Chapter 9: Layer Of transport

Chapter 9: Layer Of transport

1. Is responsible for establishing a temporary communication session between two applications and to transmit data between them.

   • Some responsibilities
     • Tracking of individual conversations
     • Segmentation of data and rearming segments
     • Identification of Applications
   • Responsibilities of the transport layer
     • Conversation tracking individual
     • Segmentation of data and rearming segments
     • Identification of applications
   • Reliability of the transport layer
     • The control protocol of transmission (TCP)
       • TCP is considered a transport layer protocol reliable and complete, since it guarantees that all data reach the destination
         • In the TCP function there are three operations basic reliability
           • Numbering and tracking of data transmitted to a host specific from a specific application
           • Recognition of the data received
           • Retransmission of data without recognition after a determined time
         • features
           • Establishing a session
           • Reliable delivery
           • Delivery in the same order
           • Flow control
     • The datagram protocol of user (UDP)
       • UDP is a transport layer protocol more simple, although it does not provide reliability
         • provides the basic functions to deliver segments of data between the right applications, with very little overload and data review
       • features
         • the data is reconstructed in the order that they received
         • the lost segments do not send again
         • there is no session establishment
         • does not inform the issuer availability of resources
   • Number of ports
     • Port of origin
       • is generated dynamically by the emitting device to identify a conversation between two devices
     • port of destination
       • The client places a destination port number in the segment to inform the destination server of the service requested
   • Number of ports group
     • The Internet Assigned Numbers Authority (IANA) is the regulatory body responsible for assign the different addressing standards, including port numbers. exist different types of port numbers
       • Known ports (numbers from 0 to 1023)
       • Registered ports (numbers from 1024 to 49151)
       • Dynamic or private ports (numbers 49152 to 65535)