U3 - NETWORKS Flashcards
PACKET CONTENTS
Error Check
Data
Return Address
Tracking Information
Sequence No.
Destination Address
SEQUENCE NO.
Tells the receiving device what order the packet goes in
TRACKING INFO
Allows the router to keep track of the data
ERROR CHECK
Authenticates the data / Makes sure it hasn’t been corrupted
RETURN ADDRESS
Contains the IP Address of the sending device in case an error occurs
DESTINATION ADDRESS
Says where the packet needs to go
NETWORK
A network consists of two or more devices that are connected together allowing them to communicate and exchange information
ROUTERS
Routers store all addresses of all the computers on a network. It can forward data to the correct destination.
PROTOCOLS
Protocols are agreed formats that allow networks to communicate.
EXAMPLE PROTOCOLS
Handshaking - When two devices establish a connection
How sending device indicates a message is over
How receiving device will indicate a message has been received
Agreement on data compressionmethod used
TCP/IP STACK
Physical layer
Data link layer
Network layer
Transport layer
Application Layer
PHYSICAL LAYER
Transmits raw data
Consists of cables and switches
Deals with all aspects of setting up and maintaining a link between computers
NIC CONNECTION
DATA LINK LAYER
Sends data from the network layer to the physical layer.
Divides data to be sent into DATA FRAMES
ETHERNET = PROTOCOL
NETWORK LAYER
Responsible for addressing and routing of data
ROUTERS belong to this layer as they use logical adresses to direct data from the sender to receiver
IP = PROTOCOL
TRANSPORT LAYER
Ensures data is reliably transferred for A to B without error.
Responsible for making sure data is sent and received in the right order
Transport layer is implemented in the sending and receiving computers but not in the routers on the path between them.
TCP = PROTOCOL