This page states some of the assumed knowledge for readers of the NOC wiki.

Creating a new page for each background concept would excessively increase the number of pages in the wiki. Instead, background concepts can be grouped on pages for the courses in which those concepts would usually be taught. Use UNSW courses as a guide as to which concepts should be grouped together.

Network technologiesEdit

e.g. courses that use textbooks by Tanenbaum & Wetherall, Kurose & Ross, or Peterson & Davie, e.g. UNSW TELE3118

Protocols are listed in the layer that they usually control, rather than the layer in which they operate. eg. DHCP and routing protocols control network layer IP addresses and paths, so are listed as part of the network layer, even if they are usually implemented as application layer protocols that operate over a transport protocol such as TCP or UDP.

Topics that span layersEdit

Network layering: Physical Layer, Link Layer, Network Layer, Transport Layer, Application Layer, OSI Reference Model

protocol, PDU, packet, frame , segment, fragmentation and reassembly

demultiplexing identifiers, Ethertype, IP protocol, port number, PDU, segmentation and reassembly, header decoding


An octet is a unit of digital information in computing and telecommunications that consists of eight bits. The term is often used when the term byte might be ambigous, as there is no standard for the size of the byte

Standards? e.g. backwards compatibility

Network standards organisations: IEEE 802, IETF Requests For Comments (RFCs), OSI, ITU

IETF: The Internet Eginneering Task Force (IETF) develops and promotes Internet standards, cooperating closely with the W3C and ISO/IEC standards bodies and dealing in particular with standards of the Internet protocol suite. It is an open standards organization, with no formal membership or membership requirements.[1]

Network devices: host, interface - IP, interface - network interface card?, links, routers, switches, hub, server

topology of a network

Equipment manufacturers: Cisco, HP, Huawei

Addressing, e.g. Link-Local addresses, MAC addresses, IP addresses, unicast, broadcast, multicast

error control coding / Hamming distance / ARQ / retransmission / acknowledgements

Physical layerEdit

cables - UTP Physics:

impedance mismatch, change of refractive index


Link layerEdit

Medium Access Control (MAC)

MAC protocols: Ethernet, Token ring;

Ethernet: frame length requirements, preamble, SFD, CRC

bridges/switches Spanning Tree Protocol

packet capture / promiscuous mode Local network monitoring (sniffing)&nbsp As opposed to Remote Network Monitoring e.g. by using Wiresharkor packet capture libraries Further reading In Wikipedia: Packet capture Packet analyzer Wireshark


Address Resolution Protocol ARP ARP

Network layerEdit


Internet Protocol, IPv4, IPv6, TTL


duplicate IP addresses

Link-local Address A link-local address is an Internet Protocol address that is intended only for communications within the segment of a local network (a link) or a point-to-point connection that a host is connected to. Routers do not forward packets with link-local addresses.   routing protocols, Link-State routing, Distance-Vector routing

source routing




Dynamic Host Configuration Protocol (DHCP)

Autonomous System

Transport layerEdit


[In Australian network management, TCP also refers to Telecommunications Consumer Protection for which a code of conduct was issued in 2008 and revised before being issued in 2012 ]


Sockets programming APIEdit


Application layerEdit

Domain Name System (DNS)


web browser

Network securityEdit

e.g. UNSW TELE3119
Not assumed, but would enhance understanding of some aspects of this course

Transport Layer Security

cryptography / encryption

key - cryptographic

Denial Of Service (DOS) attacks




coldStart, warmStart

durable and volatile memory

2s-complement arithmetic

NULL termination of strings

e.g. data types, e.g. signed and unsigned integers, enumerated types

interrupts vs polling

mutual exclusion - concurrency - threads etc - atomic operations


Matrix manipulation


reliability: MTTF etc




IP Address , Subnet Mask , RFC

Routing metrics definition

Link-state routingdistance-vector routing

Address Resolution Protocol(ARP) is a telecommunications protocol used for resolution of network layer addresses into link layer addresses, a critical function in multiple-access networks. Address Resolution Protocol (ARP) exists solely to glue together the IP and Ethernet networking layers. Since networking hardware such as switches, hubs, and bridges operate on Ethernet frames, they are unaware of the higher layer data carried by these frames . Similarly, IP layer devices, operating on IP packets need to be able to transmit their IP data on Ethernets. ARP defines the conversation by which IP capable hosts can exchange mappings of their Ethernet and IP addressing.