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 quality of service levels
• FD_GROOUP_QOS - a change has occurred in negotiated quality of service levels for the socket group
• · 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 that one or more of these network events have occurred may be given in a number of ways depending on how the client requests for notification.