port / protocol

Can the author of this application please tell me what port and protocol it uses to connect to google calendar information? I ask because my internet filter software will let me browse the internet just fine using a regular web browser but it won't let me use the google calendar agenda app. So I'd like to get details about it to the software filter company so I can get this fixed on their end.

Thanks.

This sounds a bit strange, but: TCP/IP port 80 and 443 (http, https)