TCP IP Illustrated

140489 01405 svr4discard bsdi1032 ack 13 3 4 5 6 7 8

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: the discard server and type one line. We then disconnect the Ethernet cable and type a second line. While this second line is being retransmitted, we type a third line. We expect the next retransmission to contain both the second and third lines. bsdi % sock svr4 discard hello there first line gets sent OK then we disconnect the Ethernet cable file:///D|/Documents%20and%20Settings/bigini/Docu...homenet2run/tcpip/tcp-ip-illustrated/tcp_time.htm (26 of 29) [12/09/2001 14.47.27] Chapter 21. TCP Timeout and Retransmission line number 2 and 3 this line gets retransmitted type this line before second line sent OK then reconnect Ethernet cable Figure 21.13 shows the tcpdump output. (We have removed the connection establishment, the connection termination, and all the window advertisements.) 1 0.0 bsdi. 1032 > svr4.discard: P 1:13(12) ack 1 2 0.140489 ( 0.1405) svr4.discard > bsdi.1032: . ack 13 3 4 5 6 7 8 9 26.407696 (26.2672) 27.639390 ( 1.2317) 30.639453 ( 3.0001) 36.639653 ( 6.0002) 48.640131 (12.0005) 72.640768 (24.0006) 72.719091 ( 0.0783) Ethernet cable disconnected here bsdi.1032 > svr4.discard: 1 bsdi.1032 > svr4.discard: 1 bsdi.1032 > svr4.discard: 1 third line typed here bsdi.1032 > svr4.discard: 1 bsdi.1032 > svr4.discard: 1 bsdi.1032 > svr4.discard: 1 Ethernet cable reconnected here P 13:27(14) ack P 13:27(14) ack P 13:27(14) ack P 13:33(20) ack P 13:33(20) ack P 13:33(20) ack svr4.discard > bsdi.1032: . ack 33 Figure 21.13 Repacketization of data by TCP. Lines 1 and 2 show the first line ("hello there") being sent and its acknowledgment. We then disconnect the Ethernet cable and type "line number 2" (14 bytes, including the newline). These bytes are transmitted on line 3, and then retransmitted on lines 4 and 5. Before the retransmission on line 6 we type "and 3" (6 bytes, including the newline) and see this retransmission contain 20 bytes: both lines that we typed. When the acknowledgment arrives on line 9, it is for all 20 bytes. 21.12 Summary This chapter has provided a detailed look at TCP's timeout and retransmission strategy. Our file:///D|/Documents%20and%20...
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