S → C {type:"multi_user_info", users:[{name:…, name_dn:…, cid:…, talking:…, audio:…, webclient:…}]}
multi_user_info - list of users connected to a multiuser endpoint (voice gateway, conference call).
The IXNX voice bridge sends such a list when you connect to it, and every time the list contents change (people added/removed from list or start/end talking).
arguments: