All JSON-LD teleconferences are open to the public. Anyone may join and participate in the discussion. All teleconferences are announced at least 24 hours in advance on the JSON-LD mailing list.
Make sure you have a good headset with a microphone as any background noise is distracting to others during the call. If there is excessive noise on your connection, you will be muted until you need to speak. Make sure you join the IRC channel as links and code examples are usually shared over the chat channel.
Minutes for meetings prior to the creation of the JSON-LD Working group may be found here.