This website houses notes from my studies at the University of Liverpool. If you see any errors or issues, please do open an issue on this site's GitHub.
Delay There are several types of delay that a packet can experience: Nodal Processing ($d_\text{proc}$) Checking for bit errors. Determining the output link. Generally < 1 ms Queuing Delay Time waiting at output link for transmission. Depends on the congestion level of the router. Transmission Delay \[d_\text{trans}=\frac L R\] $L$...
Queries are not covered in this lecture and will have their own notes. Insert For the following table: name number programme Anna 20171989 G402 John 20174378 G702 If you want to insert a value you would use the following command: INSERT INTO Students VALUES('Oliver', 20171112, 'G402'); ' is used to...
Requirements Engineering & Specification Software specification is the process of establishing what services are requires and the constraints on the system’s operation and development. Requirements Engineering Process flowchart LR fs([Feasibility Study]) --> re([Requirements Elicitation & Analysis]) <--> rs([Requirements Specification]) <--> rv([Requirements Validation]) fs --> fr[Feasibility Report] re --> sm[System Models]...
Here is an example of a finite automaton: stateDiagram-v2 direction LR [*] --> 0p 5p --> go: +10 0p --> 5p: +5 5p --> 10p: +5 10p --> go: +5, +10 go --> 0p: R 0p --> 0p: R 0p --> 10p: +10 5p --> 5p: R 10p --> 10p:...
The network core is a mesh of interconnected routers. They use packet-switching to break the application-layer messages into packets: Forward packets from one router to the next, across links on path from the source to the destination. Each packet is transmitted at full link capacity. Store and Forward The entire...
This covers how to: Create Alter Delete databases, tables and their attributes. Create a Database Databases are similar to a folder and are initially empty. They can be filled with tables. CREATE DATABASE databasename; The commands in SQL are not case-sensitive. Conventionally, they are in upper-case. Creating Tables CREATE TABLE...
When you are completing a process you need to separate the process into individual tasks. These tasks can include planning, execution, testing and review. A process is a sequence of steps to accomplish a set of tasks. Characteristics Any process has the following characteristics: It prescribes all of the major...
Set Theory Recap $\emptyset \{\emptyset\}$ The empty set or a set containing the empty set. $\{a_1,a_2,\ldots,a_n\}$ This is a set. $a\in A,B\subseteq A$ $a$ in in $A$ and $B$ is a subset of $A$. $A\cup B,A\cap B,A\backslash B$ Sum, intersection and difference. $2^A=\{B\vert B\subseteq A \}=\{B:B\subseteq A\}$ Denotes all the...
The main points of study in this module are: Finite Automata: Related to regex. Grammars: Extracting the meaning from a program. Turing Machines: The general model of computing. Some Kinds of Machines Type Description Finite Automata Devices with a small amount of memory. Used to model very simple things. Push-down...
The network edge is made up of the following devices: Hosts - Clients and servers. Servers - Often in data centres. The hosts are connected to the internet via access networks through physical media: Wired links Wireless links. The hosts are then connected to the network core which are a...