Monthly Archives: November 2007

H323 SIP Gatekeeper on Linux – Updated

Recently we acquired a nice Tandberg Video Conferencing system, we normally stick with the Sony range as its menu interface is very easy to use, but we decided to give Tandberg a try. What a beast, great slick menu system, loads of options, built in MCU (Multipoint Conference Unit), 2 XLR mic inputs (Phantom Powered), PCMCIA Wireless card slot…. just great….. until I tried to dial a URL and got the strange message on screen “Gatekeeper not registered” ….. it was like listening to the “Girl from Ipanema” song on a scratched LP disk.

Some guys out there will laugh and say, “clearly you need a gatekeeper for H323“, well that’s not my experience with the Sony equipment. Anyway, I saw it as an opportunity to learn something new and dove into setting up a simple gatekeeper. After some looking around I found the GNU Gatekeeper and got an old IBM e-server PIII and installed a pure Debian Linux distro which works beatifully on this old machine (FYI – with Gnome). Well without further ado, here are the steps I took:

1 – Downloaded and installed Debian Linux (using the netinstall version 34mb for the boot cd)

2 – Installed GNUGK easily with apt-get install gnugk (installs by default into /var/run/gnugk)

3 – Created the gatekeeper.ini file based on the tutorial on gnugk website (better to save it into folder /etc)

my gatekeeper.ini content

# main configuration

[Gatekeeper::Main]
Fortytwo=42
Name=GNUGK #put here any name you want for your gk

[GkStatus::Auth]
rule=allow

[RoutingPolicy]
h323_ID=dns,internal
002=neighbor,internal
default=explicit,internal,enum,dns,internal,parent,neighbor

GKRouted=1
H245Routed=1

[RewriteCLI] # change this according to your network
in:192.168.1.0/24=any=18001111
in:192.168.2.0/24=any=18002222
in:any=any=0

[LogFile] # creates log files and rotate them – in this case daily @ 23:00
Rotate=Daily
RotateTime=23:00

4 – restart gnugk with the following command (which can later be added to the startup runlevel)

gnugk -ttt -c /etc/gatekeeper.ini (-ttt will output lots of text and is good for finding any faults, but not essential for the functioning of the gk)
All done and I dialed to URL successfuly using my tandberg system.

Extra info: GNUGK Manual | Debian startup | Tandberg

Download Camtasia Studio 3.1.3 for Free

I usually use Wink 2.0 to create free tutorials on my computer. However this week Techsmith, the makers of Camtasia Studio, are making Camtasia Studio 3.1.3 available for free download.

You can download the software at http://download.techsmith.com/camta…amtasiaf.exe

You will still need to register for a free registration key when you install the software, as I discovered when I first tried to install it, and you can register for that at http://www.techsmith.com/camtasia/pcpls.asp.They will e-mail you the registration key, so make sure to use a real e-mail address.

They are doing this promotion in hopes to up sell you to the $149 to upgrade to the newest version 5. The $149 is half the normal price, so it’s a bit of a bargain if you want the extra features in the newer version. That said, Camtasia Studio 3 is very feature rich for most of what people need.

From reading this forum post about the free Camtasia Studio 3 it sounds like it might work better than Wink, so we will see. I have had problems with sound skipping while recording tutorials using Wink, as they report on the forum, so Camtasia Studio 3 should provide me with better audio.

Temporarily Block Users from Logging onto Windows Terminal Server

Put Windows Terminal Server into “Maintenance” Mode

I find that quite often if I am having to diagnose a problem on our Windows 2003 Terminal Server my users continue to log on and try to work. If my maintenance requires rebooting the server, or running diagnostics on the server then this can cause problems for the logged in users.

You can temporarily block users from logging onto the terminal server that you are performing maintenance on quite easily:

  1. Log onto the Terminal Server Console, the actual computer, not through remote desktop
  2. Open up the Terminal Services Configuration program, which is located in the Administrative Tools folder
  3. Click on Connections
  4. Right click on each of the communications protocols you are using for your terminal server (we only use RDP-Tcp)
  5. On the right click navigation highlight “All Tasks” and click on “Disable Connection”

Now your users will not be able to log onto your Windows Terminal Server until you re-enable the RDP-Tcp protocol, or which ever other protocols you are running.

To enable the Windows Terminal Services protocols, like RDP-Tcp, just follow these steps:

  1. Log onto the Terminal Server Console, the actual computer, not through remote desktop as this is disabled right now
  2. Open up the Terminal Services Configuration program, which is located in the Administrative Tools folder
  3. Click on Connections
  4. Right click on each of the communications protocols you are using for your terminal server (we only use RDP-Tcp)
  5. On the right click navigation highlight “All Tasks” and click on “Enable Connection”

That’s it, now your users will be able to log onto your Windows Terminal Server again.

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Remote Access Computer – PC or MAC

Using Remote Desktop Connection to access a remote computer whilst away has been around for a bit, but what if you want to connect to a Mac from a PC or vice versa – or want to access your Windows/Mac machine from Linux?

I came across a bit of software recently that seems to seamlessly allow either a Mac or PC (be it Linux or Windows) to access the remote computer.

LogMeIn comes in a bewildering number of flavours, but the one that interested me (naturally!) was the free version. Although lacking some features that the paid for version has (remote printing etc) the free version seems be an excellent choice for general all-round use. Simple to install, I will let you know if I come across any problems, but so far so good.

The Mac version is a bit tricky to find, but a ‘preview’ version is available here:

https://secure.logmein.com/products/mac

The developers say:

Can I use a Mac OSX computer to control a LogMeIn computer?

You can use a Mac to access a computer via LogMeIn, as long as the Mac is running OSX.

If you are running 10.4 or higher, we have a plug-in that will allow you to control a PC or a Mac. You will be prompted to install this plug-in automatically when you first connect to the PC. There are some known issues when using Firefox initially, so please use the Safari browser when installing the plug-in.

Currently, support for older versions of OSX (10.3 and older) is limited to using LogMeIn in Java mode. In order to do this, the OSX machine being used to control the LogMeIn machine will need the latest version of the Java Runtime Environment (JRE). You will also need to
use the Mozilla Firefox browser.

More information available here:

https://secure.logmein.com/products/free/

Setup Windows Terminal Server to Disconnect Idle Sessions

Sometimes when I have logged onto our Windows 2003 Terminal Server there have been over a dozen idle sessions. Many of these sessions have only been idle for short periods of time, but often we have sessions that have been idle for many hours, and sometimes even days.

Today I decided to limit the amount of time that disconnected sessions can sit idle for. I figured that allowing a disconnected session to be idle for 1-day would be generous enough, but still save on the idle terminal server sessions.

There are two ways to set up Windows Terminal Server Session limits. One through the Terminal Server Group Policies, and the other way using Windows Terminal Services Configuration. Because I only run two Windows 2003 Terminal Servers I have decided to use the Windows Terminal Services Configuration to limit the idle session time.

Here are the steps that I followed on each Windows Terminal Server:

  1. Opened the Terminal Services Configuration from Administrative Tools
  2. Clicked on “Connections” on the left side bar
  3. Right clicked the “RDP-tcp” connection type
  4. Open up the “Session” tab and then above “End a disconnected session” I selected the “Override user settings” check box.
  5. Then in the drop down next to “End a disconnected session” I can then choose how long after session disconnect it ends the session. I chose “1 day” as my Terminal Server session disconnect time.
  6. Click on “OK” to save your settings and close the Properties box

That’s it. Now 1 day after someone disconnects from their terminal server session their session will be ended and it will no longer use up system resources.

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Should I Fix and Repair my Laptop or Replace It?

Recently my Compaq Presario v4000 completely died. On boot it would simply give me one long beep, followed by two short beeps. This appeared to be a video card problem.

Compaq Presario v4000 with keyboard removedIn a desktop computer this would be an easy, and relatively cheap repair. One of the challenges with laptops is that in most laptops the video card is integrated onto the system board, or motherboard, or main board, depending on what you want to call it. So to fix the video you need to replace the entire system board.

Again, replacing a system board in a desktop computer is easy, but with a laptop it’s a lot harder, and way more expensive to replace a system board in a laptop.

I priced out a new system board for my Compaq Presario v4000 and here in Australia it would cost nearly $700 for a new system board! I can almost purchase an entire new laptop for that price, with a one year warranty on it. The replacement system board would only come with a 90-day warranty.

I decided to check out e-bay to try to find a replacement system board, but when I looked the only one I could find was an untested board, with no warranty, over in Canada for $75.00 + shipping. That doesn’t help me much here in Australia and seems like a bit of a risk.

Bottom of the Compaq Presario v4000 with the case removedThe other problem is that the Compaq Presario v4000 laptop seems to have an inherent problem with frying the CPU and/or system board. I am definitely not the only person to experience this sort of problem with Compaq Presario laptops. This is already the second system board in this specific Compaq v4000 laptop, and with it being out of warranty I am very hesitant to replace it again, especially if it would happen again in 6-months time.

In the end I decided not to try to fix the laptop. With the history of the laptop, the inherent problems with the Compaq Presario design and the cost / risk involved with fixing it I decided that it just isn’t worth the heartache.

I will be selling off most of the working parts, everything except the system board, on eBay Australia. I have kept the 2.5″ hard drive and purchased an external USB2 case for it, so I will also be keeping that.

Now I’m needing to raise the money for a new laptop. I’m probably going to be looking at the Dell Vostro 1400 to replace my old Compaq. When I get it I am going to make sure to pick up the 3-year Complete Care warranty, which has served me extremely well with my old Dell Inspiron 2650, which my wife is still using four and half years down the track.

With desktop computers the extended warranty isn’t usually needed, but as the dead system board in my Compaq Presario v4000 has illustrated, an extended warranty on a laptop is definatly a good thing.

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