Network topologies Flashcards
Will Every computer on a network have an IP address?
Yes
How does packet switching operate?
- A file is split into data packets
- Routers follow the IP rules and direct data packets towards their destination.
- Due to network traffic, packet switching may occur where the packets may take different routes and be directed to other routers before arriving at the destination.
- If the packets are in the wrong order, the sequence number can be used to reorder them back into the original file.
What is a protocol and why are they needed?
Protocols are rules that computers follow when transmitting and receiving data over a network.
They are needed to ensure that to ensure computers on a network can understand each others so that
1. data is sent and received correctly
2. data is sent to the correct place
what is SSID?
Stands for “Service Set Identifier.” An SSID is a unique ID that consists of 32charactersand is used for namingwirelessnetworks. When multiple wireless networks overlap in a certain location, SSIDs make sure that data gets sent to the correct destination.
Devices on a wireless network send and receive data using?
standard radio frequency bands
What is the IMAP – Internet Message Access Protocol?
IMAP – Internet Message Access Protocol
This is similar to POP but with one important difference. With IMAP, the email will remain on the server once it has been downloaded by a mail client. This allows other devices to also access the emails which is important for users with multiple devices – they can synchronise their emails across all devices.
What are the features of an Ethernet - STAR topology?
Twisted pair cabling allows duplex transmission (signal can travel in both directions at the same time)
Doesn’t need CSMA/CD protocol
What must happen to data broadcasted on a wireless network?
Data must be encrypted when broadcasted on a wireless network
Devices can communicate with each other when …?
Devices can communicate with each other when
The use the same frequency and channel
What do we call an a 32 bit number written as 4 decimal numbers eg: 129.168.1.101
IP address
what are the features of an Ethernet - BUS topology?
Shared backbone
Used CSMA/CD protocol
Device listens to the line prior to transmission
Stops if it detects a transmission on the line
Repeats the attempt after a random period of time
what are the Advantages
of using wireless networks?
Advantages
Easier to set up so less expensive
Can move around and access the network from anywhere
Can handle large numbers of users
Mesh topology
This is a fully connected network;
Every node is connected to all others;
This means that if a cable breaks or if there is heavy traffic on one area, there are other routes for the data to take
BUT:
It can be a very expensive set up due to the cabling required
What has the following?: 1. Header Destination IP address Source IP address A sequence number 2. The data itself 3. A checksum which is used for error checking
A data packet
partial mesh topology
Some, but not all computers are connected to each other
There are still alternative routes between computers
It is an effective compromise between cabling cost and effective communications
What is a hardware identification number that uniquely identifies each device on a network.
A MAC address
If you have your documents / files stored on a file server, the way you access them will be governed by the xxxx xxxxxxxx xxxxxxxx? This standard (XXX) ensure that all clients (computers) on a network can access files from a server in the same way.
FTP – File Transfer Protocol
Cables (wired)
There are two main types of cable which can transport data between computers.
they are?
Cables (wired)
There are two main types of cable which can transport data between computers.
Ethernet Cables
These are made up of copper wires with the data being transported via electrical signals. Because they carry electrical signals, they can suffer from interference.
Fibre Optic Cables
These are made up of glass fibres with the data being transported via light signals.
Fibre optic cables are more effective…nothing travels faster than the speed of light! They also do not suffer from interference.
They are however more expensive that Ethernet cables.
Devices on a wireless network send and receive data using standard radio frequency bands:
what bands?
Devices on a wireless network send and receive data using standard radio frequency bands:
2.4 GHz Band (frequencies between 2.4GHz & 2.5GHz)
5 GHz Band (frequencies between 5.725GHz & 5.875GHz)
Each band is split into channels that cover smaller frequency ranges, within the band.
The TCP (Transmission Control Protocol) defines the rules for sending data packets on the Internet It ensures that?? (3 Things)
The TCP defines the rules for sending data packets on the Internet
It ensures that
all data is split up into data packets in the same way.
the data packets are put back together when received by the destination device.
any data received is the same as that sent.
What are Ethernet Cables made of?
Ethernet Cables
These are made up of copper wires with the data being transported via electrical signals. Because they carry electrical signals, they can suffer from interference.
what are the Disadvantages
of using wireless networks?
Disadvantages Slower than a wired network Relies on signal strength to WAP Signal can be obstructed Less secure than a wired network
How does the encryption process work?
Encryption process works as follows
data is converted into cipher text prior to transmission using a key created using the SSID and the password
the data is decrypted by the receiver using the same key
What is a hardware identification number that uniquely identifies each device on a network.
MAC address
