Network Virtualization

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Network Virtualizacion

General description

Definitions

Relationship Between Data Centers And Cloud Computing

Characteristics of data Centers

Data center: A facility for data storage and processing managed by an internal IT departament of leased off-side

Cloud Conputing an off-site service providing on-demand access to a shared pool of configurable computing resourses, provisioned and released whit minimal management effort

A data center can ocupy a room a floor or an entire building

13.2 VIRTUALIZATION

13.2.1 Cloud Computing and Virtualization

Virtualization decouples the operating system (OS) from the hardware, enabling flexible resource allocation. Cloud providers like Amazon Web Services (AWS) offer dynamic server provisioning on demand. For instance, AWS allows users to easily deploy virtualized server instances as needed. Using the AWS Management Console, administrators can manage various services, including virtual machines, web applications, virtual servers, and IoT device connections.

13.2.2 Dedicated Servers

13.2.3 Server Virtualization

13.2.4 Advantages of Virtualization

13.2.5 Abstraction Layers

13.2.6 Type 2 Hypervisors

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Dedicated services are network resources and hardware specifically reserved for the use of a single customer or application, ensuring predictable performance and high reliability. Unlike shared resources, dedicated services provide greater control, security, and tailored performance metrics, making them ideal for applications with strict requirements, such as voice over IP (VoIP), video conferencing, and critical business operations.

Server virtualization is a technology that separates the physical hardware from the operating system (OS) to create multiple virtual servers on a single physical server. This is achieved using hypervisors, which manage the creation and operation of virtual machines (VMs).

Virtualization provides several key advantages. It improves resource efficiency by allowing multiple virtual machines (VMs) to operate on a single physical server, minimizing idle hardware. This leads to significant cost savings by reducing the need for physical servers, energy consumption, and maintenance efforts. Virtualization also offers scalability, enabling organizations to adjust resources quickly by adding or removing virtual machines as needed. It enhances flexibility by supporting different operating systems and applications on the same hardware.

Additionally, it simplifies disaster recovery with easy backup and restoration through VM snapshots and replication. Virtualization also supports testing and development in isolated environments, ensuring production systems remain unaffected. These benefits make virtualization essential in modern IT and cloud computing.

This module focuses on the concept of abstraction in networking and its role in simplifying complex processes. Abstraction involves breaking down a system into layers, each with specific responsibilities, to streamline communication and troubleshooting. The OSI (Open Systems Interconnection) model and TCP/IP model are key examples, organizing network functions into distinct layers

Hypervisors are critical to virtualization, enabling multiple virtual machines (VMs) to run on a single physical machine. They act as a layer between the hardware and the operating systems of the VMs, allocating resources and ensuring isolation.

Type 1 (Bare-Metal): Installed directly on the hardware, offering better performance and stability. Common in enterprise environments (e.g., VMware ESXi, Microsoft Hyper-V).

Type 2 (Hosted): Runs on top of a host operating system, suitable for personal or small-scale use (e.g., Oracle VirtualBox, VMware Workstation).

13.3 Virtual Network Infraestructure

13.3.1 Type 1 Hypervisors

the hypervisor is installed directly on the server or networking hardware. Then, instances of an OS are installed on the hypervisor, as shown in the figure. Type 1 hypervisors have direct access to the hardware resources. Therefore, they are more efficient than hosted architectures. Type 1 hypervisors improve scalability, performance, and robustness.

13.3.2 Installing a VM on a Hyperviso

When a Type 1 hypervisor is installed, and the server is rebooted, only basic information is displayed, such as the OS version, the amount of RAM, and the IP address. An OS instance cannot be created from this screen. Type 1 hypervisors require a “management console” to manage the hypervisor. Management software is used to manage multiple servers using the same hypervisor. The management console can automatically consolidate servers and power on or off servers as required.

For example, assume that Server1 in the figure becomes low on resources. To make more resources available, the network administrator uses the management console to move the Windows instance to the hypervisor on Server2. The management console can also be programmed with thresholds that will trigger the move automatically.

13.3.3 The Complexity of Network Virtualization

Network virtualization introduces complexity by abstracting physical components into virtual equivalents, requiring advanced configuration and management. Virtual networks operate on top of physical infrastructure, adding layers of abstraction and dynamic environments that adapt to application demands. This creates challenges in resource allocation, traffic management, and the coordination of interconnected hardware, software, and protocols.

Additionally, virtualization expands the attack surface, necessitating robust security strategies. Managing virtualized networks effectively requires advanced tools, automation, and expertise to ensure scalability, performance, and reliability.

  1. 4 Software-Defined Networking