If the KeepAliveTime is set on a WriterGroup, a value slightly higher than the configured value of the group in seconds should be set as MQTT Keep Alive ensuring that the connection is disconnected if the keep alive message was not sent by any writer in the specified time.

The implmentation choses packet and message size limits depending on the capabilities of the OS or or the capabilities of the device the application is running on. They can be made configurable through configuration model extensions or by other means.