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Voice over IP, VoIP, is a trend for very near future. There are so many VoIP standards but the key component for developing a VoIP application is the voice codec. Standard voice codecs are not as good as acceptable comparing to telephone quality. Most of good and great codecs are patented. Fortunately,  gives high-quality GIPS from Global IP Sound to all of us free of charge. Though, if you concern about licensing, Libjingle 0.3.0  the high-quality GIPS or GIPS Voice Engine Lite which is totally free.

In the first part of this series, you see how ruby and python retrieve data from given URL and then parse the results using regular expression. In part two, the code is extended to query prices from  through .

1. Specify executable
   Ruby

   #!/usr/bin/ruby

   Python

   #!/usr/bin/python

2. Import modules
   Ruby

   require ’net/http’  

My friend provides a shared disk space among trusted friends. Everybody are allowed to upload files to and download files from this space. The problem is that free space run out so fast. I have to help him identify oldest files to remove. If you are on *nix-based operating system, you might know about "find", "du" and "awk". To simplify this tip, I will demonstrate how to use find effectively.

• You want to find files modified exactly 7 days ago.

  find . -ctime 7

• You want to find files modified 7 days ago or older.

  find . -ctime +7

According to an article in Linux Journal #144, Reuven M. Lerner demonstrated how to extend web services using other web services in Ruby. This article is very interesting and I love it so much even it is Ruby. I don’t have much experience in Ruby so I wonder how it could be implemented in Python. That’s the point drived me to post this blog. The original article shown 3 short programs which query prices by given ISBN from Skokie Public Library and . The first one is just very simple and short program for searching ISBN in Skokie.

I wrote several articles to deploy monitoring software in enterprise network such as Cacti and Nagios. These monitoring tools are based on so-called passive monitoring technique. In other words, they were activated to monitor and collect network metrics very fixed interval, says 5 minutes. There are another technique called active monitoring which is much more powerful. By actively monitoring enterprise network, you can track all bandwidth usage per IP for both local and remote ones. Sometimes, it was called sniffer. This technique usually used for short-period debugging network related issues, e.g., wrong network configuration, worm, DDoS, and etc. Anyway, it is possible to actively monitor enterprise network to track bandwidth usage or to find bottleneck which needs to run all time, day and night. ntop is my favorite for long-term network monitoring tool. It is free, feature-rich, and easy to install.

According to previous comment which pointed me to an article about Virtual Hosting in Pure-FTPd, I think that there are some misunderstanding about these ambiguous terminologies: Virtual IP, Virtual Host, Virtual Domain, and Virtual User. Before continue reading below paragraph, I just want to note that this post is based on my understanding. If you think it is incorrect, please let me know.

• Virtual IP - One machine has many IP address and many domain names. One IP address has an unique domain name. Actually, this is not the feature of application but it is a TCP/IP specfication. An service may bind only on one network interface, one IP address.