+------+
@end verbatim
+@item PING
+ Dummy packet only used for determining workability of the connection.
+
+@verbatim
++------+
+| PING |
++------+
+@end verbatim
+
@item INFO
Information about the file we have for transmission.
delete @file{.part} suffix from file's name and send @emph{DONE} packet.
@item When @emph{DONE} packet received, delete corresponding file.
+
@item When @emph{HALT} packet received, empty file sending queue.
@item Each second, node checks: are there any new @emph{tx} packets
appeared and queues corresponding @emph{INFO} packets.
-@item If no packets are sent and received during @ref{CfgOnlineDeadline,
-onlinedeadline} duration, then close the connection. There is no
-explicit indication that session is over.
+@item Each minute, if no packets were sent, node sends @emph{PING}
+packet.
+
+@item If no non-PING packets are sent and received during
+@ref{CfgOnlineDeadline, onlinedeadline} duration, then close the
+connection. There is no explicit indication that session is over.
+
+@item If no packets are received during two minutes (two PING timeouts),
+then close the connection.
@end enumerate