ontains three phases: TCP connection setup, data transfer and connection close. TCP establishes new connections by carrying out the three-way hand shaking procedure [Ste94]. The connection requesting instance (a client) sends a SYN segment to the server. The server responds to the request by sending its own SYN segment and at the same time acknowledging the SYN of the client. To conclude the connection setup, the client has to acknowledge the SYN of the server. In total, the three-way handshake procedure involves three packets (each 40 bytes long) in one and a half RTT. 6 Dimensioning for Single ATM-Based lub In the procedure of connection release, each side sends a FIN segment indicating that it does not have any more data to transmit. The other side acknowledges this FIN segment by sending an ACK. This is a complete RTT. As TCP connections are full duplex, each side terminates the connection in one direction (this is called half-close). The data transaction time considers only the connection release time on the direction of data being received. Therefore, there are in total two complete RTTs and one additional uplink transmission for complete TCP connection setup and release procedure. Client Server Data Transfer (TCP slow start + congestion avoidance) Connection Connection Setup Close Figure 6.20: TCP Procedure Thus, adding the extra delay for setting up and releasing the TCP connection, the expected file transfer delay E{T(x)}* is expressed as with equation (6.27). It shall be noticed that the experienced round trip time during the connection setup and release phase is also subject to the link congestion. Thus, in equation (6.27) the varying RTT value RTTadjust is used as well for the round trip times. ET(x)}*=E|T(x)}+(2+UL_rtt _ratio)RTT adjust (6.27) 6.3.7.2 Extension for case with Single RAB and Applying CAC This section considers the scenarios when applying CAC to elastic traffic in the UTRAN transport network. The CAC function is often employed in order to guarantee a minimum throughput for each connecti