Tag Archives: free

Hello 2012!! The most >Geek< fun I've had in a while

ok ok, so this is really not at all keeping up to trying to post regularly. Got too busy, had a baby, etc.. excuses.

Now, I have a great reason to post!! I just finished a little pet project, tiny one.. but I’m quite excited about it as it’s something I’ve tried to do over 10 years ago, but the products were bad. Now, with newer hardware and software it’s a reality!

I had just succeeded to build my home SIP infrastructure. With a SIP client on my iPhone, I can connect to my personal PBX server, and make calls to regular phones via a SIP to PSTN router.

You are lost? I just built my own VOIP system, which I can make data calls over the air, from my iPhone, connect to my home based VOIP system, and call to a land line. What’s so big deal about that? Here in Singapore, the digital land lines are completely toll free! All outgoing LOCAL calls are free. With 3G and 10GB of quota a month, I can make a lot of phone calls this way!

I will share how I did it… and boy, it’s not easy. This setup is not for the faint hearted to even attempt to consider. Leave it to the real IT geeks *cough*

Here’s a glimpse on what you’ll need.

  1. Home broadband connection which has preferably unlimited usage (as we get here in Singapore)
    +the broadband connection must always be up (otherwise you cannot connect from outside of your home)
  2. Home wifi  network, if you want to make calls via your SIP client in the smartphone
  3. A Linksys SPA 3102 (retailing for about S$100 in Singapore) – this is a VOIP Router
  4. Asterisk – a free PBX Server – run this on an old PC, or a small atom machine, or a virtual machine
    (I run mine as a VMware Virtual Machine)
  5. A SIP client for your PC and/or smartphone
    PC – A good and free SIP client called X-Lite (http://www.counterpath.com/x-lite.html)
    iOS – many choices available, free and paid I use the free client from 3CX (http://www.3cx.com/VOIP/voip-phone.html)

Generally, each item is easy to get up and running, but to get them working together was not easy, especially when you don’t understand half the terms involved. This is one of the craziest situations where I was looking at pages of configuration items and they are mostly abbreviated.

In addition, there are few up to date guides on the net which tells you what to do. I found lots of guides for Asterisk, some very good, but are for older versions. I’m using version 1.8, and there are lots that are now redundant. After all I’ve done to get things to work, I must say it’s actually not a lot of settings we need to make.

Credits will be given when due. I will link to the sites which I found the most useful information.


how to make your Windows PC run faster?

I don’t know anyone who has a Windows computer that doesn’t come to a crawl after using it for about a year. The computer takes 5-10 mins, and in worse cases 20mins to boot up to a usable state.

This happens for several reasons, and one of the biggest reason is due to file fragmentation. The performance hit gets worse if your paging file (swap file) is fragmented as well.

Since nearly 2 years ago, I found a nice, free defragmentation utility on the web. Back then, it was known as JKDefrag. The idea was good and it worked by calling native Windows APIs. This means that the programmer leveraged a lot on Microsoft’s native functions to do the work. His utility just provided the brain and coordinate the whole activity.

This is a good design that the utility will not do anything out of Microsoft’s comfort zone. Meaning, all moving of the bits and pieces of the file is executed as safe as it gets. JKDefrag did not have to re-invent anything.

Now, a newer version has been released and I’ve used it. The utility has been renamed as MyDefrag (mydefrag.com) and it has a new feature. This introduces a new dimension to what JKDefrag did. MyDefrag will now optimize the files, in addition to just defragmentation.

The new optimization idea is great! It basically re-orders the files on the harddisk into zones, and depending on the type of the file, the frequency of access of the file, the files are organized into each zone. I will not go into the specifics here, so if you like to understand in greater details what is done, you may read up from the website.

I’ve installed and optimized on my desktop and 2 netbooks. The end result is phenomenal! I can actually feel that the boot up time of these computers are shorter, and general usage experience of the computers have improved.

For anyone who wants to squeeze more out of their computers, I would recommend trying this utility out.

This utility is free, and you have the freedom to make a donation to the author of the utility if you wish to. I’m in no way affiliated to this author, and I’m writing this just to share with you out there this great utility I’ve discovered.

So, if you do try out the utility, what you need to do after installation is to run “slow optimize” the very first time you use it. That basically does the initial job to re-order the entire harddisk. Be warned though, this can take a very very long time… on one of my netbooks, it took 2 days, and the other took only 3 hours. So it depends how much work needs to be done.

So, go forth and unleash some renewed performance to your computer 🙂

free way to manage IP addresses

if you’ve ever setup a network and handled IP address allocation, more often than not, you may try to remember the network addressing in your head.

C’mon, how many people out there really document what you do. Techies are well known to not document what we do. Just about very often, we’ll end up forgetting what we have done before. When ever we have to revisit the environment, we’ll need to dig deep into our memory, hoping we can recall our work.

Face it, even I have learnt the lesson of not documenting. Age is catching up and memory is not as good as it used to be. Now, the very least I’ll document the important stuffs.

So, how’s this related to IP address management? I see it simply as documentation of IP address usage. If you do document your IP addresses, I’d guess you’ll probably be using an excel spreadsheet. Heck, a lot of people I know uses excel spreadsheets to track IP address allocations.

Such a document is critical to keep up to date, and you’ll need good team discipline to keep the information current. All you need is just one, yes one, slack in the updates and hell can potentially break loose.

So, here I have stumbled upon a nice tool released by Solarwinds. My network engineer once told me that Solarwind products are very powerful and useful to manage large networks. I never had the chance to experience it, but I’ve played a little with this niftly little free tool they have, the “IP Address Tracker”.

This free version runs standalone, and capable of scanning the given subnet for all IPs which are online at the time. If SNMP is enabled, it will also tryto automatically pick up some details regarding each device. You can also flag each IP manually to categorize them, in addtion you can certainly put down little comments for every address. It will also keep track on the current latency of the IP, the last known date and time it was reacheable.

The user interface is pretty straighforward, and I like it. I use it personally to help me document the few home networks I’m helping to up-keep for my family.

Now, it gets even better, this tool has a paid version which can integrate into the Solarwinds suite of tools. I haven’t seen how it works, but some features I’ve read include running the app as a service, so it can do a realtime tracking of used IP addresses. In addition, it will provide a web interface, meaning a team of network engineers can potentially use it at the same time. That’s my favorite bit, real-time automated documentation and tracking of IP addresses being used.

This tool can certainly save time and effort for network engineers.

With all these said, this tool is only for those networks which allows (I assume) ICMP pings. Otherwise, excel will be your best friend.