Tag Archives: VoIP

Dynamic DNS & Port Forwarding

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One thing that is necessary when dealing with IP videoconferencing is the whole network management thing. This means dealing with DNS, ports, and firewalls.

DNS remains a bit of a mystery, but in essence, the DNS system maps numerical IP addresses to domain names. So for example, my web site is located at 64.78.42.66. The way I know this is by running the NSLOOKUP command in Windows.

You can find your current public IP address by going to www.whatismyip.com

For help in setting up your router with port forwarding, go to http://portforward.com/

Laura Chappell produces fantastic tutorials on network troubleshooting. I should say “still”…because I’ve been reading her stuff since Novell was the networking operating system, and that is going back close to twenty years. The linked tutorial, from Novell Connection Magazine is entitled 10 Tasks Every Troubleshooter Should Conquer.

She references the SecTools site for tons of networking tools

Trixbox Installation Checklist

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Here is a short list of installation tasks for the Trixbox PBX.

  • Assign fixed IP address to WAN port
  • Place in DMZ (temporarily)
  • Get software updates
  • Configure a Polycom SIP phone
  • Configure Voicepulse SIP provider account
  • Make test calls
  • Configure router QOS setting
  • Insert Sangoma A200 card
  • Configure Zaptel card drivers
  • Configure Octasic echo cancellation (in software)
  • Configure 2nd Polycom phone
  • Configure Grandstream phone
  • Configure Remote Office phone
  • Place Trixbox behind the firewall.

Once the install is configured, then we’ll need to monitor the ongoing reliability of the SIP connections. This was one of the issues that I’ve had earlier; the Trixbox would loose the registration with the SIP phone provider, thus hanging up on long-distance calls. Unfortunately, I never was able to get it to fail-over to the landline, and there were no clear errors at the phone that said that anything was amiss. Not good for end-users.

Trixbox.Org is the community site for the free version of Trixbox, called Trixbox CE (community edition).

Trixbox.Com is the site for the commericial, hybrid-hosted versions. One of these is also available for free. The others are sold per seat on a monthly or a lifetime basis.

Most of my previous Trixbox posts are available under the Trixbox and/or VoIP labels. Doing a quick search I just noticed that one of my first posts was EXACTLY one year ago…November 29th 2006. Guess I should go back and take a look so I don’t repeat my mistakes of the previous year.

Trixbox Appliance: New Baby

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Just unwrapped the new baby here… a Trixbox appliance (the so-called “base” model for about $999) that comes without landline interface cards. In its base configuration it is suitable for those who want to implement a fully IP-based VoIP system. I’ll be adding hardware to this; an existing Sangoma A200 card which provides two landline connections. I’ll only be using one of the two connections to start. I couldn’t resist starting it up, and sorry, but contrary to all the assurances; the thing is noisy. Too noisy to have setting next to my desk. Damn.

The dual power-supply version that was demonstrated back in June sounded like a jet engine. Definitely that one is a unit for the server room, not deskside.

We had our first real snow that stuck today, about three inches. The Trixbox will be a great project on those cold winter days.

HUD – Heads-Up-Display

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Kerry Garrison at Trixbox conducted a webinar last Wednesday on HUD, the Heads-Up-Display… a computer interface to the TrixBox PBX. HUD gives you a display of all current calls, allows you to forward calls, and make calls to others on the PBX without having to dial your phone. The client version interfaces with OutLook, but the whole application is cross-platform; it will run on a Mac, PC, or Linux box. It includes an instant messaging system, which allows you to IM all the people who are on the system. Although they are currently using a proprietary IM protocol, an update will use the jabber protocol….which will allow you to include IM participants on AOL and other instant messaging systems.

One thing addressed in the webinar is a way to integrate your phone system with web applications, so you can use HUD with Salesforce, and SAP or other “customer relationship management” or CRM products. So, what might HUD be used for?

  • Call centers; inbound and outbound
  • Suicide and rape crisis lines
  • Counseling centers
  • Outbound solicitation (blood donors)
  • Clinic phone systems

Even if you never would consider using Trixbox, the webinar is useful to show the kind of functionality that is available in similar systems. The possibilities are mind-boggling.

There is an interactive demo.

The webinar is located here. It requires registration.

Suggested Routers for VoIP

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In addition to the new Trixbox training mentioned the other day, Fonality is now offering commercial versions of TrixBox…called Trixbox Pro. This is offered as a “hybrid hosted” model, in which you supply the server and other hardware, but the server is more or less permanently in contact and managed from their hosted server application.

As they are rolling this out, they seem to have upgraded the help support wiki, with some very specific information gleaned from their experience of deploying over 60,000 phones. For example, here are recommendations for routers suitable for use with VoIP.

They have also published a hardware compatibilty list, which lists certified, (fully supported) hardware and uncertified (supported by at a 25% cost premium) hardware. Of interest are several HP servers that are certified, and the Dell SC440 (tower), and 1950 (1-U rackmount). Aastra and Polycom phones are on the certified list, as are Sangoma interface cards.

On the suggested router list at the low end are the Linksys BEFSR81, D-Link DI724U and Fortinet Fortigate 50B.

They also have a “blacklist”…stuff that they don’t recommend for various reasons. These include problems with firmware (notorious with some low-end routers), and design incompatibilities. Sure enough, my BEFSX41 is on the blacklist.

Trixbox Training – More and Better!

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Trixbox has added some more in-depth training options. I took the FtOCC (Fonality Trixbox Open Communications Certification training in June, and it started to get interesting on a technical level.

Now the TB folks have two new courses that go deeper into the technology:

  • FtOCC Technician (trixbox CE, Pro and PBXtra)
    FtOCC Technician is a three-day technical certification course designed to train resellers and consultants to support their clients running trixbox CE, trixbox Pro, and PBXtra systems. Taught by Fonality technical support instructors, FtOCC Technician dives deep into platform and application installation, carrier setup and integration, network configuration, echo causes and remedies, and other common issues. A requirement for Authorized and Premium Resellers, this course should be taken by Linux technicians and engineers who regularly support client installations.
  • FtOCC Engineer (trixbox CE, Pro, and PBXtra) FtOCC Engineer is a new course designed to teach engineers how to do custom application development for trixbox CE, Pro and PBXtra. Write deep CRM integration, database dips, text-to-speech, internet look-ups and more by combining the Asterisk Gateway Interface (AGI) and Asterisk Manager Interface (AMI) with a CGI, SQL database, IVR, or all three. Want to hear a perl-based IVR in action? Call 310-861-4393 and hit option 2. Taught by Fonality’s lead engineers who created trixbox Pro and PBXtra, this course is for serious programmers with deep Linux knowledge.

The original FtoCC training course now appears to be renamed Trixbox Administrator course, and is the “entry-level” course of the series.

Even if you aren’t selling and installing Trixboxes, the courses are useful on a general level as you learn a great deal about Asterisk, VoIP, Linux, echo-cancellation, etc.

Microsoft Action Pack Update for July

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One reason why I like the Microsoft Action Pack is that it gently feeds you a trickle of the tsunami of new Microsoft products, betas, Community Technology Previews (CTPs), samples, trials, and templates. This months quarterly update is no different and includes a couple of interesting products:

  • The 64 bit version of Vista Business
  • Beta 3 of Windows Server 2008 Enterprise in both 32 bit and 64 bit versions.
  • System Center Essentials 2007
  • Office Live Communications Server 2005 Enterprise Edition
  • Windows Server 2003 R2 32 and 64 bit

I’ve been running Windows BackOffice 2003 on my server for what I think is at least two or three years, so I’m contemplating installing one of the straight Windows Servers as a replacement. BackOffice is fine if you want to run Microsoft Exchange, and you want to have some beefed up management tools, but I’ve never been convinced of its utility over the regular Windows Server product. Exchange is a whole trip in itself, (can you say backup and spam control?) and in small offices that would otherwise be the typical customer for BackOffice, I would normally recommend just going with mailboxes from your internet service provider.

Live Communications Server is the Microsoft VoIP back-end product…something I’m interested in looking at; but was unable to install on my Win 2003 BackOffice server.

The Action Pack is a quarterly shipment to Microsoft Partner subscribers, and is suited for small consultancies or businesses with ten or fewer desktops. You get the full office suite with all the goodies like Visio and MapPoint, as well as all the server operating systems. No development tools–that is for the Microsoft Developers Network Subscription, but so many of those are available as trials and free versions that you can get pretty far without spending a lot in that area.

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Ekiga, formerly known as Gnomemeeting, is a Linux based softphone/videophone. (A newer version is also available for Windows). They’ve thought of everything… STUN, H.323, SIP, a directory, NAT traversal, you name it.


I’m using version 2.03 that was in the stock installation of Ubuntu Feisty. After a couple hours of fiddling, (at least 30 minutes of which was finding out that my microphone was switched off…) I’ve been able to make test voice calls to what sounds like their Asterisk server. Looking around, it says they are up to about 2.09, and if you want it work full-screen, you have to compile from the source code.

Trixbox and VoIP Update

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I have done an extensive hoeing out of the VoIP Resource Guide, if you thought it was getting a bit long in the tooth, there are new items and I’ve deleted a lot of the old stuff. But, to cut the chase, here are some Stuff That Works:

The above are components that I’ve been using recently. Just today I ordered another Polycom phone, and a Sangoma A200 FXO card to replace my Digium X100p card. The difference between the Polycom phone and the Grandstream B100 phones in sound quality is noticable, and the general fit and finish of the Polycom phones is outstanding. Of course they cost twice of what the Grandstream phones had cost.

Other things highly thought of:
At the Boston Trixbox seminar, people spoke highly of Aastra phones, and Rhino interface cards. M0n0wall, the open source firewall was also recommended.

Unsolved Problems:
I was really happy with Gizmo for awhile, but have never been able to get it to register with my Trixbox server. I fiddled, but always given up.

And, still looking for a QoS solution for my home router, so that when I’m on the phone, and am casually surfing the web, it doesn’t destroy the conversation mid-word.

Trixbox Boston

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The cockpit. Laptop with the VMWare image of Trixbox installed. You can see the version 2.2 management screen. To the right, a Polycom 330 phone. These were part of the package that everyone took home. These are really nice phones, a real step up for those of us who have been using lower-end phones in our Trixbox experiments.


Andrew Gillis tries to debug problems with David Mandelstam’s Polycom phone. If David can “brick” a phone…is there any hope for end-users? ;-0

Andrew, Kerry and Stefanie Chao-Narayan handing out diplomas.


The object of our affection. A pre-production TrixBox. This one was the enterprise version, with dual power supplies. It runs cool as a cucumber, but belongs in a server room or wiring closet, not under your desk.