State the name of each layer in the ISO seven-layer model
Layer 7 - Application
Layer 6 - Presentation
Layer 5 - Session
Layer 4 - Transport
Layer 3 - Network
Layer 2 - Data Link
Layer 1 - Physical
Give some disadvantages of standardizing
Standardizing when research is incomplete, thus leading to poor standards.
Standards can be overly complex and thus restrictive on new people entering the market.
Standards may be incomplete.
Standards may become irrelevant as technology advances.
State the purpose of the Physical layer in ISO seven-layer network model.
Bit transmission across some sort of transmission meidum
State the purpose of the Data Link layer in ISO seven-layer network model.
Blocking bits together to control flow and checking that they arrived correctly
State the purpose of the Network layer in ISO seven-layer network model.
Routing blocks of bits through a network
State the purpose of the Transportlayer in ISO seven-layer network model.
Receives the blocks at the destination (and passes them to the right application)
State the purpose of the Session layer in ISO seven-layer network model.
Synchronization and Dialogue control. Managing sessions between applications.
State the purpose of the Presentation layer in ISO seven-layer network model.
Syntax and semantics of the information. (Encrypting / Decrypting, Data representation)
State the purpose of the Applicationlayer in ISO seven-layer network model.
Common applications
Name the internet layers
Application Layer
Transport Layer
Internet Protocol Layer
Network Interface Layer
Physical Net Layer
Which layers of the Intenet model correspond with that of the OSI seven-layer model.
Internet Application - OSI Application
Internet Application - OSI Presentation
Internet Application - OSI Session
Internet Transport - OSI Transport
Internet Internet Protocol - OSI Network
Internet Network Interface - OSI Data Link
Internet Physical - OSI Physical
Why is layering (abstraction) a good idea?
Focus on the individual processes
Debugging and maintenance is easier
What is a protocol?
"A set of rules and regulations agreed by two parties in order to govern communication."
What is framing and why is it used?
It is where a raw bit stream is broken up into groups of bits (called frames). This is to enable error and flow control.
Data Link Protocol: What would be an unrestricted protocol?
A protocol whereby the sender could send frames as fast as it wanted. (Unrestricted send speed)
Data Link Protocol: What would be a restricted protocol?
(Stop-and-wait protocol)
Sender sends a frame and then waits for an acknowledgement (ACK)
Receiver waits for a frame and then sends an acknowledgement (ACK) when it has received one.
Data Link Protocol: What is put in place to help tackle a noisy channel?
Sender times out if it doesn't receive an acknowledgement (ACK). It will then re-send the same frame.
We use sequence numbers so that the receiver can check that the expected frame has been received. The receiver then sends an acknowledgement (ACK) back to the sender.
Author
Anonymous
ID
212856
Card Set
CO526 Distributed Systems and Networks
Description
Revision cards for CO526 Distributed Systems and Networks