Network Topologies – Protocols and Layers

The first video examines the topology of modern networks – how the computers are arranged and connected together.  The history of network topologies is outlined briefly, before considering star networks in more detail.  The need for, and the advantages of a central switch, together with the concept of mesh and partial mesh networks is explored.

The second video explores a popular alternative to a wired network: WiFi.  The advantages of wireless networks are considered before looking at the concept of frequencies and channels.  Unlike wired connections, wireless devices broadcast data, and therefore there is a greater risk to the security of data.  Encryption as a solution is introduced. 

Ethernet is the most widely installed local area network (LAN) technology. It is a standard collection of related protocols and hardware, describing how networked devices can format and transmit data to other devices on the same local area network.  The third video explores all the components of Ethernet, including the concept of frames, switching and media at a level suitable for GCSE.

The fourth video takes a deeper look at the concept of addressing and protocols, following the videos on network topologies, WiFi and Ethernet.  TCP/IP for routing and error checking primarily on wide area networks is considered, together with HTTP and HTTPS as protocols for the transfer of web pages.  FTP as a protocol for the transfer of files, and the popular email protocols are also outlined: POP, IMAP and SMTP.

Networking is a complex process with many devices, services and protocols.  The concept of layers is to break the problem down into smaller sub-problems so that devices and protocols can focus on achieving just one aspect of networking.  For example, IP routes packets but does not check them for errors, that is the role of TCP.  The fifth video explores the concept of layering protocols.

Packet switching is a transmission process for wide area networks.  Data is broken up into smaller packets for fast, efficient and secure transfer.  Following the videos on mesh networks, and the concept of IP addressing, the sixth video explores in more detail how the the TCP and IP protocols enable the internet to work.

Resources:

https://student.craigndave.org/videos/ocr-gcse-slr1-5-star-and-mesh-network-topologies

https://student.craigndave.org/videos/ocr-gcse-slr1-5-wifi

https://student.craigndave.org/videos/ocr-gcse-slr1-5-ethernet

https://student.craigndave.org/videos/ocr-gcse-slr1-5-the-uses-of-ip-mac-addressing-and-protocols

https://student.craigndave.org/videos/ocr-gcse-slr1-5-the-concept-of-layers

https://student.craigndave.org/videos/ocr-gcse-slr1-5-packet-switching