Notification of Network Events

One of the most important responsibilities of a data transport service provider is that of providing indications to the client when certain network events have occurred. The list of defined network events consists of the following:

• FD_CONNECT - A connection to a remote host or to a multicast session has been completed
• FD_ACCEPT - A remote host is making a connection request
• FD_READ - Network data has arrived which is available to be read
• FD_WRITE - Space has become available in the service provider's buffers so that additional data may now be sent
• FD_OOB - Out of band data is available to be read
• FD_CLOSE - The remote host has closed down the connection
• FD_QOS - A change has occurred in negotiated QOS levels
• FD_GROUP_QOS - Reserved.
• FD_ROUTING_INTERFACE_CHANGE – A local interface that should be used to reach the destination specified in SIO_ROUTING_INTERFACE_CHANGE IOCLT has changed
• FD_ADDRESS_LIST_CHANGE – The list of local addresses to which application can bind has changed

The set of network events enumerated above is sometimes referred to as the FD_XXX events. Indication of the occurrence of one or more of such network events may be given in a number of ways depending on how the client requests for notification.