If the KeepAliveTime is set on a WriterGroup, a value slightly higher than the configured value of the group should be used as AMQP idle time-out of the AMQP connection ensuring that the connection is disconnected if the keep alive message was not sent by any writer. Otherwise, if no KeepAliveTime is specified, the implementation should set a reasonable default value.
When setting the maximum message sizes for the Link, the MaxNetworkMessageSize of the PubSubGroup shall be used. If this value is 0, the implementation chooses a reasonable maximum.
Other limits are up to the implementation and depend on the capabilities of the OS or on the capabilities of the device the Publisher or Subscriber is running on, and can be made configurable through configuration model extensions or by other means.