If using IIS 7.0 or above, the Request Filtering is enabled by default and the max allowed content length is set to 30 MB.

One must change this value if they want to allow file uploads of more than 30 MB.

Sample web.config entry:

<configuration>
    </system.webServer>
        <security>
            <requestFiltering>
                <requestLimits maxAllowedContentLength="314572800"/>
            </requestFiltering>
        </security>
    </system.webServer>
</configuration>

The above setting will allow 300 MB of data to be sent as a request. Hope this helps someone.