I think you have not enough info about how to run voip business..
it would be better you must hire a good tech guy who will fight from ur site…
and if voize qulity is not good enouhg in Arbia that is the other matter, might be u hv not properly install or u r making some small problem which is effecting to all ur system,.
ok give me idea which hw/software u r using .
Arshad