6 Network Infrastructure

This chapter provides contextual information that supplements information in Oracle Networking Expectations.

Network infrastructure refers to the resources that make network or internet connectivity, management, business operations, and communication possible. Its components include hardware and software systems that manage communication between users, services, applications, and processes.

The primary components of a network can be divided into three categories:
  1. Hardware: Cables, LAN cards, switches, routers, wireless routers, and other physical devices.
  2. Software: Network security applications, firewalls, operating systems, network management tools, network operations software, and more.
  3. Services: IP addressing, load balancing, security protocols, wireless protocols, and LAN service protocols such as VLAN, VPN, and Spanning Tree Protocol, among others.

For hardware, software, and services to function together seamlessly, standardized processes are required. These standards ensure that any network component can operate regardless of its manufacturer. Hardware, applications, services, and protocols should all interoperate. The Open Systems Interconnection (OSI) Model, developed by the International Organization for Standardization (ISO), provides a common reference framework for all parts of a network.

The OSI Model has seven layers which are described in the following table.

Table 6-1 OSI Model Layers

Layer Number Description

Layer 7 (Application)

This is the layer where most user interactions take place. Web browsers and other internet-connected applications, such as Outlook, utilize Layer 7 application protocols.

Examples: SNMP, HTTP, FTP

Layer 6 (Presentation)

This layer converts data to and from the application layer by translating application-specific formatting into network formatting and vice versa. This process ensures that different layers can understand and communicate with each other.

Examples: encryption, ASCII, PNG, MIDI

Layer5 (Session)

This layer establishes and terminates connections between devices. It also manages which packets are associated with specific text and image files.

Examples: Syn/Ack, NetBIOS

Layer4 (Transport)

This layer coordinates data transfer between systems and hosts, including error checking and data recovery.

Examples: TCP, UDP, port numbers

Layer 3 (Network)

This layer determines how data is sent to the receiving device. It is responsible for packet forwarding, routing, and addressing.

Examples: IP, Routers, Ethernet, Wi-Fi

Layer 2 (Data Link)

This layer translates binary data (bits) into signals and enables the upper layers to access the physical transmission media.

Examples: MAC, Switches, Fiber Optic

Layer 1 (Physical)

The actual hardware resides at this layer. It transmits signals over the physical media.

Examples: cable, RJ45

Benefits of Planned Network Infrastructure

Scalability: A robust network infrastructure allows your business to grow without the need to redesign the entire network.

Cost-effectiveness: A well-designed infrastructure reduces network disruptions, helping to lower overall costs.

Security: Managed network services offer enhanced protection against threats such as spam, malware, and viruses, while also keeping your data safe and secure.

Efficiency: Building a secure network infrastructure minimizes downtime and helps maintain consistent productivity.

Location: Network infrastructure allows sites to connect to your network, regardless of their physical location.