why there is shortage of bandwidth for international traffic? If I may ask?
There are probably dozens of points where there could be congestion.
At your MSAG. Where multiple MSAG's point back to (the exchange in our country). Connections between Cities.
Connections out the country may be affected, but not necessarily all of them. Traffic to Asia might be fine but traffic to Europe might be congested.
What CarlT suggested try testing to the same servers, some inside your country and some outside.