Not all countries are as open minded towards free information flow and VOIP. United Arab Emirates (UAE) is an example of this. Some Internet service providers (ISP) are not crazy about the thought of Skype eating into the bandwidth and thus the protocol has been blocked.
The best and easiest way to get around being blocked from using Skype is to connect to a Virtual Private Network (VPN). What this does is route your entire data traffic trough a server located abroad. This will mask the traffic from your ISP and you can now use Skype without a problem.
A VPN account is not free but it is a must to have and it is very affordable. The best provider on the market is by far Hide My Ass. They are fast, cheap and reliable and have great customer reviews. I suggest the 6 or 12 months package.
As a bonus you will now be able to get cheaper call rates as well – read more in this article: How to get cheaper call rates on Skype