Buffertime (milliseconds) contains the server's event notification sending frequency.
This is a minimum time - event notifications will not be sent any faster than this unless MaxSize is greater than 0, in which case the server will send an event notification sooner to obey the MaxSize parameter. A value of 0 for BufferTime means that the server should send event notifications as soon as it gets them. This parameter, along with the MaxSize parameter, is used to improve communications efficiency between client and server. This value is a recommendation from the client and the server is allowed to ignore the parameter.