lecture 3 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Lecture 3 PowerPoint Presentation
Download Presentation
Lecture 3

Loading in 2 Seconds...

play fullscreen
1 / 18

Lecture 3 - PowerPoint PPT Presentation


  • 171 Views
  • Uploaded on

Lecture 3. Network Architecture. Host. Host. Application. Host. Channel. Application. Host. Host. Inter-Process Communication. Turn host-to-host connectivity into process-to-process communication. Fill gap between what applications expect and what the underlying technology provides.

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

PowerPoint Slideshow about 'Lecture 3' - minowa


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
lecture 3

Lecture 3

Network Architecture

Datacom 1

inter process communication

Host

Host

Application

Host

Channel

Application

Host

Host

Inter-Process Communication
  • Turn host-to-host connectivity into process-to-process communication.
  • Fill gap between what applications expect and what the underlying technology provides.

Datacom 1

channel protocol a simple example
Channel protocol, a simple example
  • Sender
    • Receives Data and destination from Application in Application’s format
    • Prepares and sends packets across the network with delivery guarantee—no guarantee about application data quality
    • Receives packets from network
  • Reciever
    • Sends and Receives Ack(nowledgements)
    • Sends Data to Application

Datacom 1

channel function sending side
Channel Function: Sending Side
  • Creates packets from message-segmentation
  • Marks packets alternately with 0 or 1
  • Attaches address of receiver
  • Sends next packet on (Ack)nowledgement
  • If 1 is sent and Ack is 0, resend
  • If 1 is sent and Ack is 1, send next
  • Etc.

Datacom 1

channel function receiving side
Channel Function: Receiving Side
  • Receive packets
  • Send Ack with 0 or 1 attached
  • Strip header
  • Reassemble message and send to application

Datacom 1

layering
Layering
  • Use abstractions to hide complexity
  • Abstraction naturally lead to layering

Datacom 1

layering1
Layering
  • Alternative abstractions at each layer

Application programs

Request/reply

Message stream

channel

channel

Host-to-host connectivity

Hardware

Datacom 1

protocols
Protocols
  • Building blocks of a network architecture
  • Provides communications service that higher level objects use to exchange messages
  • Each protocol object has two different interfaces
    • service interface: operations on this protocol
    • peer-to-peer interface: messages exchanged with peer
  • Term “protocol” is overloaded
    • Abstract object
    • specification of peer-to-peer interface
    • module that implements this interface-different implementations should be interoperable

Datacom 1

interfaces
Interfaces

Host1

Host2

Service

High-level

High-level

interface

object

object

Protocol

Protocol

Peer-to-peer

interface

Datacom 1

protocol machinery
Protocol Machinery
  • Protocol Graph
    • most peer-to-peer communication is indirect
    • peer-to-peer is direct only at hardware level

Host 2

Host 1

Applicationemploys services of protocol stack RPP/HHP

Asks

Invokes

Transmits

Digital

Digital

Video

Video

File

File

library

library

application

application

application

application

application

application

RRP

MSP

RRP

MSP

HHP

HHP

standards
Standards
  • Enternet Engineering Task Force (IETF)
  • International Standards Organization (ISO) +International Telecommunications Union (ITU)
  • Network Architecture-set of rules governing form and content of a protocol graph e.g. ISO or Internet Architecture

Datacom 1

machinery cont
Machinery (cont)
  • Multiplexing and Demultiplexing (demux key)
  • Encapsulation (header/body)

Host 1

Host 2

Header is a message to a peer not a lower level protocol

Application

Application

program

program

Data

Data

RRP

RRP

RRP

Data

RRP

Data

HHP

HHP

HHP

RRP

Data

iso or osi architecture osi open systems interconnection
ISO or OSI ArchitectureOSI= Open Systems Interconnection

End host

End host

Application

Application

Presentation

Presentation

Session

Session

Transport

Transport

Network

Network

Network

Network

Data link

Data link

Data link

Data link

Physical

Physical

Physical

Physical

One or more nodes

within the network

Datacom 1

typical osi services by layer
Typical OSI Services by Layer
  • Physical—transmission of raw bits
  • Data Link-transmission of frames—network adaptors and OS software implements this layer
  • Network- routing of packets
  • Transport-End host function-
  • Session-ties together transport streams-video+audio (obsolete)
  • Presentation-Data format etc. (obsolete)
  • Application layer-FTP, Video Conference etc.

Datacom 1

internet architecture

FTP

HTTP

NV

TFTP

UDP

TCP

IP

NET

NET

NET

2

1

n

Internet Architecture
  • Defined by Internet Engineering Task Force (IETF)
  • Hourglass Design
  • Application vs Application Protocol (FTP, HTTP)

Datacom 1

internet architecture services by layer
Internet architecture services by layer
  • Network
    • Ethernet—copper, network adapter, network device driver
    • Fiber Distributed Data Interface (FDDI)
  • IP-specifies interconnection of multiple networking technologies-creates single, unified network
  • Transport or end-to-end protocols
    • TCP reliable byte-stream channel
    • UDP Unreliable datagram delivery channel
  • Applications FTP, TFTP, SMATP, HTTP

Datacom 1

3 features of internet architecture
3-features of Internet Architecture
  • Strict layering is abandoned
  • IP is the big idea—a single protocol for interconnecting networks and providing host-to-host connectivity
  • To become a standard requires a working implementation

Datacom 1