Topic 1: Networks Flashcards
State 3 factors that influence the choice of a network for a company.
Budget (cost of hardware equipment, software licenses, and cabling, skilled staff)
Coverage (geographic area eg WAN or LAN)
Size (number of users)
How the network will be used (eg high quality video streaming vs email)
Performance: speed required in in megabytes or gigabytes per second and reliability (for example, the network should work 99.9% of the time)
[Security level - the exam board has removed this answer! It won’t be allowed anymore.]
Define a peer-to-peer network
A peer-to-peer network has no server. All PCs have the same status and they communicate directly with each other. There is no central control. Instead, individual users have control over whether they share their files and printers. Each user has responsibility for their own anti-virus updates and back-ups. There is usually one username/password for the whole network. It is suitable for home use or a small area with few users. More than 15 users and the network becomes congested.
State 3 benefits of a peer-to-peer network
Cheap option, less equipment - no server needed
Lower software license fees - no network OS or management applications needed
Low/no operating costs - no network manager staff needed
Peer control - each user decides what resources to share
No single point of failure as there is no central server.
State 3 disadvantages of a peer-to-peer network
Any security weakness puts all PCs at risk
Each user needs to perform their own back-ups
Searching through another user’s files and folders is frustrating…
Only one level of security access. A user with a password has access to everything.
Suited to small number of users because it is too difficult to coordinate updates and settings on lots of different machines
More than 15 users and the network becomes congested.
Define a client-server network
Central server(s) provide shared resources to client computers. Files and software applications are stored centrally on the server(s). It is hierarchical - clients depend on the server(s). User accounts, anti-virus and application upgrades are all coordinated centrally. Users have different levels of access (hierarchy of passwords), so sensitive data is protected.
State 3 benefits of client-server networks
Suited for large or small networks
End users don’t need technical knowledge - the network manager handles everything
Security is managed centrally, so is under the control of a specialised team
Files and applications are easier to find than with peer-to-peer
Users have a common interface and can sign in from any computer on the network.
Software licenses and updates and back-ups are managed centrally. The user doesn’t need to do it.
State 3 disadvantages of a client-server network
More expensive than peer-to-peer - need server hardware and a licence for the operating system
Maintenance costs - skilled network manager personnel are needed
More network bandwidth needed to handle traffic to and from the server(s)
If the server goes down all the clients are affected
A network operating system is needed, such as Windows Server or Linux. This adds complexity.
State 5 tasks a Network Administrator can do remotely
Ensure software and security patches are always updated
Keep software licences up to date (fees should be paid)
Use tools to take control of a user’s computer and guide them through technical problems
Prevent downloads of unauthorised software
Monitor individuals’ use of ICT resources, such as network bandwidth
Monitor performance of ICT resources - computers, applications, network, printers… etc.
Monitor CPU performance and disc use of individual computers
Clear printer queues
Log users off automatically when a PC is not in use
Shut down equipment or PCs that are broken
Rebuild and reconfigure software
In what 4 ways can a network administrator protect the company’s data and ICT resources from attack?
Require employees to enter a username & password
Install virus checking software
Implement firewalls between external and internal networks
Encrypt sensitive data as it passes over the network
Back up all data regularly
State 2 characteristics of a ring network topology.
All network nodes are connected in a circle
Data sent by one computer passes around the ring until it reaches the destination computer
The network is not dependant on any single computer
Each computer has equal access to resources, so one user can’t hog all the bandwidth
State 2 characteristics of a bus network topology.
All nodes are linked via a common shared connection called the backbone.
Signals pass in either direction.
The backbone has a terminator at each end.
State 3 characteristics of a star network topology.
Computers are connected to a central network node. The node is usually a switch.
Star is the most common topology in company LANs (Local Area Networks).
State 2 advantages of a ring network topology.
The network is not dependent on a central node
All computers have the same access to the network, so no one computer hogs the bandwidth
One computer sends at one time, which avoids data collisions so large files can transfer quickly
State 2 disadvantages of a ring network.
If there is a break in the cable connection the entire network may fail
Faults are difficult to locate
The network needs to be stopped while new computers are added
State an advantage of a bus network.
Cost saving as fewer cable runs are needed.
You don’t need to disconnect other computers to add new ones to the network (extensable).
