Hi venkatsan,
You have to add the connection timeout property to your connection string in the web.config file like below and and specify the value you wish. The timeout value set in the Connection Timeout property is a time expressed in seconds. If this property isn't set, the timeout value for the connection is the default value (15 seconds). Moreover, setting the timeout value to 0, you are specifying that your attempt to connect waits an infinite time.
connectionString="Server=.;DataBase=Test;UID=sa;PWD=password;Connection Timeout=0"
And add this to your web.config also.
<system.web>
<httpRuntime executionTimeout="180" />
</system.web>
Refer the below link for more details.
https://msdn.microsoft.com/en-us/library/e1f13641%28v=vs.85%29.aspx
