Posts categorized "VoIP"

Audio Recording: My SIPNOC 2014 Talk - "Is It Time For TLS For SIP?"

Is it time to use Transport Layer Security (TLS... essentially what we used to call "SSL") to add a layer of trust and security to Voice-over-IP (VoIP) that uses the Session Initiation Protocol (SIP)?

Way back in June 2014, I gave a talk on this topic at the SIP Network Operators Conference (SIPNOC) in Herndon, Virginia. I recorded the audio of the session... but then lost track of the recording. I recently found it and, since much of it is (sadly) still relevant, I decided to release the recording as one of my The Dan York Report audio podcast episodes:

The slides that go with the presentation are available on SlideShare:

You'll see in the slide deck that I also provide some tutorials around DANE and DNSSEC along the way.

Coincidentally, I learned on Facebook over the weekend that my friend Olle Johansson was speaking on this exact topic at the FOSDEM 2016 conference in Brussels this weekend. His slides about SIP & TLS are also available on SlideShare, and he has more recent information - and also the conclusion that we need to use "SIP Outbound" for any of this to work:

Olle's last slide about what we need to do hits on the key points - and I agree with his conclusions.

Let's look at how we can get more TLS used within SIP to bring about a more secure and trusted VoIP infrastructure!

Talko's Purchase By Microsoft Shows The Challenge Of The Directory Dilemma

Today Microsoft announced that they acquired the technology of Talko, a communication app created by Ray Ozzie and launched back in September 2014. Fortune has an article on the acquistion, as do a good number of other media sites.

After Talko first launched, I wrote about my initial experience - and the problem I had of Talko working through my home firewall. But I was intrigued by the possibilities laid out in a Medium article about how Talko could change communication and integrate voice, chat and messaging in interesting ways.

The reality, though, was that Talko was a classic case of suffering from the Directory Dilemma - as I said in that article:

People will only USE a communication application if the people they want to talk to are using the application.

And that was true for me... I tried out Talko, as I try out many apps. I used it for a while. And then... I stopped.

The people with whom I communicate were not regularly using Talko.

You can see the recognition of this dilemma in today's front page of Talko's web site:

However, as engaged as many of you have been, the reality is that the broad-based success of communications apps tends to be binary: A small number of apps earn and achieve great viral growth, while most fall into some stable niche.

For all the value and enjoyment it's delivered, and for all the team's listening and perseverance, Talko was largely on the path to filling a (passionate) niche. We're in this to have great impact, so it's time for a change.


We deeply appreciate the commitment that so many of you made in betting on Talko. You invested your time and your reputation to convince your friends and co-workers to use the product with you.

This is the reality that messaging / communication apps have to face today. Either somehow build that massive directory - or be happy (and financially stable) within the certain niches and communities in which your product can thrive.

What's next for the Talko team (minus Ray Ozzie, who has said he will not be re-joining Microsoft) isn't 100% clear. Both the Microsoft and Talko posts today are vague, with the latter saying:

As part of the Skype team, we'll leverage Talko’s technology and the many things we’ve learned during its design and development. We'll strive to deliver the best of our product’s innovations far more broadly than on our current path.


Looking forward, we hope to hear from you again as we find ways to deliver the best of Talko in Skype.

We'll have to see what pieces of Talko they bring into Skype.

Congrats to Ray Ozzie and the Talko team - and to Microsoft - on this acquisition. I hope it does work well for all involved.

Meanwhile, we can look and wonder which of the zillion new messaging apps out there will be the next to fold into a larger player...

P.S. There's a thread on Hacker News about today's announcement and there was a really long thread on HN back in 2014 when Talko was announced that may still be of interest.

Video and Slides Now Available For My AstriCon 2015 Keynote: Open Source and The Global Disruption of Telecom

If you're interested in what I said last month at AstriCon 2015 in my keynote on "Open Source And The Global Disruption of Telecom: What Choices Will We Make?", the video and slides are both available.

As I wrote about previously, the context for this discussion was to talk about the changes that are happening all around us in terms of the ways in which we communicate. Here was the abstract:

There is a battle raging for the global future of telecommunications and the Internet. Taking place in networks, board rooms and legislatures, the battle will determine how we all communicate and what opportunities will exist. Will telecom support innovation? Will it be accessible to all? Will it give us the level of security and privacy we need to have the open, trusted Internet? Or will it be restricted and limited by corporate or government gatekeepers?

The rise of voice-over-IP has fundamentally disrupted the massive global telecommunications industry, infrastructure and policies. Open source software such as Asterisk has been a huge driver of that disruption and innovation.. but now what? What role do platforms such as Asterisk play in this space? And what can be their role in a telecom infrastructure that is now mobile, increasingly embedded (Internet of Things) and more and more using proprietary walled gardens of communication?

How well I delivered on that will be up to you to decide... but I felt good about how it all came out and received many great comments and feedback throughout the rest of the event and afterwards. And, as a speaker I could see from the crowd (about 500-ish people) that they were NOT looking down into their smartphones or laptops... which is always a good sign! ;-)

A key point of what I aimed to do was to bring people up to a higher level to think about how their own actions fit into the broader context of what is happening in the world today.

It was fun to do! And I loved all the questions I was getting after that. My goal was to make people think... and it seemed that at least for some I did.

My part of the video starts after 15 minutes of introductory items (this was the opening of the event), so if you watch in the embedded video below you'll need to move forward to the 15:00 mark. You can also follow this direct link to the start of my segment with an introduction to me from Mark Spencer, the creator of Asterisk.

(And yes, this was the first time I had ever given a presentation wearing a ponytail in the long hair experiment I've been trying this year... I'm still not 100% sure I'm going to keep this style. This may be the first and only presentation you see with me like this.)

Unfortunately, the video only shows me talking on stage and doesn't show the slides I was using... so you don't understand what I'm talking about when I reference the slides.

I've posted the slides to my SlideShare account but as you'll see without the video or audio they aren't of much value. This was a wonderful opportunity for me to present in the very minimalist style I prefer where I only use images or a few words - and I thoroughly enjoyed doing so.

However, syncing the slides to the video is not something you'll probably find easy. At some point perhaps I'll create another video showing both my speaking and the slides... but I don't know that it will happen anytime soon.

Meanwhile, here they are...

Some of the links I reference in the presentation include (in the order of their appearance):

If you enjoyed this presentation and would like to have me potentially speak at your event, please do contact me. I've been speaking for many years and very much enjoy giving these kind of presentations at all types of events.

Keynote at AstriCon on Oct 14: Open Source And The Global Disruption Of Telecom - What Choices Will We Make?

Astricon danyork 660px

Two weeks from today I'll be in Orlando giving the opening keynote address at AstriCon 2015. The abstract of the session is:

Open Source And The Global Disruption Of Telecom - What Choices Will We Make?

Wednesday, October 14th, 2015 - 9:00 am to 9:45 am - Pacifica Ballroom 7

There is a battle raging for the global future of telecommunications and the Internet. Taking place in networks, board rooms and legislatures, the battle will determine how we all communicate and what opportunities will exist. Will telecom support innovation? Will it be accessible to all? Will it give us the level of security and privacy we need to have the open, trusted Internet? Or will it be restricted and limited by corporate or government gatekeepers?

The rise of voice-over-IP has fundamentally disrupted the massive global telecommunications industry, infrastructure and policies. Open source software such as Asterisk has been a huge driver of that disruption and innovation.. but now what? What role do platforms such as Asterisk play in this space? And what can be their role in a telecom infrastructure that is now mobile, increasingly embedded (Internet of Things) and more and more using proprietary walled gardens of communication?

Join the Internet Society's Dan York in an exploration of what the future holds for telecom infrastructure and policy - and how the choices we make will determine that future.

Sounds great, eh?

Now I just have to deliver on that lofty rhetoric! :-)

Seriously, though, I'm very much looking forward to giving this presentation and I'm delighted that the folks at Digium asked me to speak. We're at a critical time in the evolution of our global communications infrastructure... with everything moving to IP and also moving to mobile, there are incredibly important choices we have to make for our future.

In the talk, I'll be speaking about the scenarios we have for what our future Internet could look like. I'll be talking about the role of open source. I'll be challenging the audience with some questions to ponder. I'll touch on some of the incredibly important - yet hard to understand - global policy issues such as the upcoming WSIS+10 Review in December - and why an open source developer should even remotely care! I'll of course hit on security issues and the rise of mobile... and more...

I'm excited!

I'm also excited to finally attend an AstriCon event. I used to write about Asterisk a good bit and for a while was running my own server in my home office for VoIP... but in all that time I never was able to work in attending an AstriCon!

If you are going to be there in Orlando, please do say hello! (There's still time to register!)

P.S. And yes, Olle Johansson, I'll be sure to work in at least one reference to IPv6! And TLS, too! Don't worry! :-)

Firechat Enables Private Off-The-Internet (P2P) Messaging Using Mobile Phones

Firechat mesh network

There was a fascinating article posted on Medium this week by the CTO of messaging app Firechat:

In the text he outlines how they do decentralized "off-the-grid" private messaging using an ad hoc mesh network established between users of the Firechat app. It sounds like the app instances join together into some kind of peer-to-peer (P2P) network and then do normal "store-and-forward" messaging.

Of note, the apps do NOT need an Internet connection, or even a cellular network connection - instead they can use the Bluetooth and WiFi radios in the mobile phones to create a private mesh network and connect to other users of the Firechat app.

Naturally, having spent some time exploring P2P networks back when I was playing around with P2P SIP and distributed hash tables (DHTs) and other technologies, I immediately jump into the techie questions:

  • How are they routing messages from one user to another?
  • How is the "directory" of users in P2P mesh maintained?
  • What addresses are they using for the communication? Is this still happening over IP addresses? Or are they using some other kind of addressing?
  • How do users join and leave the mesh network?
  • How do user get authorized to join the private mesh? (Or is it just open to all?)
  • How secure is the communication between the parties?
  • Is the message encrypted or private in any way? Or is it just plain text?
  • How well do smartphone batteries hold up if multiple radios are being used? What is the power impact of joining into a mesh network like this?

None of that is covered in this article, of course... this piece is more about the theory of how this can work given a particular density of users. It introduces the phrase "percolation threshold" and provides some background and research into how these kind of networks can be created.

I've always been fascinated by P2P networks like this sounds to be. The beauty of the Internet... the "Internet Way", so to speak... has been to support distributed and decentralized architectures.

If you think about mail or web servers, they are (or at least were) massively distributed. Anyone could set up a mail or web server - and millions upon millions of them bloomed. While we've certainly seen a great amount of centralization due to market dominance (ex. Gmail), the architecture still is distributed / decentralized.

Except... of course, the directory is still centralized. Mail and web servers rely on the central directory of DNS to resolve domain names into IP addresses so that connections can occur. Most other applications rely on DNS for this as well.

Hence my curiousity about how Firechat is handling the directory and routing issues.

I'm also intrigued by how the article hints at integrating Internet-connected users into the P2P mesh. So you really have a hybrid network that is part P2P and part connected out to cloud-based servers.

(And all of this brings me back to those early days of Skype 8-10 years ago when so many of us were captivated by the P2P mechanisms they created... most all of which is now gone in the post-Microsoft-acquisition as Skype has moved from P2P to server/cloud-based - with one big reason being given that mobile devices apparently had speed and battery life issues participating in true P2P networks.)

A key challenge Firechat faces, of course, is the "directory dilemma" of building up the quantity of users where P2P mesh networks like this can happen. This is the same dilemma facing basically all over-the-top (OTT) messaging apps. "Percolation theory" requires a certain user density for a mesh like this to work.

That will be their struggle.

And in some urban areas I can see this working quite well. Perhaps not so much out in the woods of New Hampshire where I live!

But I wish them well with this. I love to see new explorations of potential new architectures for communication. And I can certainly see instances when ad hoc, distributed/decentralized P2P meshes like these could be quite useful.

And I'm definitely looking forward to some more technical articles that dive down into some of these questions.... I do hope they'll write more soon!

Photo credit: Stanislav Shalunov's article about Firechat

WebRTCHacks Publishes Analysis of Facebook and WhatsApp Usage of WebRTC

WebrtchacksThe team over at webrtcH4cKS (aka "WebRTCHacks") have been publishing some great articles about WebRTC for a while now, and I thought I'd point to two in particular worth a read. Philipp Hancke has started a series of posts examining how different VoIP services are using WebRTC and he's started out exploring two of the biggest, Facebook and WhatsApp, in these posts:

Those articles are summaries explaining the findings, with much-longer detailed reports also available for download:

Both of these walk through the packet captures and provide a narrative around what is being seen in the discovery process.

A common finding between both reports is that the services are not using the more secure mechanism of DTLS for key exchange to set up encrypted voice channels. Instead they are using the older SDES mechanism that has a number of challenges, but, as noted by the report, is typically faster in enabling a call setup.

All in all the reports make for interesting reading. It's great to see both Facebook and WhatsApp using WebRTC and I think this will only continue to help with the overall growth of WebRTC as a platform. As an audio guy, I was pleased to see that Facebook Messenger is using the Opus codec, which is of course the preferred codec for WebRTC... but that doesn't necessarily mean that it has to be implemented by companies using WebRTC within their own closed products. Kudos to the Facebook team for supporting Opus!

Thanks to Philipp Hancke for writing these reports and I look forward to reading more in the series!

Wire Launches WebRTC Voice/Chat Web App For Windows, Linux, more - Includes High TLS Security

Yesterday the team over at Wire launched a new WebRTC-based "Wire for Web" app that lets people on Windows, Linux or any other platform now communicate with people using Wire on iOS, Android or OS X. You can get to it simply at:
If you already have an account you simply sign in with your credentials. If you don't have an account you can easily create one.

I've been running both the native Mac OS X client and the web client for a bit now (I was part of web beta program for Wire) and it is truly amazing how well the team has made the web experience to be seamless between the web and native client. Here's a screenshot showing both side by side (click/tap for a larger image):

Screenshot wire for web

In the web view on the right you have the browser bars at the top and one of the images did not go the full width of the column, but otherwise the experience and visual display has been essentially identical between the two platforms. The synchronization between the two is nearly instantaneous and all the features work really, really well.

Notifications in the web browser (if you allow them) work great to alert you to new messages.

And the voice calls from within the web browser have the same outstanding audio quality I've come to expect from Wire.

All in all the web implementation is quite excellent.

This new web app also addresses a concern I had from the initial launch of Wire back in December - the lack of a client for users on Microsoft Windows. With this web app Windows users - and Linux users - can now equally participate in communication over Wire. This is all courtesy of WebRTC that allows modern browsers to be able to use voice and chat from directly within the browser. Wire co-founder and CTO Alan Duric published a post about how they use WebRTC.

Alan also clued me in to the strong degree that the Wire team takes security extremely seriously. In fact I would say they take it more seriously than many other similar web apps I've seen. If you go over to Qualys SSL Labs and plug in "" you get a result of an "A+":

Ssllabs app wire com

The same can NOT be said of other similar web interfaces that I tested from similar services.

I've been writing about Wire for a bit now (see my various articles) and I have it running on my Mac all the time, primarily because of the great value I get out of a couple of group chats that I am in. From a chat / messaging perspective it's one of the best I've seen and I find it extremely useful.

Curiously, I don't find myself using Wire as much for actual calls, primarily because I find that much of my interaction has moved to video calls, and Wire doesn't support those yet. When I do use Wire the audio quality is truly amazing, but that has to do with the audio pedigree of the team behind Wire, and the fact that they are using the Opus codec. On a larger level, there is also the continued "directory dilemma" that I've written about, namely that Wire has the same struggle as most other new tools in that you need to gather a strong "directory" of people who are actually using the app for it to be an app that people regularly use. Most of the people with whom I regularly communicate aren't users of Wire ... yet.

Still, the release of this "Wire for Web" gives me hope that Wire may be able to build some momentum now that, for example, Microsoft Windows users can now join in. Time will tell... but this will definitely help!

Kudos to the team at Wire for this very excellent web release?

P.S. If you are using Wire, or try it out, you should be able to find me on Wire as "Dan York".

Note: an audio podcast about this topic is also available:

WhatsApp Calling Arrives on iOS - More Telecom Disruption Ahead!

Whatsapp callingAs I checked my AppStore updates on my iPhone this week I was surprised but pleased to see that WhatsApp now includes "WhatsApp Calling". As it says:
"Call your friends and family using WhatsApp for free, even if they're in another country. WhatsApp calls use your phone's Internet connection rather than your cellular plan's voice minutes. Data charges may apply.

How many ways can you spell "disruption"?
(Hint: w - h - a - t - s - a - p - p)

Sure, there have been a zillion mobile apps providing Over-The-Top (OTT) voice services, many of which I've written about here on this site.

But this is WhatsApp!

This is the application that just passed 800 million monthly active users! (Techmeme link) With projections to hit 1 billion monthly active users by the end of the year.

Oh, and it's owned by Facebook! :-)

Now, I personally don't use WhatsApp that much right now. The people who I want to message are primarily using iMessage, Facebook Messenger or Wire. (And every once in a great while I'll fire up Skype on my iPhone.)

But obviously there are 800 million people who do use WhatsApp each month... and they now have free calling! (If they are on Android, iOS or BlackBerry 10... and subject to a staggered rollout, i.e. people will get the actual ability to call over the next while.)

It will be fascinating to see how this plays out.

WhatsApp provides a messaging app with a very simple user experience (UX) that works seamlessly inside the iPhone. Now that same app can be used for calling. And most importantly, WhatsApp has the massive directory of users.

The legacy telcos are going to be saying good bye to even more of their diminishing calling revenue...

Interesting times ahead!

More on this topic:

Congrats to the Jitsi Team On Their Acquistion By Atlassian


Congratulations to Emil Ivov and the whole team behind Jitsi for their acquisition by Atlassian! As they say on the Jitsi news page:

The Jitsi Community just got a lot stronger! BlueJimp, founder of Jitsi, is now part of Atlasssian! The plan is to keep Jitsi at the cutting edge of innovation by keeping it open and in the hands of those who created it in the first place: the open source community.

The news is outlined in an article on TechCrunch and explained in more detail in a HipChat blog post.

To be clear, Atlassian is acquiring the company BlueJimp that employed the founders of Jitsi, but in the process they are also effectively getting the open source Jitsi project. It's great to read in their blog post, though, that they intend to continue to support and invest in the project.

I've been a big fan of Jitsi for quite some time as it was one of the earliest VoIP clients to support both IPv6 and DNSSEC. I wrote about this support both here and also over on the Deploy360 blog and recorded this video interview with Emil Ivov:

Previously I'd also written about Jitsi's support for DNSSEC as it was the first softphone to do so.

More recently I've been using Jitsi's WebRTC-based video bridge for some of the remote participation work we've been experimenting with inside the IETF.

It's all great work and I'm delighted that Emil and his team have found a home inside of Atlassian. I hope it works well for them all and I hope we see further evolution of Jitsi and other similar products.

Congrats to the whole team!

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Jim Courtney Discussing His "Experience Skype To The Max" Book on March 27 on VUC at Noon US EDT

Vuc534 skype to the maxWant to learn more about what's up with Skype right now? Tomorrow, March 27, 2015, at 12 noon US Eastern, my friend Jim Courtney is going to be discussing the new second edition of his "Experience Skype to the Max" on episode 534 of the VoIP Users Conference (VUC) podcast.

As noted on the VUC page, Jim will be talking about:

  • New features over the past three years and why they don’t have the “buzz” impact that new features used to have. Are we becoming calloused to anything new?
  • The challenge of innovating with a product that has built up a legacy and familiarity
  • The challenge of educating users about features beyond free voice and video calling (and it’s also a challenge for smartphones – to make users realize there is value in all those applications available beyond voice calls and SMS messages).
  • The feature set to consider when evaluating other alternatives
  • The directory issue
  • Skype vs Skype for Business
  • Asynchronous vs real time comms (migrating to IM backend has allowed more “persistence” with chat messaging, for instance)
  • Anytime communications Rooms

It should be a good session. I've known Jim for many years through his blogging about VoIP and he has a great amount of knowledge about Skype. Sadly, I'll be occupied with IETF 92 activities during the live broadcast so I will have to catch up with the recording of the session.

It's probably best to also join the IRC backchannel where links are shared, questions are answered and other comments occur. You also can visit the Google+ event page for the VUC #534 session today where there may be additional links and info.

If you won't be at your computer, you can also call in via:

  • sip:[email protected]
  • +1 (646) 475-2098

The session will of course be recorded so you can listen/watch later. Here is the YouTube live video stream:

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