ccna day 1
DESCRIPTION
CCNA, CiscoTRANSCRIPT
© 2000, Cisco Systems, Inc. 2-1
Chapter 2
Internetworking Concepts Overview
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—2-2
Objectives
On completion of this chapter, you will be able to perform the following tasks:• Describe how data traffic is exchanged
between source and destination devices• Identify the roles and functions of a hub,
switch, and router, and where they best fit in the network• Select the appropriate Cisco equipment for a
given set of network requirements
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—2-3
OSI Model Overview
Application (Upper) Layers
Session
Presentation
Application
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—2-4
OSI Model Overview
Data Flow Layers
Transport Layer
Data Link
Network Layer
Physical
Application (Upper) Layers
Session
Presentation
Application
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—2-5
Role of Application Layers
TelnetFTP
User Interface
EXAMPLES
Application
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—2-6
TelnetFTP
ASCIIEBCDICJPEG
User Interface
•How data is presented•Special processing such as encryption
EXAMPLES
Presentation
Application
Role of Application Layers
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—2-7
TelnetFTP
ASCIIEBCDICJPEG
Keeping different applications’ data separate
User Interface
•How data is presented•Special processing such as encryption
Operating System/Application Access Scheduling
EXAMPLES
Session
Presentation
Application
Role of Application Layers
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—2-8
Keeping different applications’ data separate
User Interface
•How data is presented•Special processing such as encryption
TelnetFTP
ASCIIEBCDICJPEG
Operating System/Application Access Scheduling
Transport Layer
Data Link
Network Layer
Physical
EXAMPLES
Session
Presentation
Application
Role of Application Layers
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—2-9
Role of Data Flow Layers
EIA/TIA-232V.35
EXAMPLES
Physical • Move bits between devices• Specifies voltage, wire speed and
pin-out cables
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—2-10
802.3 / 802.2HDLC
EIA/TIA-232V.35
EXAMPLES
Role of Data Flow Layers
Data Link
Physical
• Combines bits into bytes and bytes into frames
• Access to media using MAC address• Error detection not correction• Move bits between devices• Specifies voltage, wire speed and
pin-out cables
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—2-11
802.3 / 802.2HDLC
EIA/TIA-232V.35
IPIPX
EXAMPLES
Role of Data Flow Layers
Network
Data Link
Physical
• Combines bits into bytes and bytes into frames
• Access to media using MAC address• Error detection not correction• Move bits between devices• Specifies voltage, wire speed and
pin-out cables
Provide logical addressing which routers use for path determination
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—2-12
TCPUDPSPX
802.3 / 802.2HDLC
EIA/TIA-232V.35
IPIPX
EXAMPLES
Role of Data Flow Layers
Transport
Data Link
Physical
• Reliable or unreliable delivery• Error correction before retransmit
• Combines bits into bytes and bytes into frames
• Access to media using MAC address• Error detection not correction• Move bits between devices• Specifies voltage, wire speed and
pin-out cables
Network Provide logical addressing which routers use for path determination
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—2-13
TCPUDPSPX
802.3 / 802.2HDLC
EIA/TIA-232V.35
IPIPX
Presentation
Application
SessionEXAMPLES
Role of Data Flow Layers
• Reliable or unreliable delivery• Error correction before retransmit
• Combines bits into bytes and bytes into frames
• Access to media using MAC address• Error detection not correction• Move bits between devices• Specifies voltage, wire speed and
pin-out cables
Transport
Data Link
Physical
Network Provide logical addressing which routers use for path determination
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—2-14
Encapsulating Data
Transport
Data Link
Physical
Network
Upper Layer Data
Upper Layer DataTCP Header
DataIP Header
DataLLC Header
0101110101001000010
DataMAC Header
Presentation
Application
Session
Segment
Packet
Bits
Frame
PDU
FCS
FCS
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—2-15
Upper Layer Data
De-encapsulating Data
LLC Hdr + IP + TCP + Upper Layer Data
MAC Header
IP + TCP + Upper Layer Data
LLC Header
TCP+ Upper Layer Data
IP Header
Upper Layer Data
TCP Header
0101110101001000010
Transport
Data Link
Physical
Network
Presentation
Application
Session
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—2-16
Application
Presentation
Session
Transport
Network
Data Link
Physical
OSI Model PDU Functional Responsibilities Examples
Written Exercise: OSI Model