Google
It tells me 5228 tcp and udp need to be open.
Repeat for whatsapp, which seems to be a bit more port number hungry.
"WhatsApp messenger uses these ports: 5223, 5228, 4244, 5242 and 5222 "
"he WhatsApp application sends non-SSL data over SSL port 443."
I think somebody may have changed port numbers when Whatsapp got bought.