Transcript CCNA 1 Module 11 TCP/IP Transport and Application Layers

CCNA 1 Chapter 9
TCP/IP Transport and
Application Layers
By
Your Name
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Objectives
• TCP/IP transport layer
• TCP/IP application layer
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Routed Protocols Versus
Routing Protocols
Routing protocols determine the path that routed
protocols follow to their destinations.
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The Transport Layer Functions
Five basic services:
• Segmenting upper-layer application data
• Establishing end-to-end operations
• Sending segments from one end host to another
end host
• Ensuring data reliability
• Providing flow control
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Flow Control
• Avoids the problem of a host at one side of the
connection overflowing the buffers in the host at
the other side
• Ensures the integrity of the data
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Session Establishment
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Three-Way Handshake
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Windowing
• A method of controlling the amount of
information transferred end to end
• Information can be measured in terms of the
number of packets or the number of bytes
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Window Size
Larger window sizes
increase communication
efficiency.
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Acknowledgment
• Positive acknowledgment requires a recipient to
communicate with the source, sending back an
acknowledgment message when it receives
data.
• Sender keeps a record of each data packet that
it sends and expects an acknowledgment.
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Layer 4 Protocols
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TCP
•
•
•
•
Connection oriented
Reliable
Divides outgoing messages into segments
Reassembles messages at the destination
station
• Resends anything not received
• Reassembles messages from incoming
segments
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UDP
•
•
•
•
Connectionless
Unreliable
Transmits messages (called user datagrams)
Provides no software checking for message
delivery (unreliable)
• Does not reassemble incoming messages
• Uses no acknowledgments
• Provides no flow control
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TCP/IP Protocol Graph
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TCP Segment Format
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UDP Segment Format
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Port Numbers
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Application Layer
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TCP/IP Application Layer
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Responsibilities
• Identifying and establishing the availability of
intended communication partners
• Synchronizing cooperating applications
• Establishing agreement on procedures for error
recovery
• Controlling data integrity
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Application Layer Examples
•
•
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Domain Name System
File Transfer Protocol
Hypertext Transfer Protocol
Simple Mail Transport Protocol
Simple Network Management Protocol
Telnet
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Domain Name System
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FTP
• FTP is a reliable, connection-oriented service
that uses TCP to transfer files between systems
that support FTP.
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HTTP
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SMTP
• E-mail servers communicate with each other
using the Simple Mail Transport Protocol
(SMTP) to send and receive mail.
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SNMP
• The Simple Network
Management Protocol
(SNMP) is an application
layer protocol that
facilitates the exchange of
management information
between network devices.
• An SNMP managed
network consists of the
following:
– Network management
system (NMS)
– Managed device
– Agents
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Telnet
• Telnet client software provides the ability to log
in to a remote Internet host that is running a
Telnet server application and then to execute
commands from the command line.
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