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October 2014

Posts from September 2014

Talko Looks Very Cool, But Needed A Firewall Change To Work

Talko directoryThe big telecom story today certainly seems to the be launch of Ray Ozzie's new "Talko" application for iOS. Tons of attention in the tech media, and many of my friends on social media have been trying it out. There's a brilliant article posted on Medium about the "Brave New Phone Call" along with a great blog post from Ray Ozzie about how this new app will revolutionize the voice experience.

I think Talko has great potential to do so, particularly after using it.


... I had to change my firewall rules in order to make Talko work. :-(

And I don't know how long it will continue to work.

Perhaps worse than that... it wasn't clear initially that I had a firewall problem. Frequent testing partner Jim Courtney sent me a message and after installing the Talko app on my iPhone I tried to talk to him, but all I seemed to be able to do was send him a voice message or a text message.

Subsequently I tried connecting to Tim Panton and again could only send voice messages. It made for a very asynchronous "walkie-talkie" style of communication that clearly seemed to not be what was described in the article.

At that point my many years in VoIP kicked in and I realized the firewall at the edge of my network was probably blocking something. Sure enough, when I pulled up the live firewall log and filtered on my iPhone's IP address I could see blocked connections from my iPhone that were intended for an IP address in Amazon's EC2 cloud. These blocked connections happened when I tried to initiate a voice conversation within Talko.

I first tried to create a firewall rule that would allow specific ports through, just by guessing from the firewall logs what ports Talko might be using. However, they jumped around and what I ultimately had to do was create a rule allowing any connection from inside my network to the specific IPv4 address of what I assume is one of Talko's servers on Amazon EC2.

Once I did this, I was able to have a voice conversation with Tim perfectly fine. It was actually rather cool how it would record the conversation and let me easily go back, listen again, advance through it, etc.


... poking a hole in my firewall to a specific IP address is very definitely NOT the way to have a telecom application work.

And... Talko will only work on my network as long as that destination IP address doesn't change. If they add more servers or change their architecture, it's dead to me. At least... dead on my home WiFi network. Presumably it could still work on my mobile data network (at a cost to me).

Now, to be fair, I'm a bit more security-paranoid than the average home user and so I run a Linux-based firewall/server/gateway on the edge of my home network with a fairly restrictive set of firewall rules. The default policy is to deny outbound connections unless they fit into various rules. I've had to add rules allowing VoIP and IM protocols... and it's not uncommon for me to have to add new rules for applications like this. For instance, I had to do so for Tox when I was playing with it a few months back.

Odds are Talko will probably work fine for the vast majority of connections from WiFi networks with less paranoid firewall rules.

But... for an app like this to really challenge the existing telecom infrastructure, it needs to work from almost anywhere. This is why Skype usage is so ubiquitous - Skype "just works" and has its ways to work around firewalls. Within the SIP and WebRTC communities there are all the STUN / TURN / ICE servers and technologies that enable this kind of transit of a firewall. The technology is out there. And there will certainly be some enterprises and other businesses that set up firewalls at least as restrictive as mine is.

I realize today's news is the initial public launch and that this is early days for the app. I hope the Talko team can figure out a way to make the voice conversation work through firewalls. I really like what I see inside the app.

Meanwhile... I'm just hoping they don't change the IP address of the server with which my app is communicating!

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Three Years At The Internet Society

Internet sign london

Today marks three truly amazing years at the Internet Society.  It was September 19, 2011, when I visited the main office in Reston, Virginia, and began this wonderful journey.  I wrote back then about why I was taking this job to fight for the open Internet - and in truth the reasons haven't changed.

If anything, the situation has only gotten worse.  

There are now far more threats to what I've taken to calling the "Internet of Opportunity" ... the kind of Internet we have today where anyone can start any kind of service or publish any kind of information.  

Within the Internet Society (or "ISOC" as we are often called) we call this "permissionless innovation", not needing to ask permission of anyone to innovate.  If you have a new idea or a new service or product... you can just do it. You don't have to plead with a "gatekeeper" or pay someone in order to launch your service out onto the Internet.

But that could change.

Some of the legacy telecommunications companies who have lost out on revenue as everyone has moved away from phone calls would really like their revenue back.  Some of the entertainment and traditional media companies would like their revenue and control back, too.  And many governments would like to regain some of their control - and tax revenue.

Money and control.

As I wrote in that article three years ago, there is a great quote from the 1992 movie Sneakers:

“There’s a war out there, old friend. A world war. And it’s not about who’s got the most bullets. It’s about who controls the information. What we see and hear, how we work, what we think… it’s all about the information!”

That is definitely the case.  And that war is only gotten stronger... and it's going to get even more fierce in the years ahead.

I'm personally glad that there are a group of organization including the Internet Society that are dedicated to shining the light on the changes that are happening... and arguing for why we need to keep the current "open" nature of the Internet so that we and our children, and their children, can all benefit from the kinds of opportunities we've had to date with the Internet.

Last year I wrote a good bit about how pleased I was to be part of the Internet Society.  That hasn't changed!  My passion for the work that ISOC does around the world has only grown stronger in this past year as I have learned more of the amazing things happening around the world.  I continue to love my own work with the Internet Society Deploy360 Programme - I wake up each morning excited to write more and do more to help people learn how they can deploy new technologies to make the Internet work better, faster and be more secure.  I absolutely love what I do!

But I was reminded this week of how many other things are done by my colleagues all over the world.  I just game back from a 4-day all-staff retreat at a hotel in Virginia.  This was the first time an event like this had been held in over 3 years and we've added so many new staff that many of us had never met each other.  We spent the time talking about what our priorities should be... where did we see the organization going... how could we best help the Internet... what could we do......

It was an amazing time.  VERY intense... although certainly with some time for fun mixed in.   We came out with some great ideas and plans that I'm looking forward to making happen in the weeks and months ahead.

What struck me most is that the people are amazing.  It's truly an honor and privilege for me to serve with them and to do what we do.

The mission of the Internet Society is quite simple:

To promote the open development, evolution, and use of the Internet for the benefit of all people throughout the world.

It's that mission that brought me here... and that's the reason I continue to be as excited as I am about what I do. As I celebrate three years with the Internet Society, I'm very much looking forward to the next three years... and the next beyond that!

P.S. One great way you can help is to join the Internet Society to stay up-to-date on current issues affecting the Internet - membership is free for individuals. You can also subscribe to my infrequent email newsletter where I hit many of these topics.

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Watch Live TODAY (Sept 19) - CITI State of Telecom 2014

Citi logoWhat is the future of telecommunications and the Internet? As more entertainment moves to being over the Internet, what are the implications for the media and for the technology?

Today, September 19, 2014, there is an interesting set of presentations happening at the Columbia Club in New York City, organized by the Columbia (University) Institute for Tele-Information (CITI) called the "CITI State of Telecom 2014". Subtitled, "From the Internet of Science to The Internet of Next Generation Entertainment Implications for Content, Technology and Industry Consolidation", the session description states:

The goal of the early Internet was to connect research institutions. Yet today 71% of all Internet traffic consists of video, games, and music, and that number is growing. This transition raises issues for media content, technology, industry consolidation, business strategy, and regulatory policy. Media companies, academics, policy makers, and technologists must think ahead.

You can watch it all live at:

The sessions are being recorded, too, and are available at that address.

The session agenda and list of all the speakers is available on the CITI event page. The quick summary is:

  • 9:00am Welcome and Introduction of Topic
  • 9:15am Session 1- Technology and business drivers of the transformation of the Internet
  • 10:25am Session 2- Emerging business, marketing, and transaction models for Next Generation Video (NGV)
  • 11:35am Coffee Break
  • 11:50am Session 3- Public Interest Dimensions in Next-Generation Video and Networks
  • 12:50pm Lunch
  • 1:50pm Session 4 - Consolidation in the network platform industry: drivers and impacts
  • 3:00pm Coffee Break
  • 3:10pm Session 5 - New TV and (video) OTT issues for telecom and media policy
  • 4:20pm Session 6 - Defining the future: initiatives to lead the next generation of internet video
  • 5:30 Closing remarks and reception

The sessions began 3.5 hours ago at 9:00am US Eastern and will continue for another 5 hours. I've learned a good bit from a number of the sessions - and am listening right now to the discussion around the challenges of getting Internet infrastructure deployed in rural areas of the USA.

Great sessions to listen to!

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How Do We Define 'SIP' For Telecom In 2014?

Sip question"What is a minimum set of specifications that a vendor must implement to be able to say that it is SIP-compliant?"

A friend asked me that question and my response was:

It depends.

and even more unfortunately:

I don't know.

It turns out to be a challenging question to answer... and it led me to ask:

  • How do we define what "SIP" is for telecommunications in 2014?
  • How do we help vendors move their products/services to be based on SIP?
  • As we talk about "turning off the PSTN" and "moving all telecom to IP", how can we make it easier for companies to switch to using SIP?

The reality is that being "SIP-compliant" does turn out to depend upon where in the larger SIP interconnection ecosystem the vendor is located.

Is the vendor:

  1. a SIP client, in terms of a "hard" phone, a softphone, or other application that is seeking to connect to a SIP server?
  2. a SIP server seeking to connect to a SIP "service provider" to have connectivity out to the PSTN and other SIP networks?
  3. a SIP service provider seeking to interconnect with other SIP service providers and to the PSTN?
  4. a middlebox such as a firewall or session border controller (SBC) seeking to be in the middle of a SIP communication stream?
  5. an application that interacts with SIP systems in some way? (ex. call recording, IVR, networking monitoring)

To be "SIP-compliant" really means you need to figure out what amount of "SIP" you need to implement to play your part in the larger picture. Particularly when the SIP "architecture" we describe isn't the pretty little picture we use:

Sip architecture

but rather a much more complex reality:

Sip architecture reality

Unfortunately, the "Session Initiation Protocol" (SIP) is no longer just good old RFC 3261 and a few friends. RFC 3261 provided a radical new way to do telecommunications... it was "HTTP for voice"... it was simple, easy and pretty amazing. If you have a moment, go back and read RFC 3261. It's a remarkable document and set of ideas.

However, there were two factors that started to complicate "SIP":

  • the "Internet" community kept thinking of new and innovative ways that they could do more with SIP-based telecommunications; and
  • the traditional telecom companies/vendors kept wanting to bring across more and more legacy PSTN functionality into the world of SIP, typically without changing that PSTN functionality so that they wouldn't have to change their business models or processes.

This combination set SIP up to slowly become more and more of an accretion of various hacks and kludges designed to either enable SIP to unleash new possibilities and/or to take over key functionality from the PSTN.

But in doing so it became so much harder to define what "SIP" was.

Back around 2008/2009, Jonathan Rosenberg tried with his "Hitchiker's Guide to SIP" that was published as RFC 5411 in February 2009:

Now consider that this contained about 26 pages worth of documents to be referenced... and this was back in 2009! In the 5 years since, the "Realtime Applications and Infrastructure (RAI)" area of the IETF has been extremely busy and a similar document today would be be MUCH longer.

But does such a long list really help?

Going back to to my list of different roles within the SIP ecosystem, do we need more narrower lists for each role? A SIP client connecting to an IP-PBX may not need to implement all of the same specifications as a SIP service provider connecting to the PSTN.

What is the minimum set of SIP specifications for each role?

SIPconnect sipforumThe good news is that for the second role I mention, the SIP server to SIP service provider, the SIP Forum has done some outstanding work with their SIPconnect initiative. You can find more info at:

You can download the SIPconnect 1.1 technical specification and see the great amount of work they have done. The idea is that ultimately any "SIPconnect-compliant" IP-PBX or other SIP server can connect to any "SIPconnect-compliant" SIP service provider. It should "just work" with a minimum amount of testing. The goal is to allow the more rapid deployment of SIP-based IP-PBXs and making this part of the interconnection puzzle work that much better.

So if you are a vendor of a SIP server, whether you call it an IP-PBX, a call server, or whatever... or you are a SIP service provider seeking to connect to SIP servers at your customers - in either case you have SIPconnect that you can use to be "SIP-compliant".

But what about the other roles?

What if a vendor has multiple products?

What if a service provider or enterprise is just trying to get "SIP" products to work together? What should they specify beyond the vague statement that a product should support "SIP"?

Now, there are other organizations that have attempted to answer this question. The 3GPP has a list of SIP specifications and the GSMA seems to have similar documents. The ITU-T has many recommendations but since they rename everything it's hard to understand what really links back to SIP - and many of the ITU recommendations are only available to members and so you can't easily view them.

Which brings me back to these questions:

  • Do we need a new IETF document that aims to update RFC 5411 with a newer list and perhaps "profiles" of what would be needed for different roles?
  • Is this something the SIP Forum or some other organization should take on?
  • Has someone else already created a concise list/document/specification and I just haven't yet found it?

And perhaps the even larger question:

  • Do you believe this is an issue that we collectively should be working on as an industry to help make the deployment of SIP easier?

What do you think? How do we define SIP in 2014? What should we do? I'd love to hear your comments either in response to this post here on this blog or out on social media where this is posted. (Thanks!)

An audio commentary on this post is also available:

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Walk-Through: Skype 5.4 For iPhone Lets You Host Audio Conference Calls

Skype 5 4 for iosSkype released a new version 5.4 of it's iPhone app that includes an interesting ability to host "group audio calls". In a post on Skype's "Garage & Updates" blog today, Skype's Gary Wong writes that the goal of this release is "to make it easy for you to host a group audio call with just one tap." They did that... and I'll show that below in a series of images walking through the process.

A couple of caveats and thoughts from the testing:

  • As Gary Wong noted in his blog post this first release is limited to four people in a group audio call.
  • It seems from the testing described below that the "group audio call" is limited to Skype users. I couldn't find a way to add in a call to an external phone number.
  • It also seems to be limited to the iPhone and is not yet available on the iPad.
  • Image sharing isn't seamless between Skype for iPhone users and Skype desktop users.
  • The user interface was a bit troubling when switching between parts of the group call.

With that in mind, here are more details...

An Architecture Change For Audio Conferencing

What's interesting is that this capability is a change from the way that Skype has historically "hosted" audio conferences. With the existing Skype desktop clients, when you launch an audio conference call, your computer does all the mixing of the audio streams.

For this reason, if you want the best quality audio conference (or "group audio call"... I note that Skype is pointedly avoiding using the term "conference call") your smartest plan is usually to find the person with the fastest computer and fastest Internet connection. The combination of those two factors can make your audio call work the best.

Perhaps obviously, as powerful as they are, today's smartphones aren't going to have the CPU or bandwidth to do all the mixing of the audio streams and sending them back out to all participants.

So this new "group audio call" feature from Skype has to be using some audio mixing happening back in servers in Microsoft/Skype's "cloud" (also known as their "central data centers"). Your iPhone then becomes the control center for the group audio call and also sends your audio stream and receives back the mixed audio stream.

Walking Through Group Audio Calls

Naturally I had to try this out and enlisted the help of two long-time fellow testers - Jim Courtney and Phil Wolff.

Part of this new feature is that there is now a "phone" icon at the bottom of every chat window on your iPhone. A simple tap of that phone icon will initiate a group call with "everyone" in that chat. I didn't have Jim and Phil in a group chat smaller than the 4-person limit, so I started out with a regular voice call via Skype to Jim. I then tapped on the "add a person" icon in the lower right and added in Phil. As the call was connecting to Phil, here is what it looked like:

Skype 5 4 p2

After Phil accepted the call, I could tap on the "multiple person" (or "group") icon at the top and see a list of who was on the call:

Skype 5 4 p3

Tapping the "star" icon on the bottom would add this to my "Favorites" in the iPhone Skype client. Tapping the "..." button brought up a small set of options:

Skype 5 4 p4 0

Choosing to "rename group" let me give it a new name ("Testing Skype") which then appeared at the top of the window:

Skype 5 4 p4 1

Now, Jim and I were both using Skype on our iPhones while Phil was connected using Skype on his Mac. Neither Jim nor I could easily figure out how to start a text chat, but as part of the call Phil had a chat open up in his Mac Skype client. Once he typed in that, Jim and I both had a chat window on our iPhone:

Skype 5 4 p5

Jim and I could then enter in messages in our iPhone clients without any problems. I also had a Mac Skype client open and Jim had a Windows Skype client open and we could see the chat messages there, too, and could type messages in those clients - it all worked fine.

One interesting issue was the support of sharing files or photos across the clients. When Phil dropped a photo into the chat on his Mac desktop client, I was unable to see it in my iPhone:

Skype 5 4 p6

Tapping the "i" icon next to the message brought me to a page explaining that the iPhone client only used Skype's new "cloud-based" photo sharing service. Curious to explore this more, I tapped the camera icon and shared out an image I had on my iPhone. The result was visible to both Jim and I (and no, that's not me but rather a contractor working on our house):

Skype 5 4 p7

However, now Phil was not able to see the photo in his Mac desktop client (nor was I) but was instead directed to go to a URL in his browser to see the image:


Phil said on our call that in order to view that photo he had to login to his Skype account. After our 10 minutes or so of testing this, Phil dropped off and navigating back to the "call" screen I could see that he was no longer on the call:

Skype 5 4 p8

At this point I could have tapped on the green phone icon to bring Phil back in, but we were done.

When this was over, I did now have my new "Testing Skype" chat with Jim and Phil in it - and at the bottom was a phone icon. Jim tapped the phone icon on his iPhone and reconnected all three of us into a call.

Final Thoughts

If I used Skype on my iPhone a great amount, I could see how this feature would be quite useful for initiating group audio calls. I could create a "group" (effectively a "chat") with a group of people and add that to my "favorites". Then I could simply go into my "favorites" on my iPhone client and initiate the call. Obviously the initial four-person restriction limits the usefulness to only small teams/groups right now, but presumably Microsoft/Skype will raise that limit over time as this feature rolls out more.

The audio quality was fine. I didn't see a way to find out the technical details, but the audio sounded high quality, i.e. it was using Silk or another wideband codec to give rich audio.

I did find the navigation to be a bit cumbersome and not intuitive. Switching between the chat window, the "call status" window (showing the participants) and the regular call window was not as easy as I would have liked. It took some poking and tapping to figure out how to move around.

We did wonder why Skype was rolling out this particular feature right now. Phil wondered if there might be competitive pressures with Apple's announcements coming on Tuesday - for example, will we see group audio calls for Apple's Facetime? We'll have to tune in to see!

It also may purely be Skype seeking to reclaim some of the leadership on features for OTT voice apps given that so many other players have entered the market. Whatever the case... the feature is now out there and available for iPhone users.

If you'd like to try this out yourself, you should be able to download an update from the AppStore.

If you have already tried it, what do you think?

An audio commentary on this topic is also available on SoundCloud:

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