Networking and Hosting Flashcards
What is a network packet?
Formatted unit of data carried by a packet-switched network.
It consists of control information and user data.
What does a hub do?
Broadcasts to all ports at the physical layer.
What does a switch do?
Knows which port to send the message to working at the data link layer and sometimes the network layer.
What does a router do?
Routes packets until they reach their destination.
What is the difference between bridging and routing?
Bridging passes all network traffic whereas routing only handles “directed” traffic.
Name 5 network topologies.
Bus Ring Star Tree Mesh
What does a routing table determine?
The forwarding or next-hop IP address.
The interface to be used for the forwarding.
What do you need to be aware of when connecting to a medical network?
Firewalls.
Only allowing predefined IP addresses through.
Port numbers.
The direction the message is travelling in.
Whether the incoming message is a reponse to an outgoing one (e.g. a web page).
Specific exceptions to the rule.
Packet filtering - the header of the packet is examined in order to extract the information required for the rules.
What is the OSI 7-layer model?
Physical Data link Network Transport Session Presentation Application
What is the physical layer in the OSI 7-layer model?
It is concerned with the transmission and reception of unstructured raw bit steam over a physical medium.
What does the data link layer in the OSI 7-layer model do?
Provides error-free transfer of data frames from one node to another over the physical layer.
What does the network layer in the OSI 7-layer model do?
Controls the operation of the subnet, deciding which physical path the data should take.
What does the transport layer in the OSI 7-layer model do?
Ensures messages are delivered error-free.
What does the session layer in the OSI 7-layer model do?
Establishes a session between processes running on different stations.
What does the presentation layer in the OSI 7-layer model do?
Formats the data to be presented to the application layer. It can be viewed as the translator for the network.
What does the application layer in the OSI 7-layer model do?
Serves as the window for users and application processes to access network services.
What is a packet?
Refers to a data unit at the network layer.
What are the benefits of cloud computing?
System prototyping and evaluation. Reduction of costs. Flexibility. Universal access. Up to date software. Choice of software. Potential to be greener and more economical.
What are the advantages of virtualisation?
Lower power consumption. Less cooling required. Less rack space. Centralised administration. Quick and efficient (just copy another virtual machine). Easier backup and disaster recovery.
What is a public cloud?
A service provider makes resources, such as application and storage, available to the general public over the Internet. They may be free or offered on a pay-per-usage model.
What is a private cloud?
A type of cloud computing that delivers similar advantages to public cloud, including scalability and self-service, but through proprietary architecture. Unlike public clouds, which deliver services to multiple organisations, a private cloud is dedicated to a single organisation.
What is a hybrid cloud?
A cloud computing environment which uses a mix of on-premises, private cloud and third-party, public cloud services with orchestration between the two platforms. By allowing workloads to move between private and public clouds as computing needs and costs change, hybrid clouds give businesses greater flexibility and more fata deployment methods.
Privacy and security issues in Web applications?
Internal procedures or staff are often a reason for data leakage.
- Poor access management.
- Lack of awareness.
- Weak anonymization of personal data.
Automatic session timeout and a highly visible logout button is security state-of-the-art.
What is metadata in DICOM?
The supporting details allowing meaningful clinical use of an image.
