Asterisk, and other worldly endeavours.

A blog by Leif Madsen

Starting work on Asterisk: TFoT 3rd edition

As many of you know, I’m a co-author of Asterisk: The Future of Telephony. While my girlfriend is away in Mexico for a week with the girls, I’m going to try and focus a bunch of attention on getting A:TFoT 3rd edition started (which is much overdue).

If you have any ideas for topics you would like covered in the new edition, or something that wasn’t covered as heavily as you wanted in the 1st and 2nd editions, feel free to let me know, and your ideas will be considered! I hope to get the installation chapter written today, and as things progress, we’ll get them posted up on the web (likely somewhere on for review by the community.

We’re going to try and write mostly in the open as we have things ready to go, so a more thorough community review can be done this time around rather than the closed review we’ve used in the past and the “get it when it’s done” approach.

More information to follow in the coming week(s)!


Written by Leif Madsen

2009/11/23 at 9:03 am

Posted in Asterisk

Tagged with , , ,

16 Responses

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  1. Asterisk on virtual machines would be an interesting topic.


    2009/11/23 at 1:10 pm

    • There isn’t really much to running Asterisk on a virtual machine outside of running it like normal. I’ve run several Asterisk systems on virtual machines, and I don’t do anything different just because of it. Just install dahdi_dummy just like you would if you didn’t have hardware, and be done with it.

      Leif Madsen

      2009/11/23 at 1:19 pm

      • That in and of itself might be worth mentioning. Personally I like the idea of mentioning VMs with Asterisk, although I agree that for the most part, there isn’t really anything that needs to be done differently.

        Jim Van Meggelen

        2009/11/24 at 3:55 am

      • My experience is very different from yours. Timing glitches causing dropped frames etc. is common when running inside a virtual machine is common and impossible to troubleshoot. The worst part is that you don’t know if it’s the virtual environment or something in the latest Asterisk which you just upgraded to that causes it and you start chasing ghosts after a while. I tend to stay away from it.

        Jonas B.

        2009/11/24 at 10:22 am

        • I’m honestly not too sure how much can really be done about that. You’ve virtualized the environment the timing is coming from a kernel that is virtualized, so unless you’re running something like Xen which is a little closer to host kernel, there may be very little that can be done about that.

          I’ve experienced that kind of thing as well, and typically it’s the virtual machines (or the host) doing too much “stuff” and eliminating contentions from the CPU seems to be the solution to that. However, I don’t run enough virtual machines in busy production environments to really be able to speak at length about such a subject. I think Jim is probably right though, in that it deserves at least an honorable mention.

          Leif Madsen

          2009/11/24 at 10:35 am

  2. I would like to have a whole section on Real Time Asterisk rewritten, expanded, drop postgres, expand ODBC, bring it up to date. Also, I would like to see at least some focus on external tools integration (receptionist, jabber, unified messaging) and video conferencing. Otherwise, the book is awesome! [d]


    2009/12/15 at 4:04 pm

  3. I would like to see more on Real-time and AEL. Although I am successfully runnin a hosted PBX solution which I myself programmed using Asterisk realtime architecture and AEL, but it was a lot of guess work programming it, and still there are things which I don’t know how to do, e.g. when a user changes his sip secret, unless I do a sip reload, asterisk doesn’t update it. prune realtime bla bla bla I have no idea how it works and seems like it doesn’t work for me. I never had luck with real-time in Asterisk 1.6. So a better detail on real-time is good to have in the next edition of this beautiful book.

    AEL now I know good enough, but there are many who don’t and they could be better at dial plan programming if they knew it.

    Zeeshan A Zakaria

    2010/04/30 at 10:27 am

  4. There’s a lack of documentation on asterisk clustering.
    As i’m working on deploying a voice message broadcasting service, i would like to have more background on clustering and load balancing in asterisk.

    Adolphe Cher-Aime

    2010/06/09 at 10:05 pm

    • This is probably one of the more requested items and we are definitely covering it. We’ll be delving into defining the differences between fault tolerance, clustering, load balancing, and “five-nines” and what that really means.

      We’ll discuss things like distributed device state, load balancing, failover, remote information lookup with DUNDi, and other interesting tools.

      Leif Madsen

      2010/06/10 at 6:34 am

  5. Although there is a lot on Internet about the installation of Asterisk. This part remain unclear.
    I would love to have more details on the needed package for the installation of Asterisk and add-on. (need of libeditline0?, DAHDI instead zaptel, libtonezone1, fxload, …)
    And there is not much about Debian package needed for the installation.
    There have been quite new developpements on asterisk and some documentation are a bit out of date.

    New exemples about extensions.ael instead of extensions.conf.

    More detailed explanations about the processing with calls and the use of [peer] [friend] [user]. These terms are subject to a lot of confusions in the community.

    The differences between authentication, secret, remotesecret, and md5secret as there is so much mix by the VoIP providers.
    i.e. the examples in the 2nd edition book for provider in Switzerland don’t work at all. For instance, only the “secret” and the “defaultuser” paramterers are required to login by the provider.
    No need at all for “authentication” nor “remotesecret” paramters.

    Best regards

    Douglas Magnenat

    2010/08/11 at 3:45 pm

  6. What is the status of TFoT with dahdi?


    2010/10/28 at 5:13 am

    • I’m not really sure I understand the question, but Asterisk: The Definitive Guide (which is the new name for Asterisk: The Future of Telephony 3rd edition) will cover DAHDI instead of Zaptel.

      Leif Madsen

      2010/10/29 at 12:04 pm

      • I should have asked “When will the next book be available.” Given the new title, I quickly found that it’s due for release in March, 2011. I’ll check it out on the review site. Thanks.


        2010/10/29 at 12:40 pm

  7. Hi Guys,

    If you can talk about:
    1-Asterisk high availability, Asterisk Fail over. what H/W can use that it.
    2-Asterisk Clusters
    3-Integrate Asterisk with Cisco Avaya Nortel …etc
    4-Asterisk Hardware recommended for T1,E1,FXO,FXS cards and recommended H/W servers.
    5-Integrate Asterisk with LDAP, Mysql,Oracle,….
    6-Asterisk monitor tools

    If you want me to help you for something , your are welcome


    Mohamed Radwan

    2011/01/04 at 3:37 am

    • Most of this is being covered actually. We’re only a few days away from our first draft of the book, so it’s too late to request any new content, but you’re welcome to see what we’ve done at


      Leif Madsen

      2011/01/04 at 8:22 am

  8. Just as an FYI/Update: The book is called Asterisk: The Definitive Guide (3rd Edition) and is available from O’Reilly at

    The book is entering Q2 which means we have one last chance to review a couple of minor things, and then it goes back to O’Reilly for page breaking, and then printing! We should see a print edition shipping in April 2011!

    Leif Madsen

    2011/03/25 at 6:26 am

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