W2L2 - OSI, TCP/IP Model Flashcards
What is the point of the OSI, TCP/IP model?
Give a way to divide responsibility in the network
Splits tasks and protocols separately to be dealt with individually
How does the Hierarchy work?
Each layer provides a service to the layer above through a standard interface
Application Layer
Provides services that are frequently required by the applications: DNS, file transfer, email
Presentation Layer
Present data in a consistent way, regardless of machine type
Session Layer
Opening a session dialog (resuming, pausing, stopping) between applications. Need to store a bit of station relating to session
Dialog, session structure, interpretation and recovery
Transport Layer
Ensure packets arrive and are in order. Segmentation and reassembly
Connection setup, maintenance and release
Network Layer
Delivery
Addressing
Routing
Data Link Layer
Group bits into frames and transfer them across direct connections
Detection of bit error; retransmission of frames
Flow control and addressing
Provides services that are frequently required by the applications: DNS, file transfer, email
Application Layer
Present data in a consistent way, regardless of machine type
Presentation Layer
Opening a session dialog (resuming, pausing, stopping) between applications. Need to store a bit of station relating to session
Dialog, session structure, interpretation and recovery
Session Layer
Ensure packets arrive and are in order. Segmentation and reassembly
Connection setup, maintenance and release
Transport Layer
Delivery
Addressing
Routing
Network Layer
Group bits into frames and transfer them across direct connections
Detection of bit error; retransmission of frames
Flow control and addressing
Data Link Layer
OSI order
Application > Presentation > Session > Transport > Network > Data Link > Physical
