A connection is uniquely determined be the source and

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A connection is uniquely determined be the source and destination ports. At any one time, there can only be a single TCP connection between a unique pair of ports. A given port can support multiple connections, each with a different partner port. Data Transfer Although data are transferred in segments over a transport connection data transfer is viewed logically as consisting of a stream of octets. Each segment contains the sequence number of the first octet in the data field. Flow control is exercised using a credit allocation scheme in which the credit is a number of octets rather than a number of segments. Data are buffered by the transport entity on both transmission and reception. TCP exercises its own discretion as to when to construct a segment for transmission and when to release received data to the user. PUSH flag is used to forced the data. During data exchange, a segment arrives that is apparently not meat for the current connection, RST flag is set on an outgoing segment. Examples of this situation are delayed duplicate SYNs and an acknowledgment of data not yet sent. Connection Termination The normal means of terminating a connection is a graceful close. Each TCP user must issue a CLOSE primitive. The transport entity sets FIN bit on the last
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