I remember when I was in Dubai sometimes Skype was u/s when the traffic on the internet was slow, with Etisalat its always slow, but sometimes unbearable.
As far as i understand Skype is a separate program and once installed only needs an active internet connection.
It cannot be blocked without blocking the rest of the internet.
Sure you cant get the home page , to top up your account but a friend or relative in a normal country can fix that..
If you need to download Skype type it into google there are other websites with the program that are not blocked as an example download.com
Any computer boffins care to explain how it may be blocked, and if there is a way around it....