[HTTP connection] [SMS conversation]
[CP] ...................... [CPA] <===== content request ====== [DC]
[CP] <== content-request == [CPA] ............................. [DC]
[CP] ------ Accepted -----> [CPA] ............................. [DC]
[CP] ====== content ======> [CPA] ............................. [DC]
[CP] <----- Accepted ------ [CPA] ............................. [DC] wrong request
[CP] ...................... [CPA] ========== content =========> [DC]
[CP] <== delivery report == [CPA] ............................. [DC]
[CP] ------ Accepted -----> [CPA] ............................. [DC]
Note: SMPP gateway messages (passed back to CPA after sending something to
subscriber) aren't shown here as more low-level, but that's how CPA gets the
message status for e.g. delivery reports.
Note 2: error messages supposed to be passed to subscriber must be
marked as free by means of paid="false" attribute!