For ip to ip dialing you have to do diffrent things for h.323 and sip (two diffrent protocols). You only need to use one on the two enpoints (same protocol on both).
for h.323 set CallSetupMode to direct and under networkservices if not enabled turn on h323 - this should enable you to make and recive h.323 calls
Sip - set SiPListenPort to on - this will enable the endpoint to recive calls. The SIP network service is default on.
note that its not recommende to setup endpoints on public IP adresses. The SIP setting above will enable bots to make calls to the endpoint ( think a prank call every 5 minutes).
Hello, understand that I want to call from outside with a public IP address, what to do from my router? Port forwading? Which ports? And how?
Have a look a this thread about the SX20 (the SX80 has the same requirements): SX20 as standalone?