RSS
Twitter
Facebook
A connection-oriented transport
protocol needs a graceful method for shutting down an association.SCTP uses a
three-way handshake with one difference from the one used in TCP: A TCP end
point can engage the shutdown procedure while keeping the connection open and
receiving new data from the peer. SCTP does not support this “half closed”
state, which means that both
sides are prohibited from sending new data by their upper layer once a graceful
shutdown sequence is initiated Figure 5 depicts a typical graceful shutdown
sequence in SCTP. In this example, the application in host A wishes to shut down
and terminate the association with host Z. SCTP enters the SHUTDOWN_PENDING
state in which it will accept no data from the application but will still send
new data that is queued for transmission to host Z. After acknowledging all
queued data, host A sends a SHUTDOWN chunk and enters the SHUTDOWN_SENT state.
Upon receiving the SHUTDOWN
chunk, host Z notifies its upper layer, stops accepting new data from it, and
enters the SHUTDOWN_RECEIVED state. Z transmits any remaining data to A, which
follows with subsequent SHUTDOWN
chunks that inform Z of the data’s
arrival and reaffirm that the association is shutting down. Once it
acknowledges all queued data on host Z, host A sends a subsequent SHUTDOWN-ACK
chunk, followed by a SHUTDOWNCOMPLETE
chunk that completes the association shutdown
0 comments