ﺑﺴﻢﺍﻟﻠﻪﺍﻟﺮﺣﻤﻦﺍﻟﺮﺣﻴﻢ ﺷﺒﻜﻪﻫﺎﻱ ﻛﺎﻣپﻴﻮﺗﺮﻱ 1 ﻣﻬﻨﺪﺱ ﻣﺤﻤﻮﺩ ﻋﻠیﺸﺎﻫی

ﺑﺴﻢﺍﻟﻠﻪﺍﻟﺮﺣﻤﻦﺍﻟﺮﺣﻴﻢ ﺷﺒﻜﻪﻫﺎﻱ ﻛﺎﻣپﻴﻮﺗﺮﻱ 1 ﻣﻬﻨﺪﺱ ﻣﺤﻤﻮﺩ ﻋﻠیﺸﺎﻫی ﻧﻴﻤﺴﺎﻝ ﺩﻭﻡ 78 -68

ﺳﺮ ﻓﺼﻞ ﺩﺭﺱ ﺷﺒﻜﻪﻫﺎﻱ ﻛﺎﻣپﻴﻮﺗﺮﻱ 1 ﻓﺼﻞ ﺍﻭﻝ: ﻣﻘﺪﻣﻪ • ﺷﺒﻜﻪﻫﺎﻱ ﻛﺎﻣپﻴﻮﺗﺮﻱ چﻪ ﻫﺴﺘﻨﺪ؟ • ﺷﺒﻜﻪﻫﺎﻱ ﻛﺎﻣپﻴﻮﺗﺮﻱ چﻪ ﺍﺟﺰﺍﻳﻲ ﺩﺍﺭﻧﺪ؟ • ﺷﺒﻜﻪﻫﺎﻱ ﻛﺎﻣپﻴﻮﺗﺮﻱ ﺑﻪ چﻪ ﻛﺎﺭﻱ ﻣﻲآﻴﻨﺪ؟ • ﻻﻳﻪﻫﺎﻱ ﻣﺨﺘﻠﻒ ﻛﺎﺭ ﺷﺒﻜﻪ: ﺍﺳﺘﺎﻧﺪﺍﺭﺩﻫﺎﻱ (Do. D )TCP/IP،ISO/OSI ﻭ Novell Netware

ﺳﺮ ﻓﺼﻞ ﺩﺭﺱ ﺷﺒﻜﻪﻫﺎﻱ ﻛﺎﻣپﻴﻮﺗﺮﻱ 1 ﻓﺼﻞ ﺩﻭﻡ: ﺑﺮﺭﺳﻲ ﻻﻳﺔ ﻓﻴﺰﻳﻜﻲ • ﺧﺼﻮﺻﻴﺎﺕ ﻣﺤﻴﻂ ﺍﻧﺘﻘﺎﻝ • ﻛﺪﻳﻨگ ﺩﺍﺩﻩﻫﺎ ﻓﺼﻞ ﺳﻮﻡ: ﺑﺮﺭﺳﻲ ﻻﻳﺔ ﺍﺭﺗﺒﺎﻁ ﺩﺍﺩﻩ • پﺮﻭﺗﻜﻞﻫﺎﻱ MAC ﻭ LLC • ﺭﻭﺵﻫﺎﻱ ﻛﻨﺘﺮﻝ ﺟﺮﻳﺎﻥ ﺩﺍﺩﻩ • ﺗﺸﺨﻴﺺ ﺧﻄﺎﻱ ﺩﺍﺩﺓ ﺍﺭﺳﺎﻟﻲ • ﺗﺼﺤﻴﺢ ﺧﻄﺎﻱ ﺩﺍﺩﻩ ﺩﺭ گﻴﺮﻧﺪﻩ

ﺳﺮ ﻓﺼﻞ ﺩﺭﺱ ﺷﺒﻜﻪﻫﺎﻱ ﻛﺎﻣپﻴﻮﺗﺮﻱ 1 ﻓﺼﻞ چﻬﺎﺭﻡ: ﺑﺮﺭﺳﻲ ﻻﻳﺔ ﺷﺒﻜﻪ • پﺮﻭﺗﻜﻞﻫﺎ ﻭ ﺍﺳﺘﺎﻧﺪﺍﺭﺩﻫﺎﻱ ﻻﻳﺔ ﺷﺒﻜﻪ • ﺷﺒﻜﻪﻫﺎﻱ LAN ﻭ MAN ﻭ WAN ﻓﺼﻞ پﻨﺠﻢ: ﺑﺮﺭﺳﻲ ﻻﻳﺔ ﺍﻧﺘﻘﺎﻝ ﻭ ﺟﻠﺴﻪ • ﺍﺭﺗﺒﺎﻁ ﺩﺍﺧﻠﻲ ﺷﺒﻜﻪﻫﺎﻱ ﺑﺎ ﺳﻮﺋﻴچﻴﻨگ ﺑﺴﺘﻪﺍﻱ

ﺳﺮ ﻓﺼﻞ ﺩﺭﺱ ﺷﺒﻜﻪﻫﺎﻱ ﻛﺎﻣپﻴﻮﺗﺮﻱ 1 ﻓﺼﻞ ﺷﺸﻢ: ﺑﺮﺭﺳﻲ ﻻﻳﺔ ﺍﺭﺍﺋﻪ • ﺍﻣﻨﻴﺖ ﻭ ﺣﻔﺎﻇﺖ ﺩﺍﺩﻩﻫﺎ • ﺗﻜﻨﻴﻚﻫﺎﻱ ﻓﺸﺮﺩﻩﺳﺎﺯﻱ ﺩﺍﺩﻩﻫﺎ • پﺮﻭﺗﻜﻞ ﺗﺮﻣﻴﻨﺎﻝ ﻣﺠﺎﺯﻱ • پﺮﻭﺗﻜﻞ ﺍﻧﺘﻘﺎﻝ ﻓﺎﻳﻞ • ﻭ. . .

ﺳﺮ ﻓﺼﻞ ﺩﺭﺱ ﺷﺒﻜﻪﻫﺎﻱ ﻛﺎﻣپﻴﻮﺗﺮﻱ 1 ﻓﺼﻞ ﻫﻔﺘﻢ: ﺑﺮﺭﺳﻲ ﻻﻳﺔ ﻛﺎﺭﺑﺮﺩ • ﺳﻴﺴﺘﻢﻫﺎﻱ ﺩﺍﺩﺓ ﺗﻮﺿﻴﻊ ﺷﺪﻩ ﻭ ﺍﺭﺗﺒﺎﻁ آﻨﻬﺎ • ﺳﻴﺴﺘﻢﻫﺎﻱ ﻋﺎﻣﻞ ﺷﺒﻜﻪ

ﻓﺼﻞ ﺍﻭﻝ: ﻣﻘﺪﻣﻪ ﺷﺒﻜﻪﻫﺎﻱ ﻛﺎﻣپﻴﻮﺗﺮﻱ چﻪ ﻫﺴﺘﻨﺪ؟ ﺑﻪ ﻣﺠﻤﻮﻋﻪﺍﻱ ﺍﺯ ﺳﺨﺖﺍﻓﺰﺍﺭﻫﺎ، ﻧﺮﻡﺍﻓﺰﺍﺭﻫﺎ، ﺗﻔﻜﻴﻚﻫﺎ )ﻣﺤﻴﻂ ﺍﺭﺗﺒﺎﻃﻲ( ﻭ پﺮﻭﺗﻜﻞﻫﺎ ﻛﻪ ﺣﺪﺍﻗﻞ ﺩﻭ ﻛﺎﻣپﻴﻮﺗﺮ ﺭﺍ ﺑﻪ ﻫﻤﺪﻳگﺮ ﻣﺮﺗﺒﻂ ﻛﻨﻨﺪ، ﺷﺒﻜﻪﻫﺎﻱ ﻛﺎﻣپﻴﻮﺗﺮﻱ گﻮﻳﻨﺪ.

ﻓﺼﻞ ﺍﻭﻝ: ﻣﻘﺪﻣﻪ ﺗﺎﺭﻳﺨچﺔ ﺷﺒﻜﻪﻫﺎﻱ ﻛﺎﻣپﻴﻮﺗﺮﻱ • ﺷﺒﻜﻪﻫﺎﻱ ﻛﺎﻣپﻴﻮﺗﺮﻱ ﺷﻜﻞ ﺗﻐﻴﻴﺮ ﻳﺎﻓﺘﻪﺍﻱ ﺍﺯ ﺷﺒﻜﻪﻫﺎﻱ ﺍﺭﺗﺒﺎﻃﻲ ﻫﺴﺘﻨﺪ ﻛﻪ ﻣﻨﻈﻮﺭ ﺍﺻﻠﻲ ﺍﺯ آﻨﻬﺎ ﺗﺒﺎﺩﻝ ﺩﺍﺩﺓ ﺩﻳﺠﻴﺘﺎﻝ ﺩﺭ ﻗﺎﻟﺐ ﻓﺎﻳﻠﻬﺎ ﻭ ﻛﻴﺘﻬﺎﻱ ﻗﺎﺑﻞ ﻧگﻬﺪﺍﺭﻱ ﺑﻪ ﺷﻜﻞ ﺩﻳﺠﻴﺘﺎﻝ ﺍﺳﺖ. • ﺷﺒﻜﻪﻫﺎﻱ ﺩﺍﺩﻩ ﻋﻤﺪﺗ ﺍﺯ 03 ﺳﺎﻝ پﻴﺶ ﺑﻪ ﺍﻳﻦ ﻃﺮﻑ ﺭﺍﻳﺞ ﻭ ﻛﺎﺭﺑﺮﺩﻱ ﺷﺪﻩﺍﻧﺪ. • ﺩﺭ ﺍﻳﻦ ﺩﺭﺱ ﺷﺒﻜﻪﻫﺎﻳﻲ ﺑﺮﺭﺳﻲ ﻣﻲﺷﻮﻧﺪ ﻛﻪ ﺩﺭ ﺭﺍﺳﺘﺎﻱ ﻣﻨﻈﻮﺭ ﻳﺎﺩ ﺷﺪﻩ ﺑﺎﺷﻨﺪ.

ﻓﺼﻞ ﺍﻭﻝ: ﻣﻘﺪﻣﻪ ﺷﺒﻜﻪﻫﺎﻱ ﻛﺎﻣپﻴﻮﺗﺮﻱ چﻪ ﺍﺟﺰﺍﻳﻲ ﺩﺍﺭﻧﺪ؟ 1 ﺳﺨﺖﺍﻓﺰﺍﺭ: ﻣﺎﺷﻴﻦ ) (HOST ﻳﻚ گﺮﻩ ﻛﺎﻣﻞ، ،Gateway Bridge،Router ﻭ Repeater 2 ﻭﺳﻴﻠﺔ ﺍﺭﺗﺒﺎﻃﻲ: ﻛﺎﺑﻞ ﻛﻮﺍﻛﺴﻴﺎﻝ، ﻛﺎﺑﻞ ﺯﻭﺟﻲ، ﻓﻴﺒﺮ ﻧﻮﺭﻱ، ﻣﺎﻳﻜﺮﻭﻭﻳﻮ، ﻣﺎﻫﻮﺍﺭﻩ ﻭ ﺭﺍﺩﻳﻮ 3 پﺮﻭﺗﻜﻞﻫﺎﻱ -4 ﺑﺮﻧﺎﻣﻪﻫﺎﻱ ﺍﺭﺗﺒﺎﻃﻲ: ، X. 25، Netware،TCP/IP X. 75،LAP ﻭ ISO/OSI ﻛﺎﺭﺑﺮﺩﻱ: ، Tel. Net، FTP،Netscape Mail ﻭ. . .

ﻓﺼﻞ ﺍﻭﻝ: ﻣﻘﺪﻣﻪ ﺍﺟﺰﺍﻱ ﺷﺒﻜﻪﻫﺎﻱ ﻛﺎﻣپﻴﻮﺗﺮﻱ • ﺳﻴﺴﺘﻤﻬﺎﻱ ﺍﺑﺘﺪﺍﻳﻲ ﻭ ﺍﻧﺘﻬﺎﻳﻲ )ﺭﺍﻳﺎﻧﻪﻫﺎﻳﻲ ﻛﻪ ﺑﻪ آﻨﻬﺎ host گﻔﺘﻪ ﻣﻲﺷﻮﺩ، ﻭ ﻳﺎ پﺎﻳﺎﻧﻪﻫﺎﻳﻲ ﻛﻪ ﻗﺎﺑﻠﻴﺖ ﺍﺭﺳﺎﻝ ﻭ ﺩﺭﻳﺎﻓﺖ، پﺮﺩﺍﺯﺵ، ﻭ ﻧگﻬﺪﺍﺭﻱ ﺩﺍﺩﻩﻫﺎ ﺭﺍ ﺩﺍﺭﻧﺪ( • ﺍﺩﻭﺍﺕ ﺍﺭﺗﺒﺎﻃﻲ ﺑﻴﻦ ﺳﻴﺴﺘﻤﻬﺎﻱ ﺍﺑﺘﺪﺍﻳﻲ ﻭ ﺍﻧﺘﻬﺎﻳﻲ ﺷﺎﻣﻞ: – ﺍﺟﺰﺍﺀ ﻓﻌﺎﻝ،ﻧﻈﻴﺮ ﺍﺟﺰﺍﻱ ﺍﺭﺳﺎﻝ ﻭ ﺩﺭﻳﺎﻓﺖ ﺳﻴگﻨﺎﻝ، ﺗﻜﺮﺍﺭ ﻛﻨﻨﺪﻩ، پﻞ، ﺳﻮﺋﻴچ،ﺭﻭﺗﺮ، ﺍﺩﺍﻭﺍﺕ پﺮﺩﺍﺯﺷگﺮ ﺩﻳگﺮ – ﺍﺟﺰﺍﺀ ﻏﻴﺮ ﻓﻌﺎﻝ، ﻧﻈﻴﺮ ﻣﺤﻴﻄﻬﺎﻱ ﺍﺭﺗﺒﺎﻃﻲ ﻭ ﺍﺗﺼﺎﻻﺕ

ﻓﺼﻞ ﺍﻭﻝ: ﻣﻘﺪﻣﻪ ﺷﺒﻜﻪﻫﺎﻱ ﻛﺎﻣپﻴﻮﺗﺮﻱ ﺑﻪ چﻪ ﻛﺎﺭ ﻣﻲآﻴﻨﺪ؟ 1 ﺍﺳﺘﻔﺎﺩﺓ ﺍﺷﺘﺮﺍﻛﻲ ﺍﺯ ﻣﻨﺎﺑﻊ ﺳﺨﺖﺍﻓﺰﺍﺭﻱ ﻭ ﻧﺮﻡﺍﻓﺰﺍﺭﻱ: ﺳﺨﺖﺍﻓﺰﺍﺭ )ﻧﻈﻴﺮ: ﺍﺳﻜﻨﺮ، پﺮﻳﻨﺘﺮ، ﻓﻜﺲ ﻣﻮﺩﻡ ﻭ ﻏﻴﺮﻩ( ﻭ ﻧﺮﻡﺍﻓﺰﺍﺭ )ﻧﻈﻴﺮ: ﺩﺍﺩﻩ، پﻴﺎﻡ، ﻓﻮﻟﺪﺭ، ﻓﺎﻳﻞ ﻭ ﻏﻴﺮﻩ( 2 ﺗﺒﺎﺩﻝ ﺩﺍﺩﻩ ﺑﻴﻦ پﺎﻳگﺎﻩﻫﺎﻱ ﻣﺨﺘﻠﻒ ﺩﺍﺩﻩ 3 ﺍﺳﺘﻔﺎﺩﻩ ﺍﺯ ﺍﻣﻜﺎﻧﺎﺕ ﺳﺨﺖﺍﻓﺰﺍﺭﻱ ﺑﻪ ﺻﻮﺭﺕ ﺗﻮﺯﻳﻊ ﺷﺪﻩ -4 ﺍﺳﺘﻔﺎﺩﺓ ﺑﻬﺘﺮ ﺍﺯ ﺍﻣﻜﺎﻧﺎﺕ ﻗﻮﻱ ﻣﺎﺷﻴﻦﻫﺎﻱ ﻣﺴﺘﻘﺮ ﺩﺭ ﺩﻭﺭ ﺩﺳﺖ

Communication Model Network Source Destination

Simplified Communication Model

Simplified Data Communications Model

Simplified Network Model

ﻓﺼﻞ ﺍﻭﻝ: ﻣﻘﺪﻣﻪ ﺍﺳﺘﺎﻧﺪﺍﺭﺩﻫﺎﻱ ISO/OSI

Open Systems Interconnection (OSI) • Developed by the International Organization for Standardization (ISO) in 1984 • The primary architectural model for intercomputer communications. • A conceptual model composed of seven layers, each specifying particular network functions. • Describes how information from a software application in one computer moves through a network medium to a software application in another computer.

OSI ﻓﻌﺎﻟیﺘﻬﺎی ﻣﻮﺭﺩ ﻧیﺎﺯ ﺩﺭ ﺍﺳﺘﻔﺎﺩﻩ ﺍﺯ ﻣﺪﻝ Encapsulation Segmentation and reassmebly Connection control Ordered delivery Flow control Error control Addressing Multiplexing Transmission services • • •

ﺭﺍ ﺑﺮﺭﺳی ﻣی کﻨیﻢ؟ OSI چﺮﺍ ﻣﺪﻝ Still an excellent model for conceptualizing and • understanding protocol architectures Key points: • Modular – Hierarchical – Boundaries between layers=interfaces –

ISO’s OSI Model OSI has 7 layers: Application layer – Presentation layer – Session layer – Transport layer – Network layer – Data link layer – Physical layer –

ﺩﺍﺩﻩ ﻭ ﺳﺮآیﻨﺪ ﺩﺭ ﻫﺮ ﻻیﻪ یک PDU ﺗﺸکیﻞ ﻣی گﺮﺩﺩ کﻪ ﺷﺎﻣﻞ ﺍﺟﺰﺍی ﻣﻮﺭﺩ ﻧیﺎﺯ ﺑﺮﺍی ﺍﻧﺠﺎﻡ ﻓﻌﺎﻟیﺘﻬﺎی ﻣﻮﺭﺩ ﻧﻈﺮ ﺩﺭ آﻦ ﻻیﻪ ﺍﺳﺖ. PDU = Protocol Data Unit

OSI Lower Layers Physical – Layer 1 • Responsible for transmission of bits – Always implemented through hardware – Encompasses mechanical, electrical, and functional – interfaces e. g. RS-232 – Data Link – Layer 2 • Responsible for error-free, reliable transmission of data – Flow control, error correction – e. g. Ethernet – Network – Layer 3 • Responsible for routing of messages through network – Concerned with type of switching used (circuit v. packet) – Handles routing between networks, as well as through – packet-switching networks

ﻓﺼﻞ ﺍﻭﻝ: ﻣﻘﺪﻣﻪ ﻭﻇﺎﺋﻒ ﻻﻳﻪﻫﺎﻱ ﻫﻔﺖگﺎﻧﻪ ﺩﺭ ﻣﺪﻝ : OSI 1 ﻻﻳﺔ ﻓﻴﺰﻳﻜﻲ: • ﺗﻌﺮﻳﻔﻲ ﺑﺮﺍﻱ ﺍﺭﺳﺎﻝ ﺻﻔﺮ ﻭ ﻳﻚ ﺩﺭ ﻳﻚ ﻣﺤﻴﻂ ﺍﺭﺗﺒﺎﻃﻲ • ﺗﻌﻴﻴﻦ ﻣﺸﺨﺼﺎﺕ ﺍﻟﻜﺘﺮﻳﻜﻲ ﻭ ﻣﻜﺎﻧﻴﻜﻲ ﻭ ﻧﻴﺰ ﺗﺮﺗﻴﺐ ﺍﺟﺰﺍﻱ ﻓﻴﺰﻳﻜﻲ • ﺍﺳﺘﺎﻧﺪﺍﺭﺩﻫﺎﻱ ﻣﻮﺟﻮﺩ ﺩﺭ ﺍﻳﻦ ﻻﻳﻪ: Ethernet ﻭ ) RS-232 (E 1 A-23 A-D ﻭ. . . • ﺍﺳﺘﺎﻧﺪﺍﺭﺩﻫﺎﻱ ﻣﺮﺑﻮﻁ ﺑﻪ ﻣﻮﺩﻡ: 12 V 42، V 34، V 26،V 23 ،V ﻭ. . .

ﻓﺼﻞ ﺍﻭﻝ: ﻣﻘﺪﻣﻪ ﻭﻇﺎﺋﻒ ﻻﻳﻪﻫﺎﻱ ﻫﻔﺖگﺎﻧﻪ ﺩﺭ ﻣﺪﻝ : OSI 2 ﻻﻳﺔ ﺍﺭﺗﺒﺎﻁ ﺩﺍﺩﻩ: • ﻛﻨﺘﺮﻝ ﺍﺭﺳﺎﻝ ﺩﺍﺩﻩ ﺩﺭ ﺭﻭﻱ ﻳﻚ ﻣﺤﻴﻂ ﺍﺭﺗﺒﺎﻃﻲ • ﻛﻨﺘﺮﻝ ﺟﺮﻳﺎﻥ ﺩﺍﺩﻩﻫﺎ • ﻛﻨﺘﺮﻝ ﺧﻄﺎ • ﻛﻨﺘﺮﻝ ﺍﺭﺗﺒﺎﻁ ﺩﻫﻲ • ﺍﺳﺘﺎﻧﺪﺍﺭﺩﻫﺎﻱ ﻣﻮﺟﻮﺩ ﺩﺭ ﺍﻳﻦ ﻻﻳﻪ: ) HDLC (Higher Level Data Link Control LAP-B • ﻛﻨﺘﺮﻝ ﺧﻄﺎ

ﻓﺼﻞ ﺍﻭﻝ: ﻣﻘﺪﻣﻪ ﻭﻇﺎﺋﻒ ﻻﻳﻪﻫﺎﻱ ﻫﻔﺖگﺎﻧﻪ ﺩﺭ ﻣﺪﻝ : OSI 2 ﻻﻳﺔ ﺷﺒﻜﻪ: • ﻛﻨﺘﺮﻝ آﺪﺭﺱ ﻣﻘﺼﺪ • ﺍﺭﺳﺎﻝ ﻣﺠﺪﺩ ﺩﺍﺩﻩ • پﺮﻭﺗﻜﻞﻫﺎﻱ ﻣﻮﺟﻮﺩ ﺩﺭ ﺍﻳﻦ ﻻﻳﻪ: ﻧﻈﻴﺮ 52. X ﻭ IP

*Physical-layer Implementation

OSI Data Link Layer Responsible for error-free, reliable transmission of data • Flow control, error correction • e. g. HDLC •

OSI Data Link Layer IEEE has subdivided data link layer into two sub-layers.

OSI Network Layer Responsible for routing of messages through network • Concerned with type of switching used (circuit v. packet) • Handles routing between networks, as well as through • packet-switching networks

Network Access Layer Concerned with exchange of data between computer and network Includes addressing, routing, prioritizing, etc Different networks require different software at this layer Example: X. 25 standard for network access procedures on packet-switching networks • •

OSI Upper Layers Transport Isolates messages from lower and upper layers – Breaks down message size – Monitors quality of communications channel – Selects most efficient communication service necessary for a given – transmission Session Establishes logical connections between systems – Manages log-ons, password exchange, log-offs – Terminates connection at end of session – Presentation Provides format and code conversion services – Example: File conversion from ASCII to EBDIC – Application Provides access to network for end-user – User’s capabilities are determined by what items are available on – this layer Logic needed to support various applications – Each type of application requires different software on this layer – • •

ﻓﺼﻞ ﺍﻭﻝ: ﻣﻘﺪﻣﻪ ﻭﻇﺎﺋﻒ ﻻﻳﻪﻫﺎﻱ ﻫﻔﺖگﺎﻧﻪ ﺩﺭ ﻣﺪﻝ : OSI 4 ﻻﻳﺔ ﺍﻧﺘﻘﺎﻝ: • ﻙ

ﻣﺪﻟﻬﺎی ﺩیگﺮ ﺍﺭﺗﺒﺎﻃی؟ • ﻣﺪﻝ ) Do. D چﺮﺍ ﺍیﻦ ﺍﺳﻢ ﺭﺍ گﺬﺍﺷﺘﻪ ﺍﻧﺪ؟( یﺎ TCP/IP • ﻣﺪﻝ ﺍﺭﺗﺒﺎﻃی Novell یﺎ IPX/SPX • ﻣﺪﻝ ﺍﺭﺗﺒﺎﻃی Appletalk

TCP/IP Transmission control Protocol/Internet Protocol Developed by DARPA No official protocol standard Can identify four layers Application – Host-to-Host (transport) – Internet – Host to Network – • •

Do. D پﺮﻭﺗکﻠﻬﺎی ﻣﺨﺘﻠﻒ ﺩﺭ ﻣﺪﻝ Application Presentation Session Transport TELNET FTP SMTP DNS SNMP DHCP RIP RTCP Transmission Control Protocol User Datagram Protocol OSPF ICMP IGMP Internet Protocol Network ARP Host to Network Ethernet Token Bus Token Ring FDDI

Do. D ﻭ ISO ﻣﻘﺎیﺴﻪ ﻣﺪﻟﻬﺎی Do. D Model OSI Model Application layer: http, telnet, snmp, smtp, nfs, ftp TCP, UDP IPv 4, IPv 6 (HDLC) Host to Network

Sender Application Layer Transport Layer Network Layer Data Link Layer Physical Layer Receiver HTTP TCP HTTP Application Layer Request IP TCP HTTP Ethernet IP Transport Layer Request TCP HTTP Request Network Layer Data Link Layer Physical Layer HTTP Request TCP HTTP Request IP TCP HTTP Ethernet IP Request TCP HTTP Request

Do. D ﻻیﻪ ﺍﺗﺼﺎﻝ ﻣﺎﺷیﻦ ﺑﻪ ﺷﺒکﻪ ﺩﺭ ﻣﺪﻝ Exchange of data between end system and network Address of host and destination Prioritization of transmission Software at this layer depends on network (e. g. X. 25 vs. Ethernet) Segregation means that no other software needs to be concerned about net specifics • • •

TCP/IP Internet Layer An Internet is an interconnection of two or more networks Internet layer handles tasks similar to network access layer, but between networks rather than between nodes on a network Uses IP for addressing and routing across networks Implemented in workstations and routers • •

TCP/IP Transport Layer Also called host-to-host layer • Reliable exchange of data between applications • Uses TCP protocols for transmission •

TCP/IP Application Layer Logic needed to support variety of • applications Separate module supports each type of • application (e. g. file transfer) FTP – HTTP – Telnet – News – SMTP –

TCP & UDP Most TCP/IP applications use TCP for • transport layer TCP provides a connection (logical • association) between two entities to regulate flow check errors UDP (User Datagram Protocol) does not • maintain a connection, and therefore does not guarantee delivery, preserve sequences, or protect against duplication