” published this month by Digital Codex LLC.

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My New Book – WebRTC: APIs and RTCWEB Protocols of the HTML5 Real-Time Web

WebRTC: APIs and RTCWEB Protocols of the HTML5 Real-Time Web Book Cover

WebRTC: APIs and RTCWEB Protocols of the HTML5 Real-Time Web

Today, I’m excited to announce the publication of my new technical book entitled “WebRTC: APIs and RTCWEB Protocols of the HTML5 Real-Time Web”. The book introduces and explains Web Real-Time Communicatons (RTC), a hot topic in the web and Internet Communications industry right now.

Many of us enjoy services such as Skype, but you have to download the app and install it before you can talk to anyone. WebrRTC browsers have all this built into them – no download, no codecs, no Flash, no plugins needed! This will be really popular with web users. Imagine what Google or Facebook could do with this?

If you are a developer wanting to add voice or video communication to your site or app, in the past it was a complicated business. You needed to write or license a media stack and signaling stack and then integrate them into your own plugin. With WebRTC, you just add a few lines of JavaScript and you are done!

Oh, and I can’t forget gaming! WebRTC allows peer-to-peer data channels to be established between browsers. And again, just a few lines of JavaScript is needed.

If you want to try WebRTC today, it is already in Google’s Chrome Canary (developers version). There are sites out there today live – I’ll share them in future posts. It will be available in most browsers starting next year.

If you want to learn about WebRTC, you might find my book, written with my co-author Daniel C. Burnett from Voxeo), useful. I enjoyed writing it!

Feel free to interact with us on social media, Google+ or Twitter. Comments, suggestions, and opinions are most welcome.

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My Month of Amazon KDP Select

It is just over a month since Amazon announced KDP Select, opening their Kindle Owners Lending Library to independent publishers.  After deliberating the pros and cons, I took the plunge, giving the program a try.  It has certainly been interesting!

Today, Amazon announced the results of the program so far.  First, I’ll share my experience with the program during this month.

After I signed up my techno thriller Counting from Zero, reluctantly saying goodbye to Smashwords, I didn’t have long to wait – the borrows started happening immediately.  After Christmas, I saw another wave of borrows, presumably new Kindle owners.  Then, in the first few days of the month, another surge.  (I presume this means that borrows are done on a calendar month rather than 30 day periods.  If this is true, we will often see lots of borrows at the start of the month.)

In the 3 weeks of December KDP Select was active, for my eBook, borrows represented 18% of Amazon activity (sales plus borrows).  For January so far, the percentage is about 16%, but with higher numbers of both sales and borrows.  I’d estimate overall sales seem to be up about 25% since Christmas.  Since my sales have increased but my sales ranking has not, this seems to be a general trend, at least in my category.  So, looking at my numbers, since the non-Amazon eBooks sales I gave up to participate in KDP Select only accounted for 5% of my total sales, I appear to be ahead of the game, at least in terms of numbers.  But the question was what would publishers get paid for borrows?  Amazon did not commit to any royalty rate when the program was launched, instead saying authors would share a $500,000 pot of money based on borrowing numbers.

Amazon answered that question today in announcing that KDP Select authors will receive $1.70 for each borrow in December, based on 295,000 borrows in December.  For my relatively low-priced eBook of $2.99, this isn’t much lower than my normal royalty for a sale, which is about $2.  I have yet to try out a free book giveaway day, so I can’t share my experience with this aspect of KDP Select, but I hope to soon.

So, one month in, I do not regret my decision to give KDP Select a try.  I see no reason why I won’t renew (re-enlist?) in two more months. However, I am still unhappy about the exclusivity requirement, as are many other independent publishers.  Amazon, if you are paying attention, this requirement just stinks and you should drop it.

How was your month with KDP Select?

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Explaining Security

I spent all last week in Austin, Texas at the Internet Telephony Expo, ITEXPO conference.  In addition to giving the SIP and RTCWEB Tutorial and having a board meeting of the SIP Forum, I moderated a security panel at the 4th Generation Wireless Evolution 4GWE conference.  It was a great panel, with Patricia Steadman, CEO of Telesecret,a company founded by Phil Zimmermann to commercialize the ZRTP media security protocol, and a good friend and former colleague from Avaya, Andy Zmolek from LG Electronics.

As I enjoyed the cool and damp weather back in St. Louis (the opposite end of the weather spectrum from last week!), I was elated to discover that my novel “Counting from Zero” was ranked #12 on Amazon’s Computer Network Security sales list! (Of course, this ranking changes minute-by-minute, so it might very well be ranked a bit lower when you read this.)  I mark this as yet another milestone with this book, my first attempt at fiction.  To have it doing so well in a ranking filled with security text books is very exciting!

I was also thrilled to see two other books I greatly admire ranked just above me at #7 and #9:  The Art of Deception: Controlling the Human Element of Security and The Art of Intrusion: The Real Stories Behind the Exploits of Hackers, Intruders and Deceivers by Kevin Mitnick and William Simon:  I use both these books as references in my book.  I was thinking of Kevin all last week during my travels as I finished reading his newly released memoir Ghost in the Wires: My Adventures as the World’s Most Wanted Hacker.  It was an amazing read, and I highly recommend it.  Maybe I’ll post a full review here one day soon.

My original goal with “Counting from Zero” was to teach the fundamentals of computer and Internet security, but to do it in a non-traditional way.  I had written one other book on security, “Understanding Voice over IP Security”.  Its sales have not been great, compared to some of my other SIP and VoIP books.  One reason is perhaps that security books tend to be dry, and a little theoretical, not well-connected with real life.  In “Counting from Zero” I tried to invent a plot that would not only teach security, but help motivate it.  I set out to create a character, Mick O’Malley, who would initially seem over-the-top in his security, but have the subsequent action and events make him seem more normal, and the rest of us who barely give security a thought the strange ones.

I have greatly enjoyed the reviews of the book, and those complementing my characters, writing, plot, etc.  But I enjoy hearing the most that a reader learned something from the book.

If you have an interest in Internet or computer network security, my book will help explain some basic concepts and help motivate the topic.  If you have ready my book (thank you!) and learned something useful from it (fantastic!), I’d love to hear from you…

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