VoIP4Linux

I am off to GUADEC

2007-07-16T15:54:32.391347-08:00

July 16, 2007

Tomorrow, I am off to GUADEC. It is in the UK for the first time — in Birmingham.

I will only attend for the 3 core days, but I expect to hear interesting things about the astonishingly rapid progress the Telepathy project has made, more about Maemo, and about GNOME infrastructure, especially the new continuous build service.

I hope Ekiga can make use of the build service.

Mail me if you would like to meet me.

David
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The fun of project collaboration?

2007-03-13T18:55:03.713040-08:00

March 13, 2007

3D virtual worlds may be a leisure time fad, but the Silicon Valley gurus at Qwaq think it can be serious business. I suspect they may be right.

Investors and sponsors have put a lot into the open source Croquet project project, and some of the project's founders are now commercialising it with a service that allows you to drag and drop the day-to-day tools and applications that you use in your office and lab, into a new and more natural context.

Imagine being able to stand next to your teammate from overseas, pore over and tweak your latest web application, have a real conversation, then hang a couple of sticky notes for your colleagues in another timezone to pick up later. No polluting flights, no worries about everyone having the latest version of the spec, and the fun of being able to explore what changed in the little world since you last visited.

Somehow, I think the virtual room with the walls covered in Gantt charts will still be a lonely one.

David

What is hot? WiFi, UMA and convergence

2006-12-03T17:06:55.270077-08:00

December 3, 2006

There seems to be some real excitement about WiFi VoIP products.

On Friday, the Washington Post pointed out that Vonage will have a radical new range for 2007.

Also, 2006 has been the year for proving out UMA, the system that allows mobile cellular services (including phone calls, mobile web and SMS) to use WiFi and the Internet to travel cheaply and with better coverage and data rates. Glenn Fleischmann's August podcast gives an overview, and in the last few days, T-Mobile's public trials in Seattle challenge the main US landline operators with unlimited calls from home on your mobile phone.

I hope there are plenty of opportunities for enthusiastic entrepreneurs (like me?) to help people get the gadgets they need, and then hook them up to innovative, interesting and fun services.

How much does it cost to call a physical phone with Ekiga?

2006-04-11T10:58:46.133205-08:00

April 11, 2006

Nic from Italy asks:

I'm using ekiga to call my parent for free, but i've seen that's also the possibility to call phisical phones... but I didn't find anywhere how much does it costs! Do you know the prices or a webpage about those prices? Thank you all.
...
So if I understand right, Ekiga does not offer its own pc-to-phone service. To do this, i have to purchase from an external SIP provider minutes and then use ekiga as sip device?

Right. But, the ekiga project has a partnership with SIP/H323 provider Diamondcard. Click on the PC-to-Phone command under the Ekiga Tools menu - you will see a dialogue with a link to apply that will open in your default browser. That web page shows you prices.

No, I haven't used Diamondcard myself, but other ekiga users have.

Other options are discussed here:
http://mail.gnome.org/archives/gnomemeeting-list/2006-April/msg00150.html http://mail.gnome.org/archives/gnomemeeting-list/2006-April/msg00155.html

And if you have trouble, read this

David
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Can I keep my passwords and permissions when I install a new Linux system?

2006-04-07T10:26:30.342077-08:00

April 7, 2006

Tim is planning to upgrade his Linux system from Fedora Core 2 (FC2) to CentOS. His /home directory and shared files are on a separate disc, so he plans to install the new system on his main disc, and then mount the second disc when it is all done.

How can I preserve the exact users and groups on the current system, so that system permissions, home directories, passwords, etc. match up when the new OS is installed?
Tim

Good question! I don't know much about the Red Hat installers, but in general it is unlikely that installers will touch your list of users (except for perhaps adding a few new ones for running services, but even that is unlikely here as FC2 is so similar to CentOS.)

Make sure you have backup copies, and try installing right over your existing installation. When it reboots after installing, the system should continue to use /etc/passwd /etc/shadow and /home just as before. If it doesn't - that is why you have a backup!

After the install, scour the system for files ending with .rpmnew and .rpmsave. Those are configuration files where the package authors made sure that their install script preserved a copy of your existing settings, while recommending new settings. Compare the old with the new, read any updated documentation, and make sure the settings now in force are what you really want.

If you prefer to have a completely clean CentOS install, then just copy or merge in /etc/passwd and /etc/shadow afterwards, and mount your old home directories. Again that will deal with home directory permissions, users, groups and passwords. Since you have an ssh listener, you will probably also want the old /etc/ssh/ but check for any changes to config syntax in newer versions.

David
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Skype, privacy and Zfone

2006-03-23T06:12:39.381251-08:00

March 23, 2006

This morning, Ric Harwood drew the attention of Bristol Underscore to this old article:
Beware eBay bearing Skype: ominous security omens

I took a look, and made my own contribution to Underscore (edited here):

I am not sure the article is up to the usual high standards of securityfocus, but very enlightening - and very topical, because Zfone was released last week.

SKYPE and VoIP: The article says that open standards VoIP (voice-over-internet-protocol) is not peer-to-peer and not encrypted, while Skype is. Not true. In fact both SIP and H.323 are peer-to-peer. Although some providers choose to route voice traffic over their own fibre, most don't. Further both SIP and H.323 have optional encryption, which some equipment supports. The problem is - for encryption to work, the caller and receiver must exchange trusted public keys (or shared secrets) 'out of band'. This is hard, and conventionally needs a troublesome Public Key Infrastructure, so hardly anyone bothers. Without the key exchange, VoIP, including Skype, is not private, even if it is encrypted, as it does not need any code-breaking skills to launch so-called 'spoofing' or 'man-in-the-middle' attacks. Without key exchange, encryption provides a totally bogus veneer of security. Skype might hand over your call logs to anyone who faxes (I don't know) but that is only one of your worries.

ZFONE : Last week, Phil Zimmermann (of PGP fame) published the sources of a beta project of his: Zfone - that will make make open standards VoIP conversations reasonably private without a public key infrastructure. Notice that his source is proprietary (not open source), but he is allowing the world to read it so that security experts can identify flaws in the encryption.

Andy Davies responded with an interesting link to slides from Black Hat Europe, that I bookmarked
Silver Needle in the Skype http://www.furl.net/item.jsp?id=7675311

David
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Open source code for Google Talk

2006-03-21T07:41:40.399609-08:00

March 21, 2006

Is gstreamer useful for VoIP and internet telephony?

This morning, I had a conversation with Robert McQueen of Collabora, an Open Source company from Cambridge, England. Robert and Rob Taylor have created the new Telepathy framework for building desktop voice and video telephony applications. Telepathy uses gstreamer to process the audio and video streams. By the way, it does Instant Messaging (IM) too.

They are using Telepathy to build a Google Talk client (see update below), and they once demonstrated how to build a SIP phone with an early version of Telepathy. If you have checked out the code, post a comment, or a link back to your site to let me know what you think about it.

Oh! if you like to hack on this stuff, apparently Collabora are hiring coders to supplement the busy crew of Telepathy and Farsight volunteers.

David

update Rob Taylor points out that their Google Talk client, Gabble, has no User Interface yet. Apparently the program works but it is really only a demonstration for developers to make calls with at the moment.
update 2 Robert McQueen tells me that hiring is done : they took on a new employee and some contractors.
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VoIP saving lives in New Orleans

2006-03-17T18:46:58.424728-08:00

March 17, 2006

I just read Jeff Pulver's announcement of the first VON medal of honor

Greg broke into an already looted Office Depot in New Orleans; removed the store's own, and only remaining, Cisco router (all the other equipment already having been looted); found a single live connection at a Hyatt hotel; downloaded a Vonage soft-client; and established communications with the outside world, including President Bush.

Ok - this is nothing to do with Linux - but all about freedom. I thought VoIP was just about the convenience of the calls coming to you wherever you are. But with a bit of imagination, the roaming and presence inherent in a good VoIP deployment can bring far more than just convenience.

Great work, Greg, and great award, Jeff.

David

p.s. I met eduardo on IRC last night and was able to point him to yesterday's blog can-ekiga-connect-to-my-voip. Eduardo had asked the original question about ekiga. I am pleased that he is now looking forward to testing ekiga with his ISP's voip service.

another Ekiga FAQ

2006-03-16T04:27:31.509456-08:00

March 16, 2006

Question asked on IRC late last night:

Mar 16 01:00:33 hi gals, hi dudes : )
Mar 16 01:00:34 you guys
Mar 16 01:00:51 at the office we're soon goin' to subscribe to a voip thingy through our isp
Mar 16 01:01:07 now i think we're mainly gonna use ip phones
Mar 16 01:01:12 but
Mar 16 01:01:23 one or two people might wanna be usin' a softphone
Mar 16 01:01:31 will ekiga work with it?
Mar 16 01:02:26 like, i wanna call an actual phone, but don't wanna use the diamodcards.us rates. instead, i wanna use the mclink rates, which is my isp, cause they're better
Mar 16 01:02:30 that doable? : )

I wasn't there to answer that in person, but the short answer is 'Yes' (unless you are going to subscribe to Skype.)

There are four open standards for making VoIP calls: the most established are SIP and H.323, and Ekiga does both of those - just type in the credentials from your provider. It takes 30 seconds. I don't use diamondcards: my provider uses SIP (or IAX), and it was that easy. My provider is gradwell.com: you can visit by my affiliate link or directly

The other open standards are IAX and Jingle. To use IAX you will need a 'gateway server' to connect a SIP client to an IAX service. An Asterisk server should do just fine for this, though I have yet to try it. Jingle is used by Google Talk. If and when Jingle becomes popular, there will be gateways available for that too.

In your case, for mclink, a quick check of their site shows

Per utilizzare il servizio MC-VoIP è necessario dotarsi di un dispositivo VoIP, hardware o software, compatibile con il protocollo SIP (Session Initiation Protocol).
https://voip.mclink.it/voip/apparati.aspx

so it should be easy.

David

update Damien Sandras pointed out that IAX and Jingle are not really standards, but open specifications. Jingle is just a new experiment, and only Google Talk, for now, seems to use it. IAX, on the other hand is fairly stable, and is used by dozens of inter-operating applications. Yet the IAX specification, though open, is controlled by Digium, not an independent standards body. David, March 18 2006

Ekiga videophone traverses firewalls easily

2006-03-15T23:16:55.724500-08:00

March 15, 2006

Until this week, many users of open source VoIP on Linux have had to struggle with configuring firewalls and crossing fingers to get the voice to travel in both directions.

That all changed on Sunday night with the release of Ekiga 2 http://www.ekiga.org

Not only is it a full-featured softphone and videophone; it supports the new open STUN standard that allows you to talk with zero configuration across most small business and home NAT firewalls.

Ekiga's full glory is designed for any system that can run GNOME (not just Linux.) If you are brave, and have a very recent GNOME, download the shiny new 2.0.1 sources and have a go at compiling them yourself (there are lots of dependencies.) Otherwise, volunteers are compiling packages for many platforms this week; and you should also expect to see Ekiga replacing Gnomemeeting in the next full GNOME release. (Gnomemeeting is an H.323 videophone that was completely rebuilt over the last year to create Ekiga 2)

David