In general, most people don’t need to open any ports and can start streaming right away.
However, if you are having trouble and believe you need a port open, 1935 should be the key. This is the default port for RTMP (Real Time Messaging Protocol) services. Our service is setup to try to use ports 80 or 443 if 1935 isn’t open, which is why most should be fine.
For the more technical information about the ports, DaCast can use: TCP 1935, TCP 443 RTMP or TCP 443 80.