Network Architecture

Network architecture refers to the way network devices, such as routers, firewalls, switches, etc, and network services such as DNS, DHCP, email systems, etc, are designed to serve the connectivity requirements of client devices and applications in an organization. Besides, the design of network architecture involves optimizing its building blocks such as transmission media, hardware, protocols and topology. Clients devices that access the network architecture consists of end-user devices, workstations, servers and smart devices such as smartphones, IP TV, tablets, and related servers. Moreover, network architectures are developed to serve the needs of the clients.

Network topologies, protocols and models are the foundational concepts to design secure network architectures. Furthermore, the most common types of network include local area network (LAN), metropolitan area network (MAN), wide area network (WAN), personal area network (PAN), Internet, Extranet and Intranet to name a few. Besides to these key components and concepts, there are two fundamental security principles that directly affect the design of network architecture for a given organization. These principles are layering and separation of domain (Segmentation).

• Layering: Layering is very crucial principle of network architecture and involves designing the architecture using multiple security mechanisms or controls in series or defense-in-depth manner. It is important because no single control can protect against all potential security threats. Therefore, using a multilayered approach allows numerous different security controls to protect against whatever security threats try to circumvent the network.
• Domain Separation: Domain separation is an architectural principle that organizations apply to design secure network architecture. It involves separating network traffic at the collision domain and helps to avoid network traffic congestion. Besides, it involves segmenting network traffic into broadcast domains to further stop an adversary from sniffing valuable information to the overall network topology. In addition, separating a network into segments separates local network from travelling across routes.

There are different network architectures that organizations build to server their business requirements. Some of the common network architectures include the following:

• Access networks: build campus and branch networks that enable employees and devices to connect with an office building
• Datacenter networks: Connect servers that host data, systems and applications, and make them available to users
• Wide Area Networks (WAN): Connect users to applications and systems over a long haul transmissions

The following are some of the core ingredients of network architecture:

• Scalability
• Fault-tolerance
• Quality of service (QoS)
• Security