Topics + Self Study Assignments - Computer Networks CSE1405
CSE TU Delft - Lieke Sanders
Topic 1 - Introduction
Topic 2 - Data Link Layer
Topic 3 - MAC SubLayer
Topic 4 - Network Layer
Topic 5 - Transport Layer
Topic 6 - Application Layer
Topic 7 - Security
Self Study Assignment 1 - Error Detection and Correction
Self Study Assignment 2 - Cryptography
,Topic 1 - Introduction
Lecture 1
Tor = hides your identity (IP address) on the web
Obtaining relays
1 Publicly available list (default) (blocked)
- Download and choose randomly
- Easy to block
2 Private relays (bridges) (not all blocked)
- Set of relays not included in public list
- Changed frequently
- Can be requested (for example, by email)
- Only give out small number, not complete list
Protocols
- Algorithm for communication between two or more parties
- Defines the rules of communication
- Provides a service (function signature)
,Layers
There are layers in protocols that provide levels of abstraction, because every layer provides
a service that is only communicated to the layer above or below
Network layers are often the same layers on multiple machines, and only the lowest one
actually communicates
, Physical layer
Sends one bit via a physical medium like an ethernet cable
Data link layer
Sends a sequence of bits over a link reliably, like a phone sending data to a wifi router. Here,
reliability is needed, so there needs to be something in place to ensure that the data is sent
correctly
Network layer
Sends data from one computer in a network to another
Transport layer
Sends data in a reliable or unreliable way over an unreliable network
Application layer
Sends application-specific information over the network
CSE TU Delft - Lieke Sanders
Topic 1 - Introduction
Topic 2 - Data Link Layer
Topic 3 - MAC SubLayer
Topic 4 - Network Layer
Topic 5 - Transport Layer
Topic 6 - Application Layer
Topic 7 - Security
Self Study Assignment 1 - Error Detection and Correction
Self Study Assignment 2 - Cryptography
,Topic 1 - Introduction
Lecture 1
Tor = hides your identity (IP address) on the web
Obtaining relays
1 Publicly available list (default) (blocked)
- Download and choose randomly
- Easy to block
2 Private relays (bridges) (not all blocked)
- Set of relays not included in public list
- Changed frequently
- Can be requested (for example, by email)
- Only give out small number, not complete list
Protocols
- Algorithm for communication between two or more parties
- Defines the rules of communication
- Provides a service (function signature)
,Layers
There are layers in protocols that provide levels of abstraction, because every layer provides
a service that is only communicated to the layer above or below
Network layers are often the same layers on multiple machines, and only the lowest one
actually communicates
, Physical layer
Sends one bit via a physical medium like an ethernet cable
Data link layer
Sends a sequence of bits over a link reliably, like a phone sending data to a wifi router. Here,
reliability is needed, so there needs to be something in place to ensure that the data is sent
correctly
Network layer
Sends data from one computer in a network to another
Transport layer
Sends data in a reliable or unreliable way over an unreliable network
Application layer
Sends application-specific information over the network
