A Raspberry Pi, Asterisk and Ekiga a Skype Alternative?

The previous post on the Raspberry Pi as a GSM gateway has made me think of what other uses such a setup could have. A bit of a thorn in my privacy and open source loving heart is Skype. Closed source and controlled by Microsoft is about as far away from privacy and open source as one could imagine. But it works and I use it quite often and especially with its video calling option I didn't see real alternatives. That is until now…

Perhaps the following setup should do the trick:

  • A Raspberry Pi hosted at home
  • Asterisk on the Pi, 25 Mbit/s down and 5 Mbit/s offers ample capacity for voice calls
  • Ekiga for SIP telephony between two PCs. According to the Ekiga page, HD voice and HD video streaming are supported.

So on paper this looks pretty cool as it would cover my application of making video calls between two PCs, one usually in my home network and the other somewhere on the Internet. With the SIP telephony server running in my own network and the voice and video stream running peer to peer it's about as private and open source as it gets. But how well does it work in practice? There are lots of unknowns beginning on the PCs and how well Ekiga runs on them down to the network layer and how Ekiga can handle the NATs in between. With a spare RasPi available I wonder how long I can resist giving it a try!? 🙂

A Raspberry Pi as a GSM Gateway

I've been running my ownCloud server on a Raspberry Pi for quite some time now and to say I am enthusiastic about it is rather an understatement. The Raspberry's versatility is incredible and I've recently come across another application that could come in quite handy in the future: Running Asterisk PBX on a RasPi and using it as a GSM Gateway.

Here's a post over at the Carrier-Connect blog that describes such a setup to forward calls over IP for a person's mobile number of country A to the person's mobile number of country B with the help of two Raspberry Pis and two 3G/GSM data sticks that are also circuit switched voice capable. And to make the Asterisk setup as painless as possible there's even ready to go Raspberry Debian (Raspbian) image and documentation available here. Amazing!

I’ve Seen A Foreign ownCloud

From what one reads on the web, OwnCloud seems to have become quite popular. While I have two small Owncloud servers of my own at home I had yet to see someone else use it, too. And to my surprise it happend faster than I thought.

When I recently passed by the desk of one of my co-workers I noticed the familiar ownCloud design in his web browser. It turned out that it was the ownCloud of a company that wanted to share a number of documents with him without using a public storage provider.

Very nice so now I know for a fact now I am not alone. While Dropbox or similar services would have spared the company the effort to set up their own server it looks like privacy and confidentiality were ranked higher than convenience.

How nice!

International Bandwidth Equalization

Here's a link to an interesting post over at Telegeography titled "International bandwidth demand is centralizing". The figure at the top of the post nicely visualizes the two key messages:

Not surprisingly lit (used) capacity of undersea cables continues to increased at a staggering pace, around 50% year over year. Between Europe and the US, for example, capacity of around 12 Tbit/s was added in the past 5 years. Terabits…

The second point of the figure is that unlike in previous years, bandwidth additions have been pretty much equal across the globe and are no longer focused just between Europe and the US. I would have thought differently with the majority of cloud and video streaming services being operated by US companies. But perhaps not so surprising at all with companies such as Akamai making sure content is not streamed across undersea cables but from a server as close to the user as possible.

ownCloud and Bookmarks

Remember Delicious? Once upon a time I used Delicious quite a lot to store bookmarks I didn't want to have in the bookmark menu of my web browser and which, in all likelihood, I would never need again anyway. But one never knows and there are pages which are not easily to be found with a search engine and every once in a while I was glad I could go back to my "bookmarks dump".

Then in 2011 Delicious as we knew it faded away and morphed into something different and I had to re-import the bookmarks into my web browser which was an adventure all by itself. This worked quite well for some time but for some reason the bookmark search algorithm in Firefox was really slow and I had to delete the better part of my bookmark pile. But now I'm back in the game again with the ownCloud bookmark application.

After all my posts on ownCloud in the last couple of months you must either have one of your own by now or be weary of my ramblings on it. But I can't help it, I just like it and it proves more and more useful every day for sharing documents as well as calendar and address book synchronization. With a little bookmarklet in the browser I can now save bookmarks again in the cloud with a single click and search through them when needed in ownClouds browser based GUI.

Just like in the good old Delicious days but with privacy added as the data is stored on my server at home. Perfect!

Beware of a Carrier Grade NAT (CGN) Near You

IPv4 addresses are slowly running out. As a consequence a number of ADSL and cable network providers have now started to give customers non-routable private IP addresses and perform Network Address Translation (NAT) at their border gateway to the rest of the Internet. As the NAT is performed on their turf they call it Carrier Grade NAT or CGN.

While being state of the art in wireless networks for many years now CGNs certainly have one advantage, they shield mobile devices from unsolicited packets from the Internet and hence keep power consumption down. Unfortunately there is a major disadvantage as well which is especially troublesome for fixed line connections at home: Your network is not reachable anymore for incoming connection requests.

Many people won't notice but as soon as you are running your own services such as an Owncloud server you are out of luck. Verizon, for example, is switchng to CGNs and private IP addresses and some German cable operators have started doing it as well. While Verizon at least offers a way to opt it seems that others are less flexible. Too bad when you signed a one year contract… I wouldn't be surprised if some will even start asking for extra money for a public IP address. Market economy, scarce resources, you get the idea…

IPv6 is obviously the solution but networks, devices and VPN gateways supporting it are still scarce. Therefore make sure before changing your home network provider that you will really get a public IP address!

The LTE Uplink Advantage – Give me 5, give me 10, give me 15 Mbit/s

The more I use my Owncloud server at home for exchanging files with others and keeping my calender and address book synchronized between various devices without relinquishing control (see here and here), the more I have come to like cloud services. I also use my Owncloud server at home while on the move via HSPA and LTE and when doing so, the major bottleneck is the uplink data rate.

For calendar and address book synchronization and also for downloading files from the cloud, an HSPA connection is fully sufficient. When uploading larger files to the cloud, however, HSPA becomes quite limiting. This is due to the limited uplink speeds of HSPA networks today, typically between 1 and 2 Mbit/s. How times and perceptions change… Not too long ago such speeds were considered amazingly fast. Not that this is an inherently wireless issue as ADSL uplinks are often even slower, most not even exceeding a megabit per second.

LTE is refreshingly different in this regard. When reception is good, I can easily achieve speeds way beyond the 5 Mbit/s my home VPN is limited due to the processing power of my VPN gateway. And for files exceeding just a few megabytes this makes a real difference.

So while for the most part I regard LTE as a capacity extension to server more simultaneous users rather than being there for offering higher download speeds, the uplink speed is the real differentiator for me!

Wetpaint – Bitten by Another Managed Cloud Service

Cloud services seem to be dying at an ever increasing rate these days. A year or two things started for me with Delicious abandoning its popular bookmark service, followed by the announcement of Google to discontinue their RSS reader at some point this year. And now Wetpaint has decided to block the Prepaid Wireless Internet Access Wiki that they hosted on their servers for many years without giving any reasons or warning. Ouch.

Over the years Wetpaint seems to have changed its focus several times and today the hosted Wikis seem to be little more than an unloved project on the side for them. Already over the last year I have noticed that the server the Prepaid Wireless Internet Wiki is hosted on has become slower and slower to the point of being of little use. That should have been a warning sign and an incentive to think about moving the content. But I didn't…

Now the Wiki is blocked and there is no way to export the pages. Support on the Wetpaint Central site for such issues also seems to be zero and all my inquiries have been left unanswered so far. And so once more the lesson is: Never trust a cloud service, your data could be gone in the blink of an eye without any warning.

Too bad, the Wiki has proven to be quite useful over the years.

Who Pays Whom?: User – DSL Provider – Transit – Video Portal

Here's a question I haven't got an answer for that you might be able to help me with. Who pays whom in the following scenario?:

  • A = User
  • B = DSL Access Provider
  • C = Transit Provider
  • D = Video Portal

Obviously the user (A) pays the DSL Access Provider (B) a monthly fee for the DSL line rental

The Video Portal (D) pays the Transit Provider (C) since it sends a lot of data into the network towards the user.

Based on the business model User (A) might pay the Video Portal (D) a fee or the Video Portal is cross-financed in another way, e.g. advertising.

And here's the question: What is the business relationship between the DSL access provider (B) and the Transit Provider (C)? The majority of data exchanged flows from Transit Provider (C) to the DSL access provider (B). Who pays whom at this interface?

Any insight and references are greatly appreciated!

What Doesn’t Get Done Without The Daily Commute

Spring has kept us waiting here in Germany for quite long this year. At some point in March I was so fed up with standing on icy cold train station platforms so I decided to take the car for a couple of days and rather endure the traffic jams. While that has certainly helped against the cold weather I noticed to my surprise after a week that my personal email inbox kept getting bigger and bigger and my blogging rhythm had significantly slowed down. I would have thought I'd implicitly reinvest the time I save taking the car into doing these tasks at  different time of the day. But no, that time just went somewhere else. So while commuting with the train usually takes longer than going to work by car this experience shows quite nicely that it is definitely not wasted time at all. Quite the contrary. In other words, working on these things while on the move is not limiting due to less space, more noisy environment, etc. but rather enabling!