To better understand why it works with some of you...and why it doesnt.
Download
http://www.nirsoft.net/utils/cports.html
it will show you what ports skype or any other program you are using uses to connect to the Internet.
ports are like channel or roads that are used by the program to communicate over the Internet.
This way we can better understand how some of you got connected...
Port 80 (http)
5060 (used by SIP n other phone softwares)
Theres a difference between using msn n yahoo voice chatting...and Skype n others....they use different protocols and ports. Thats why you probably can do voice talk with yahoo...but not with Skype.
Etisalat blocks these in 2 ways.
Software Application Signature: Ever software that uses the internet has a unique id to itself and itself only. Regardless of how it connects to the internet, its signature id is revealed. Thats probably why some versions work...n some others dont....Skyp probably changed they applications signatures name. You can easily find out the signature name of an application by using a network sniffer such as Ethereal.
Ports: common ports for voice over ip are 5060, and others. Sometimes, these ports are shared for other reasons. Take MSN for example. You cant block MSN using port 80 because port 80 is also used for internet browsing. But other ports are strictly used for their own purpose. Use google and type "5060" and see what pops up.
Protocols: more like ways in which computers communicate. They probably blocked SIP protocol...very impotant protocol needed for voice over ip to work. For skpye for example.
And dont forget to also state where you are connecting from? a freezone? Unsensored internet? Home use internet connection? and so on...
I got bored so i wrote this.