Table 2 summarizes the time needed to complete a successful request or reply call. The difference between these two operations is that am_request_N() calls am_poll() after the message is sent while am_reply_N() does not. The time needed to complete am_poll() varies with the number and kind of messages received. The overhead of polling an empty network is 1.3 s. The additional overhead per one received message is about 1.8 s.
Table 2: Cost of calling am_request_N() and am_reply_N() functions.
(The column for am_request_N() assumes that no messages are
received as part of the am_poll which is performed inside am_request.)