all calls are monitored, i.e. saved to disk
if after 60 seconds on the queue the call is unanswered, the call is routed to voicemail
there are two levels of agents: agents 302 and 303 will answer the queue (level 1); only if none of them is available the call is routed to agent 301 (level 2). If nobody is available, the queue keeps trying until timeout is reached.