protocol layering n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Protocol Layering PowerPoint Presentation
Download Presentation
Protocol Layering

Loading in 2 Seconds...

play fullscreen
1 / 19

Protocol Layering - PowerPoint PPT Presentation


  • 231 Views
  • Uploaded on

Sender. Receiver. Layer N. Layer N. Layer 2. Layer 2. Layer 1. Layer 1. Network. Protocol Layering. Motivation for Protocol Layering - The Programming Language Analogy. Computer programming: Program -> Compiler -> Assembly Code -> Assembler -> Machine Code -> Hardware

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

Protocol Layering


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
  1. Sender Receiver Layer N Layer N . . . . . . Layer 2 Layer 2 Layer 1 Layer 1 Network Protocol Layering

  2. Motivation for Protocol Layering - The Programming Language Analogy • Computer programming: • Program -> Compiler -> Assembly Code -> Assembler -> Machine Code -> Hardware • Internet programming: • Application -> Transport Protocol -> Connectionless Datagram Delivery Protocol -> Physical Network

  3. The Internet Protocol Suite • Internetworking does not use a single protocol to transmit data • Imagine how hard it would be to write one that: • Ran on all underlying network technologies • Transmitted and routed all traffic on the internet • Handled: hardware failure, network congestion, delays, data loss, data corruption, data duplication, sequencing errors • Internetworking uses a set of cooperating protocols (each with its own job)

  4. Benefits of Protocol Layering • Complexity hidden from application-level programmer • Physical network details hidden in low-level protocols • Each layer of software can be written, tested, and modified independently

  5. Sender Receiver Layer N Layer N . . . . . . Layer 2 Layer 2 Layer 1 Layer 1 Network Protocol Layering • Each layer provides services to the layer above and utilizes services from the layer below

  6. Send Recv Layer N Layer N . . . . . . Network (IP) Network (IP) Network 1 Network 2 Network 3 Data Link Layer Data Link Layer Data Link Layer Data Link Layer Physical Layer Physical Layer Physical Layer Physical Layer Protocol Layering • The path of a datagram:

  7. 7 6 Transport Layer Network Layer Data Link Layer Physical Layer Session Layer Presentation Layer Application Layer 5 4 3 2 1 Functionality of the Layers • ISO 7-Layer Reference Model:

  8. ISO 7-Layer Reference Model • Physical Layer (ISO Layer 1) • Service: transmission of a raw bit stream over a communication channel ensuring a reliable delivery of 0’s and 1’s • Functions: conversion of bits into electrical or optical signals • Examples: X.21, RS-232-C

  9. ISO 7-Layer Reference Model • Data Link Layer (ISO Layer 2) • Service: reliable transfer of frames over a link • Functions: synchronization, error control, flow control • Examples: HDLC, CCITT, LAP-D • Network Layer (ISO Layer 3) • Service: provide switching and routing functions to transfer data between hosts • Functions: routing, addressing, switching, congestion control • Examples: IP, X.25, CLNP

  10. ISO 7-Layer Reference Model • Transport Layer (ISO Layer 4) • Service: control delivery of messages between hosts • Functions: connection management, error control, flow control, multiplexing • Examples: TCP, UDP, ISO TP0 - TP4 • Session Layer (ISO Layer 5) • Service: support communication between cooperating application programs • Functions: session management, synchronization, recovery • Examples: ISO session protocol, RPC

  11. ISO 7-Layer Reference Model • Presentation Layer (ISO Layer 6) • Service: handle compatibility issues • Functions: virtual device support, syntax conversion, cryptography • Examples: ASN.1, ISO presentation protocol • Application Layer (ISO Layer 7) • Service: provide network access to application programs • Functions: (application specific) • Examples: Telnet, FTP, E-mail, WWW

  12. ISO 7-Layer Reference Model • Designed by committee - International Organization for Standardization (ISO) • Reference model, not an implementation • Implemented by a set of protocols known as X.25

  13. Network Interface Layer Hardware Internet Layer Transport Layer Application Layer Messages or Streams Transport Protocol Packets IP Datagrams Network-Specific Frames TCP/IP Internet Layering Model • Functionality of the layers Objects Passed Between Layers Conceptual Layer

  14. TCP/IP Internet Layering Model • Network Interface Layer (TCP/IP Layer 1) • Service: accepts IP datagrams and transmits them over a specific network • Functions: conversion of datagrams to physical frames • Examples: device drivers • Internet Layer (TCP/IP Layer 2) • Service: connectionless datagram delivery • Functions: inter-host communication, routing • Examples: IP

  15. TCP/IP Internet Layering Model • Transport Layer (TCP/IP Layer 3) • Service: provide reliable end-to-end communication • Functions: flow control, sequencing, acknowledgments • Examples: TCP • Application Layer (TCP/IP Layer 4) • Service: (application specific) • Functions: (application specific) • Examples: Telnet, FTP, E-mail, WWW

  16. Internet Model vs. ISO Model • Similarities • Differences

  17. Application Transport Internet Network Interface Transport Internet Network Interface The Protocol Layering Principle “Layered protocols are designed so that layer N at the destination receives exactly the same object sent by layer N at the source.” Application Identical message Identical packet Identical datagram Identical frame Network

  18. Conceptual Layer Network Interface Layer Internet Layer Transport Layer Application Layer Hardware Boundaries in the TCP/IP Model Boundary Software outside the operating system Software inside the operating system Only IP addresses used Physical addresses used

  19. Protocol Layering • Advantages • Disadvantages