Signal structure:

{
	"from":"",
	"to":"",
	"signal":"create",
	"content":"",
	"custom":{}
}

• “from” – This field is filled by Server. Server attach here unique ID of client who trigger action
• “to” – This field is filled by Client or Server. Here you can check your ID (in incomming messages) or point to whom signal should be propagated (in outcomming messages)
• “signal” – name of signal send or received from server
• “content” – for example conversation id, client SPDs etc.
• “custom” – This field is for client use only. This field will be pass in conversation to server and propagated to other client