Скачать или смотреть Domain 02 - Telecommunication and Network Security Part 3

This domain covers the fundamental structures, transmission methods, transport formats, and security measures used to provide integrity, availability, authentication, and confidentiality in information transfers across networks and telecommunication systems. It provides a deep understanding of the critical elements that enable secure communications and forms an essential part of any cybersecurity professional’s knowledge.

This video begins by addressing how networking is foundational to all technology, given the evolution of mobile phones, tablets, cloud computing, and the Internet of Things. All these depend on secure, reliable networking to function. At the heart of this discussion are the OSI and TCP/IP models. The video explains each of the seven layers of the OSI model and how it differs from and relates to the simplified four-layer TCP/IP model. It highlights where protocols such as TCP, IP, and ICMP operate within these models.

A significant portion of this video breaks down network topologies. It covers bus, tree, ring, mesh, and star configurations, explaining their respective advantages and limitations. It also introduces the concepts of local area networks (LAN), wide area networks (WAN), campus area networks (CAN), metropolitan area networks (MAN), and personal area networks (PAN), and provides examples of where each might be used in practice.

The physical layer and different transmission types are covered in detail. These include both digital and analogue communication, transmission multiplexing, and the properties of shielded and unshielded twisted pair cables, fibre optics, and wireless technologies such as microwave transmission and spread spectrum techniques. The differences between frequency-hopping spread spectrum and direct-sequence spread spectrum are clearly explained.

This video also delves into the critical role of network devices. These include modems, network interface cards (NICs), multiplexers, hubs, repeaters, bridges, switches, routers, and gateways. The placement of these devices within the OSI model is discussed, alongside their core functionalities. The discussion then shifts to devices that enable access and secure communication such as remote access servers (RAS), network access servers (NAS), virtual private networks (VPNs), bastion hosts, and firewalls.

In terms of remote access and authentication, the video walks through a range of protocols and methods. It explains point-to-point protocol (PPP), password authentication protocol (PAP), challenge handshake authentication protocol (CHAP), and extensible authentication protocol (EAP). You will gain clarity on the use of centralised authentication methods such as RADIUS and TACACS+, and how these protocols differ in their implementation and security capabilities.

Securing communications is essential. The video explores the use of encryption protocols, focusing on IPsec, SSL, and TLS. It details the operation of IPsec in transport and tunnel modes and discusses encapsulating security payload (ESP) and authentication header (AH) mechanisms. Common tunnelling protocols like PPTP, L2TP, and GRE are introduced, alongside multiprotocol label switching (MPLS) and the differences between VPN protocols in various OSI layers.

The network security section introduces the importance of segmentation and access control. It covers subnetting, VLANs, NAT, firewalls, and intrusion detection and prevention systems (IDS and IPS). Firewalls are explored in terms of their filtering techniques: packet-filtering, stateful inspection, and application-layer proxy. It also discusses different deployment options such as screened hosts and screened subnet architectures.

The video further investigates threats and attacks on networks. It includes a thorough review of reconnaissance methods like footprinting and port analysis. Techniques such as privilege escalation, DNS poisoning, ARP cache poisoning, MAC flooding, and man-in-the-middle attacks are defined and paired with countermeasures. It also covers denial-of-service and distributed denial-of-service attacks, and how these are orchestrated and mitigated.

The topic of cloud security is introduced through key concepts such as multitenancy, elasticity, resiliency, and regulatory compliance. Cloud service models—Infrastructure as a Service (IaaS), Platform as a Service (PaaS), Software as a Service (SaaS), Network as a Service (NaaS), and Database as a Service (DBaaS)—are covered alongside deployment models such as public, private, community, hybrid, and personal clouds. Security challenges in cloud environments are highlighted, with emphasis on identity management, virtualisation, APIs, and storage security.

Finally, the video discusses converged protocols and technologies. It explains Fibre Channel, iSCSI, VoIP, and convergence issues like jitter, latency, packet loss, and Real-time Transport Protocol (RTP).