OptionaladdOptionalconnectionExtra metadata to associate with the connection. This will be exposed on events like peer-connected, and can be used to add context to connections.
If this value is provided during renegotiation, it is merged key-wise with any existing metadata value for the connection (i.e. existing metadata values will not change, unless a new value for the same key is provided).
OptionalmirrorA raw SDP string that should be mirrored (best efforts) where possible to create an equivalent offer, including the same media with the same params.
When using mirrorSDP, for SDP that only defines video/audio media we will receive an offer with no data stream attached. This can be a problem for proxied connections, which need a data stream to hook up the external connection later. If addDataStream is set to true, a data stream will always be created even if not present in the mirrored SDP.
This option has no effect if mirrorSDP is not set.