The operation has timed out when using web services

I am using a .net console apllication(C#) which makes API calls to a web service. There is a large amount of data transfer.
The exception i am getting is "The operation has timed out".
I generated stub classes from WDL files and using them in client application.
Where can i set the timeout value.
Is it on the client application or on the web server. and what parameters are used to set the time out value.

thanks