All That I Know

I have been looking at VoIP (Voice over IP) for more than a year now. First came the open-sourcing of the Asterisk VoIP server (which uses the SIP protocol) then a boom started that has now taken over the world. Mobile handsets that use Wifi to connect to a SIP server, PDAs connecting to SIP servers, Mobile phones with WiFi (or Edge technology in the USA) and of course softphones on regular Windows/Mac/Linux PCs.

What does all this mean to the layman?? Cheaper international phone calls over an internet connection. A lot of us have good broadband internet connections at home and/or at the office. Using SIP devices/software, people can call you or you can call them at a very small price or in some cases for free. SIP gives you a local telephone number in the USA or UK which your clients/family can use to call you up. To them it will seem as if you are sitting in that country but you could be anywhere in the world, but of course near a broadband internet connection.

Its good for business, making the client feel that you are available locally.

What does all this require?? You need to get a SIP account on a server running in the country where you want to have a local number. Your SIP device/software will connect to that server over the internet. When your client/family dials the local number, they are actually dialing to the server in their local country. The server connects the call to your SIP device/software.

You will get charged for both incoming and outgoing calls in this scenerio to your country of choice but the rates are much much lower than the regular telephone rates. The same technology is being used by some mobile companies here in Pakistan at the moment.

A good Windows based program that can be used as a softphone is XTen. It is available as a free download on a lot of freeware websites although not on the company’s website anymore. Just search for XTen SIP phone

This is a link on the CNet website with info about different VoIP servcies being offered.

I came across the best thing for Java developers while surfing the net last week. A Live CD with Java development tools on it, Pollix. Just boot your computer using this CD and you have J2SDK 1.4.2 + Eclipse + Netbeans + BlueJ + a whole lot of other dev tools with a complete Linux GUI OS.

Plus it already has Java servers like Tomcat and JBoss installed and ready to run as well. No more installation nightmares for newbees who just want to learn.

Who would want to use this. Well if you are a student and:

• you want to have the best Java dev tools all on one CD
• you need to show off your Java work in a presentation using someone else’s PC
• your netwrok admin has allowed people to boot PCs from a CD, you can have your whole development environment on a CD and can start working using any PC; you will not care about what is preinstalled on the PC itself.

This is also a great tool for Java teachers to recommend to their students. I have come across a lot of Java newbies who have trouble even setting up environment variables. I think this is a very good resource for teachers and students alike.

I have seen very often that in universities and schools the sysadmin installs Windows on all machines and students do not get a chance to see Linux at all. I think Live CDs is about to change all that. Its all about spreading the word.

Linux Live CDs have been around for a while now, still I meet so many people who have never heard of them. I just met a friend who has been working on cross-platform C/C++ development for over a year now and is the Linux guru at his office but he had never heard of them.

In short, a Live CD is a bootable CD that brings up a full working operating system without installing anything on the PC’s hard drive. A good list of Live CDs is given here. For me it started with Knoppix which is full Linux OS with the KDE GUI desktop, OpenOffice, plus loads of software all running directly from the CD.

Knoppix is the parent of a lot of other Live CDs, so on a lot of LiveCD websites you will find the words “Knoppix spin-off”. You see what Knoppix achieved over other Live CD distros was its awesome ability to detect hardware automatically without bothering its user. It works great with even laptops. It also has 3GB worth of software compressed into one CD. If you are new to LiveCDs, please start with Knoppix.

So one might ask, why a LiveCD? I have seen different answers to this question on the net. I actually like the idea of carrying around my whole operating system with me on a CD and a USB disk to save my work. I am also a sysadmin. I know how often PCs go down. Norton Ghost has saved my life millions of times, where the same OS image file could be installed on various similar systems without any problems; configure once, install everywhere. With Live CDs I can configure once, run anywhere … without installation.

My intranet PDC server went down last week, filesystem got corrupt. I had my user/group/password, Samba, cups scripts all backed up. I just put in a live STUX Linux CD, booted into the OS, kept the scripts and files in their relative places and viola .. the server was back up again in 10 minutes. A reinstallation would have taken hours.

I plan to post more of my findings in LiveCDs as time goes on. So keep coming back for more …