[delta-chat] Algorithm of delivery of messages

Dear friends! Please explain the algorithm of delivery of messages: sometimes they go in one direction for a few seconds, and sometimes this time is from 5 to 10 minutes. Moreover, the rapid exchange of messages (question-answer) does not work, or there or back (quickly). I want to understand the algorithm in order to communicate the order of correspondence to their correspondents. -- Евгений Кабанов http://kabanov.tel