CS 350Chapter-2

Advantages layered Model

Please Do Not Throw Sausage

Pizza AwayApplication

Provides a user interface

Presentation

Presents data, handles processing such as data encryption, compression

Session Keeps different applications’ data separate (simplex, half duplex, and full duplex)

Transport Provides reliable or unreliable delivery, performs error correction before retransmit (Conn-oriented, flow control)

Network Provides logical addressing, which routers use for path determination

Data Link Combines packets into bytes and bytes into frames, provides access to media using MAC address, performs error detection not correction

Physical Moves bits between devices, specifies voltage, wire speed, and pin-out of cables

TransportConnection-Oriented Communication

Virtual circuit

Sequencing

Acknowledgement

Flow control

Flow control

Windowing

Acknoledgement

NetworkingData packets

Route-update packets

Network address

Interface

Metric

RoutersDo not forward broadcast or multicast

Use IP address to forward packet to the next hop

Use access list, created by admin, to control security on the types of packets allowed to enter or exit

Can provide layer-2 bridging functions, and route through the same interface simultaneously

Layer-3 device, provide connection between VLAN

Provide QoS

The Data Link Layer

Media Access Control (MAC)Contention media access – first come first serve

Logical Link Control (LLC)Encapsulation

Flow control

Sequencing

IEEE 802 – LAN/MANs

802.2 --- LLC

802.3 --- CSMA/CD

802.11 – Wireless LAN

802.16 -- WiMAX

Physical LayerBit patterns

Encoding bits

Interfaces

Physical topology

Encapsulation