What are required parameters for an ICE candidate?

Question

If I call toString() from a org.ice4j.ice.LocalCandidate object then I receive an output like:

candidate:1 1 udp 2130706431 192.168.233.1 10000 typ host

The candidate which I receive form a browser look different:

2791736470 1 udp 2122063615 192.168.233.1 59763 typ host generation 0 ufrag 8pZ1 network-id 1

We see additional values for generation, ufrag and network-id. Must I set this values or is this only a nice to have? If I must set it, where can I find the values for it?

Answer 1

generation, ufrag and network-id are non-standard extensions used by Google's libwebrtc (see RFC 5245 for the standard ones which may be followed by additional key-value pairs) which is used by Chrome and Safari. They can be ignored, other browsers like Firefox don't emit them either.