I have developed a java application that communicates with another instance of the same application on

another phone. The communication is done via sms, I am using port number 50010. The communication works

ok between two persons in Canada. But it fails with a person in French and another in Canada.
When a message is sent from France to Canada, the phone in Canada just gets three '?' characters.

I am just using WMA 2.0 to send the messages.
What could be the problem? Should I use other port number?

Thanks in advance.