TCP IP Illustrated

TCP IP Illustrated

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: he ACK, the state changes to ESTABLISHED. These state changes are summarized in Figure 18.17. Figure 18.17 Segments exchanged during simultaneous open. A simultaneous open requires the exchange of four segments, one more than the normal threeway handshake. Also notice that we don't call either end a client or a server, because both ends act as client and server. An Example It is possible, though hard, to generate a simultaneous open. The two ends must be started at about the same time, so that the SYNs cross each other. Having a long round-trip time between the two ends helps, to let the SYNs cross. To do this we'll execute one end on our host bsdi, file:///D|/Documents%20and%20Settings/bigini/Docu...homenet2run/tcpip/tcp-ip-illustrated/tcp_conn.htm (23 of 37) [12/09/2001 14.47.16] Chapter 18. TCP Connection Establishment and Termination and the other end on the host vangogh.cs.berkeley.edu. Since there is a dialup SLIP link between them, the round-trip time should be long enough (a few hundred milliseconds) to let the SYNs cross. One end (bsdi) assigns itself a local port of 8888 (the -b command-line option) and performs an active open to port 7777 on the other host: bsdi % sock -v -b8888 vangogh.cs.berkeley.edu 7777 connected on 140.252.13.35.8888 to 128.32.130.2.7777 TCP_MAXSEG = 512 we type this line hello, world this line was typed on other end and hi there this is output when FIN received connection closed by peer The other end is started at about the same time, assigns itself a local port of 7777, and performs an active open to port 8888: vangogh % sock -v -b7777 bsdi.tuc.noao.edu 8888 connected on 128.32.130.2.7777 to 140.252.13.35.8888 TCP_MAXSEG = 512 this is typed on the other end hello, world we type this line and hi there and then type our EOF character ^D We specify the -v flag to our sock program to verify the IP address and port numbers on each end of the connection. This flag also prints the MSS used by each end of the connection. We also type in one line on each end, which is sent to the other end...
View Full Document

This test prep was uploaded on 04/04/2014 for the course ECE EL5373 taught by Professor Guoyang during the Spring '12 term at NYU Poly.

Ask a homework question - tutors are online