Chapter 3: Transport Layer
     our goals: 
     understand              learn about 
       principles               Internet transport 
       behind                   layer protocols:
       transport layer           UDP: 
       services:                  connectionless 
        multiplexing,            transport
         demultiplexing          TCP: connection-
        reliable data            oriented reliable 
         transfer                 transport
        flow control            TCP congestion 
        congestion               control       Transport Layer3-2
         control
      REVIEW LAYERED 
      ARCHITECTURE
                                                Transport Layer3-3
                               source                 Encapsulatio
        message       M     applicatio                n
     segment      H              n
                  Ht  M
                   t
   datagram H                transport
               H H M
                n
                n  t
   frame H H H M             network
             l  n  t
                                link
                             physical                             link
                                                                physical
                                                                                    switch
                 destination                     Hn Ht M      network
             M     applicatio                 Hl Hn Ht M         link         H H M
                                                                               n   t
         H M            n                                     physical
          t
      Hn Ht M      transport
   H H H M          network                                                         router
    l   n  t
                       link
                    physical
                                                                               Introduction1-4
     Wireshark
     Wireshark is a piece of software 
       that can capture and record 
       network traffic “on the wire.”
     It also allows user to examine the 
       traffic in a nice GUI.
     We’ll use Wireshark to capture 
       network traffic, and write our own 
       analyzer.
     Our analyzer will peer into the 
       layers and examine in detail the 
       information in each captured 
       frame.                                   Transport Layer3-5
     Demonstration of Wireshark.
     Chapter 3 outline
     3.1 transport-layer s3er.5v cicoesnnection-
                                  oriented 
     3.2 multiplexing and demultiplexing
                                  transport: TCP
     3.3 connectionless transport: UDP
                                   segment 
     3.4 principles of reliable data 
        transfer                     structure
                                   reliable data 
                                     transfer
                                   flow control
                                   connection 
                                     management
                                                Transport Layer3-6
                               3.6 principles of 
                                  congestion 
                                  control
                               3.7 TCP congestion 
                                  control