Networking Systems Flashcards
1
Q
Name 3 common types of clinical ICT system in medical physics
A
Patient Records
Radiology Systems
Modality Systems
2
Q
Name 3 types of patient record ICT systems
A
Electronic Health Records (EHR)
Master Patient Index (MPI)
Patient Administration System (PAS)
3
Q
What are electronic health records?
A
A (supposedly) comprehensive electronic record of a patient’s entire health record, available anywhere in an organisation, the NHS, or worldwide.
4
Q
Electronic health records can be stored on either ___ or _______ servers and accessed by ____ users.
A
One
Multiple
Many
5
Q
What is the master patient index?
A
A list of all patients known to an organisation, along with their demographics and ID numbers.
6
Q
What is a patient administration system?
A
The central admin system that covers patient appointments, note tracking, etc. It often contains test results and acts as a portal to other systems.
7
Q
Name 2 types of ICT radiology systems
A
Radiology information system (RIS)
Patient archive and communications system (PACS)
8
Q
What is a radiology information system?
A
A system used for:
- Scheduling of imaging
- Resource management
- Inventory tracking
- Reporting of images
- Presentation of reports
- Report sign-off
- Billing
9
Q
What is a picture archive and communications system?
A
A system used for:
- Storage of images (‘pictures’)
- Storage of other data
- Visualisation of images
- Data transfer between systems
10
Q
What are the components of a picture archive and communications system (PACS)?
A
- Modalities
- Client applications
- Server
- Database
- Storage
11
Q
How do radiology systems interact with one another and staff?
A
12
Q
What are modality systems?
A
Any computer-controlled clinical equipment.
13
Q
How do modality data flow systems interact with one another and staff?
A
14
Q
Describe the dataflow in radiology
A
15
Q
Name 4 radiotherapy ICT systems
A
Treatment planning system
Dose checking system
Record and Verify system
Oncology management system
16
Q
What is a treatment planning system (TPS)?
A
A system used for plan preparation and dose calculation. These plans are created in either 3D or 4D.
17
Q
What is a dose checking system?
A
An independent MU check of the intended delivery for radiotherapy. This can be another TPS.
18
Q
What is a record and verify system (R&V)?
A
A system on a linac, or other treatment unit, that verifies the treatment is being delivered as intended (unless parameters out of specification have been authorised), and records the treatment actually delivered, including any unexpected deviations. It also records who authorised any intended deviations.
19
Q
What is an oncology management system (OMS)?
A
A general-purpose management system for oncology applications (radiotherapy and chemotherapy). This includes the electronic health record (EHR) and patient administration system (PAS) and may also incorporate a TPS and R&V system. It is the radiotherapy equivalent of RIS and PACS.
20
Q
What patient information is included on an oncology management system?
A
- Prescriptions
- Imaging (pre-treatment and during treatment)
- Scheduling information
- Patient documents
- General patient information
21
Q
What are the components of an oncology management system (OMS)?
A
- Client applications
- Modalities
- Server
- Database
- Storage
22
Q
Almost all clinical systems are networked (even between their own components). What are the benefits of networked systems?
A
- It allows a complex system to be made up of individual, connected components
- It allows one clinical system to communicate with another
- Multiple systems can be used in the care of a patient
23
Q
What is a logical diagram of a network?
A
A diagram that shows how different systems link to each other. It focuses on the flow of data and is generally easier to understand than a physical diagram, however, it lacks technical detail. Logical diagrams are usually produced by users of the network.
24
Q
Where are logical diagrams used?
A
- When developing new interfaces
- When mapping data flows
25
What is a physical diagram of a network?
A diagram that shows the 'Network Topology' (the arrangement of elements in a communication network). It represents physical connections between components and can be very technical, making it more difficult to understand than a logical diagram. Physical diagrams are usually maintained by the IT department.
26
What is a client/server network application?
An application in which the client software communicates with a server. Some or all of the processing is performed on the server. It uses 'thin client' technology.
27
Define thin client technology
Technology using a simple computer that has been optimised for establising a remote connection with a server-based computing environment.
28
Give an example of a client/server network application
Electronic health records (EHR)
29
What is a standalone network application?
A system that is not networked. This means that it contains all its own data and performs all its own processing.
30
Give an example of a standalone network application
A CT scanner
31
What is a hybrid network application?
A system that contains elements of both client/server and standalone applications. For example, it may acquire data from the server then perform processing locally.
32
What is a peer to peer application?
Discrete systems which communicate with each other. These can be client/server and/or standalone.
33
Give an example of a standalone and peer to peer network application
A CT scanner, PACS, and an analysis workstation.
34
What are application servers?
Extreme versions of client/server network applications. The applications are presented via a web browser and all of the processing is performed on the server.
35
What is the main benefit of an application server?
It is easy to distribute and upgrade applications without worrying about local requirements.
36
Give an example of an application server
- A PACS web viewer
- An application deployed in Citrix
37
What is the ISO OSI model of networking?
The international standards organisation open systems interconnection model. It consists of 7 layers with specific functions and responsibilities, making it easier for different devices and technologies to work together.
38
What are the 7 layers of the ISO OSI model of networking?
Application layer
Presentation layer
Session layer
Transport layer
Network layer
Data link layer
Physical layer
39
Describe the application layer in the ISO OSI model of networking
The closest layer to the user. It provides application services.
40
Describe the presentation layer in the ISO OSI model of networking
The layer that encrypts, encodes, and compresses useable data.
41
Describe the session layer in the ISO OSI model of networking
The layer that establishes, manages, and terminates sessions between end nodes.
42
Describe the transport layer in the ISO OSI model of networking
The layer that transmits data using transmission protocols, including TCP (transmission control protocol) and UDP (user datagram protocol).
43
Describe the network layer in the ISO OSI model of networking
The layer that assigns global addresses to interfaces and determines the best routes through different networks.
44
Describe the data link layer in the ISO OSI model of networking
The layer that assigns local addresses to interfaces and delivers information locally using the MAC (media access control) address.
45
Describe the physical layer in the ISO OSI model of networking
The layer that encodes signals and physically connects two devices (via cabling and connectors). In this layer, data is in the form of bits.
46
What is TCP/IP?
Transmission control protocol/internet protocol. It is a flexible model of networking with only 5 layers.
47
What are the 5 layers of TCP/IP?
Application layer
Transport layer
Internet layer
Data link layer
Physical layer
48
What is the most common IP address version?
v4
49
An IP address is a __ ___ number, usually represented by a series of _ _____.
32 bit
4 bytes
50
What is the general form of an IP address?
General form: aaa.bbb.ccc.ddd
Example: 10.1.19.246
51
How do direct connections from one IP address to another work?
The primary IP address can send information to a second specific IP address as long as they are connected, but the data cannot be transferred to any other address.
52
How do connections from one IP address to another via a hub work?
The primary IP address can send information to a hub, which will then pass the data to all connected devices, including the target IP address.
53
How do connections from one IP address to another via a switch work?
The primary IP address can send information to a switch, which only passes data onto the correct device (the target IP address).
54
How do connections from one IP address to another in a bigger network work?
The primary IP address can send information to a switch, which then passes the data to another switch connected to the correct device (the target IP address). This path between switches is known as a 'gateway'.
55
How do connections from one IP address to another in a very large network (with a router) work?
The primary IP address can send information to a switch, which passes to data to a router, then to another switch, and finally to the correct device (the target IP address).
56
What are the 4 main infrastructure components of a network?
A hub
A switch
A gateway
A router
57
What is a hub?
Network infrastructure that passes data from one IP address to all connected devices.
58
What is a switch?
Network infrastructure that passes data to only the intended device. It rejects or blocks traffic if the intended device is not connected.
59
What is a gateway?
A connection between two or more 'subnets'. This may be a switch or a router.
60
What is a router?
Network infrastructure that is dedicated to directing network traffic between physical segments of the network.
61
How can devices tell whether the destination of an IP address is on the same subnet?
A subnet is defined by a prefix or 'netmask', so the subnet address can be used to identify which subnet a device is in.
62
Can organisations use private IP addresses for a private subnet?
Yes, however, they must not appear on the internet because they are not unique.
63
What are the benefits of a private subnet?
Convenience: the IP addresses can be allocated at will.
Security: information does not appear on the internet.
64
Define Network Address Translation (NAT)
The mechanism by which traffic from a host on a private subnet can be directed to the Internet. The apparent or 'translated' address would be that of its Internet access point.
65
What is a loopback address?
A special, reserved address which directs traffic back to the local computer without reaching any 'real' network interface. It allows network services to operate without a network being present.
66
State the loopback address
127.0.0.1
67
What is the proposed replacement for IPv4?
IPv6
68
Why may IPv4 need to be replaced?
Because the number of possible addresses is running out.
69
How long is an IPv6 address?
128 bits (containing both numbers and letters)
70
What is Transmission Control Protocol (TCP)?
A way of managing data transfer as a series of bundles of information, known as 'packets'. For large data blocks, the data is divided up into smaller packets which are sent in sequential order.
71
A packet is a series of _____.
Bytes
72
How does the TCP prevent errors in data transfer?
- It has built-in error detection and correction
- Packets are acknowledged as they are received
- If a packets is lost, or found to be corrupt, it is sent again
- The data block is assembled by ordering the packets at the destination
73
Describe the structure of a TCP packet
74
What is the difference between an IP address and a port number?
An IP address is the number for a network device, and a port address is the number for an application communicating on that device (like a street address and a house number on that street).
75
Ports can be any __ ___ integer
16 bit
76
How are IP addresses and ports written together?
A port is indicated following a colon after the IP address (e.g. 10.2.17.5:104).
77
What is a universal datagram protocol (UDP)?
A way of managing data transfer using packets with a simpler structure than TCP packets. Each packet is not acknowledged before the next is sent and there is no information about a packets order in the sequence.
78
What are the advantages and disadvantages of UDP?
+ Significantly faster
- More prone to error
- Missing packets are not resent
79
Describe the structure of a UDP packet
80
What is a MAC address?
A media access control address, often referred to as a 'physical address'. It operates at the Data Link layer of the TCP/IP model and is represented by 6 bytes.
Every network interface (device) has a guaranteed, globally unique MAC address that is usually 'burned in' to the hardware. Each manufacturer has its own unique prefix for a MAC address.
81
What is a LAN?
Local area network. It is restricted to a small geographical area, like a single hospital or office building.
82
What is a WAN?
Wide area network. It is distributed over a large geographical area (e.g. the Internet). WANs can be two LANs connected together (e.g. two hospitals in the same NHS trust).
83
What is a MAN?
Metropolitan area network. It is a special care of a WAN, distributed over a city.
84
What is the health and social care network (HSCN)?
A private network linking NHS and social care organisations. Third parties can connect to the HSCN via 'connectivity suppliers'.
85
What is a directory name service (DNS)?
A network service that links hostnames to IP addresses.
86
What is a dynamic host configuration protocol (DHCP)?
A network service that allocates IP addresses automatically to a network device, based on its MAC address.
87
What is an active directory (AD)?
A network service that is a superset of the directory name service. It provides information about additional resources like user rights, printers, etc.
88
What is a VPN?
A virtual private network. They allow secure connections to networks, usually LANs, from external locations. The external resource appears on the restricted (private) network with a local IP address. To enhance security, access to local network resources si usually blocked whilst using a VPN.
89
Describe the data flow to access hospital servers using a VPN
90
What is the most common type of physical connection used in the physical layer of TCP/IP?
Ethernet cables (RJ45 cables), extended to wireless networks
91
Define network bandwidth
Also referred to as 'maximum throughput'. It is the rate at which data can be transferred in one direction. It is stated as data volume per unit time (e.g. megabits per second, Mbps).
92
How many bits are in 1 byte?
8 bits
93
How many bytes are in 1 kilobyte (1 kB)?
1024 bytes (20¹⁰ bytes)
94
How many bytes are in a megabyte (1 MB)?
1048576 bytes (20¹⁰ x 20¹⁰ bytes)
95
How many kilobytes are in a megabyte (1 MB)?
1024 kilobytes (20¹⁰ kB)
96
How many bytes are in 1 kilobit (1kb)?
128 bytes
97
How many kilobytes are in one megabit (1 Mb)?
128 kB
98
How many megabytes are in one gigabit (1 Gb)?
128 MB
99
List the commonly used volume units in computing from smallest to largest
Bit
Byte
Kilobyte (kB)
Megabyte (MB)
Gigabyte (GB)
Terabyte (TB)
Petabyte (PB)
100
How do you convert from bits to bytes?
Bytes = Bits / 8
101
How do you convert from bytes to bits?
Bits = Bytes x 8
102
Define half duplex connection
Connection where only one party can communicate at a time, analogous to using a 'walkie talkie'.
103
Define full duplex connection
Connection where both parties can communicate simultaneously.
104
How is bandwidth impacted by a half duplex connection?
Only one party can communicate at a time, so the bandwidth halves.
105
Define network latency
The delay between a packet being sent by the sender and received by the receiver. This is measured in units of time.
106
In order to troubleshoot, it is important to understand the _______, which means that you need to understand the __________.
Problem
Application
107
State 7 common troubleshooting tools
- ipconfig / ifconfig
- ping
- Trace Route
- nslookup
- netstat
- Sysinternals Tools - Procyon, tcpview
- Wireshark
108
What information about network interfaces is provided when using ipconfig?
- List of interfaces
- Status of each interface
- IP addresses
- MAC addresses
- DHCP information
- DNS information
- Other information
109
How is ping used for troubleshooting?
- It verifies that a route between a source and a destination exists
- It measures network latency
- It resolves an IP addresses from the hostname using DNS (translates a readable domain name into an IP address)
- It resolves the hostname from an IP address (translates an IP address into a readable domain name)
110
Where is ping run from when troubleshooting?
The terminal (command line)
111
How is Trace Route used for troubleshooting?
It records the routers through which packets travel on the way to their destination. It then displays ping-type statistics for each 'hop' of the journey. This is not always accurate.
112
How is nslookup used for troubleshooting?
It interrogates the DNS (directory name service) for a given hostname.
113
Where is nslookup run from when troubleshooting?
The terminal (command line)
114
How is netstat used for troubleshooting?
It reports the status and statistics of network services. It is a very flexible command. It can be used to determine whether a service is 'listening' for connections or whether a connection is in progress.
115
How are Sysinternals Tools used for troubleshooting?
They are run as GUIs and investigate specific parameters. The results from these investigations can be stored for later review.
116
How is Wireshark used for troubleshooting?
It monitors and reports on network traffic. This can either be done for the local network interface (so it reports traffic intended for the local computer) or in 'promiscuous mode' (so it reports ALL accessible network traffic). This is extremely powerful and runs as a GUI.
