Understand the network operating system

1. What is an operating system? What's the effect?

Operating System (English: Operating System, referred to as OS) is a computer program that manages and controls computer hardware and software resources. It is the most basic system software that runs directly on the "bare metal". Any other software must be supported by the operating system To run.
There are many types of operating systems. The operating systems installed on various devices can range from simple to complex, and can be divided into smart card operating systems, real-time operating systems, sensor node operating systems, embedded operating systems, personal computer operating systems, and multi-processor operations System, network operating system and mainframe operating system. [1] According to the application field, there are three main types: desktop operating system, server operating system and embedded operating system.
The main functions of the operating system are resource management, program control and human-computer interaction. The resources of a computer system can be divided into two categories: equipment resources and information resources. Device resources refer to the hardware devices that make up the computer, such as the central processing unit, main memory, disk storage, printers, tape storage, monitors, keyboard input devices, and mice. Information resources refer to various data stored in the computer, such as files, program libraries, knowledge bases, system software and application software, etc.

2. What are the common operating systems?

The so-called operating system is the management of computer hardware and software programs. All software is developed on the basis of operating system programs. In fact, there are many types of operating systems, including industrial, commercial, and personal use, covering a wide range. Here I only introduce what are the common operating systems of our computers.

windows operating system

The windows operating system is developed by Microsoft, and most of them are used in our usual desktop and laptop computers. The windows operating system has a good user interface and simple operation. We are most familiar with Windows XP and the now very popular Windows 7, as well as the relatively new Windows 8. Microsoft has also developed operating systems suitable for servers, such as windows server 2000 and windows server 2003. General desktop computers will not go. Install this kind of operating system, because the original design is for the server installation, the hardware requirements are different.

UNIX operating system

UNIX is basically installed on the server, there is no user interface, basically command operations. So when you enter the system, it is a dark interface, and then a cursor flashes. There is no entertainment software, no pictures, no music.

linux operating system

Linux is the child of UNIX. He inherited many features of UNIX and added some new functions of his own. Some linux has an interface and some do not. And Linux is open source and free. Anyone can use it to make changes, and then develop an operating system with its own characteristics. The better ones are: Red Flag, Ubuntu, Fedora, Debian, etc. These can be installed on a desktop or laptop. Corresponding software can also be used, such as: QQ, IE and other commonly used software.

Apple Operating System (Mac OS)

Apple's operating system is a relatively well-known operating system. In fact, everyone does not know that it was developed based on UNIX. He has a good user experience, gorgeous user interface and simple operation. His design is very user-friendly, and what he wants most is a good user experience.
Our common ones are the above ones. In fact, the most primitive is windows and UNIX. There are many types of operating systems derived from UNIX. Because of its security and qualitative properties, but the user experience is not good, it is generally used in industry and commerce. In fact, Android also has a computer version of the operating system, but it is still being evaluated, and I wonder if it can be promoted. Chrome OS is also the operating system of the computer.

3. What is a network operating system?

The network operating system is an operating system that realizes the management and control of network resources in a network environment, and is an interface between users and network resources. The network operating system is built on an independent operating system and provides a bridge for network users to use network system resources. When multiple users compete for system resources, the network operating system performs resource adjustment management. It relies on each independent computer operating system to manage its own resources, and coordinates and manages the interaction of network user processes or programs with the online operating system.

4. The role and function of the network operating system?

The network operation system (NOS) is the heart and soul of the network, and is a special operating system that can control and manage network resources. It is different from the general computer operating system: it works under the computer operating system, so that the computer operating system increases the capabilities required for network operations.
The network operating system mainly refers to the operating system running on various servers, currently mainly UNIX, linux, windows and Netware systems. Various operating systems have their own advantages in network applications, but actual applications are very different. This situation has prompted various operating systems to provide cross-platform application support.
In general, NOS is aimed at optimizing network-related features, such as sharing data files, software applications, and sharing hard drives, printers, modems, scanners, and fax machines. The general PC operating system, such as Mac OS X, OS/2 and Windows 9X～XP, etc., is designed to optimize the interaction between users and the system and various applications running on this operating system.

5. The history of the development of network operating systems?

The first generation network operating system-monolithic architecture

Early network operating systems were a piece of iron, and they were generally dedicated and run in a monotonous memory space, often directly read from flash memory or ROM.
  With the adoption of a cooperative multitasking mode, support for multi-process protocols, data packet processing and management, network operating systems have a great advantage: the risk of running a complete commercial operating system on embedded hardware is eliminated. But memory management, protection, and content exchange are almost non-existent. Their success and final application have turned the network into an industry, accelerating the expansion of enterprise networks by deploying network equipment.
  But the monolithic architecture also has considerable disadvantages, that is, it is difficult to handle resource management and fault isolation. This means that network or system failures will threaten the overall architecture, and it is often impossible to ensure a stable network environment. Out of huge concerns about the reliability and manageability of this structure, many companies avoid operating in the global network environment.

The second generation of network operating system-modularization of the control layer

In the 1990s, it has become a development trend to run full-scale commercial operating systems on embedded platforms, but these operating systems cannot maintain packet forwarding performance at a satisfactory speed. As a result, the concept of hard segmentation of the control platform and the forwarding platform came into being. In the era of the second-generation network operating system, a modular control layer was realized, which made up for the shortcomings of the first-generation system, and was able to maintain the packet forwarding data transmission rate at a relatively satisfactory speed.
  The second-generation network operating system clearly realized the separation of the control layer and the forwarding layer, got rid of packet switching, and focused on the control layer functions. Compared with the first generation, the second generation network operating system can make full use of its potential in multitasking, multithreading, memory management and environmental control, and greatly reduce the probability of system-wide failures.
  When the industry's first application-specific integrated circuit (ASIC)-driven routing platform-Juniper M40 succeeded, this approach began to gain widespread acceptance in the industry. Data packets are completely forwarded in silicon, which paves the way for the third-generation network operating system led by Juniper using JUNOS software. Today, although most of the original M40 routers have been retired, some of their remaining features still exist in many similar designs. Their design drawings are regarded as the second-generation reference architecture and are widely recognized by the industry.
  The second-generation network operating system is also not flawless: due to the lack of a software data layer, without a (independent) hardware forwarding layer, it cannot provide power to low-end devices; the incompatibility with old software also makes many with old network architectures Enterprises suffer from headaches.

The third generation of network operating systems-a new era of usability and flexibility

Commercial competition has increased the demand for lower operating costs. At the same time, as network complexity continues to increase, network operating systems must become operating systems in the true sense: they need to be able to support business continuity, and software failures and system upgrades caused by routing codes cannot be corrected. The system continues to operate for 24 hours.
  These requirements have contributed to the arrival of today's third-generation network operating system era. The third-generation network operating system can meet the availability requirements and support the aggregation function, which is far superior to the second-generation router with hardware redundancy. They also support the system's planned and unplanned zero downtime operation.
  Third-generation operating systems, such as Juniper’s JUNOS software, are designed to learn from the experience and lessons of previous generations of operating systems that are difficult to migrate from one system to another, making system migration easier. They provide an evolutionary, not just revolutionary upgrade path, support business flexibility and scalability, and fully meet the needs of today's enterprises. Therefore, the third-generation network operating system represented by JUNOS has achieved the dream of building a reliable and high-security network all over the world.
JUNOS operating system-a consistent operating environment
  The core advantage of JUNOS mainly comes from its composition, that is, the "power of one" claimed by Juniper:
a single operating system, deployed on all types and scales of platforms, reducing planning , Time and effort to deploy and operate the network and security infrastructure.
A single version series, with a stable, time-tested rhythm to stably provide a new feature set.
A single modular architecture provides highly available and scalable software to meet the ever-changing needs of users.
  Some manufacturers hope to build different operating systems based on different devices and functions, and some manufacturers try to update design drawings and patches, but Juniper Networks has always upheld its promise and is committed to providing users with a single operating system. This unique and comprehensive third-generation operating system construction method differentiates Juniper Networks from many competitors.
to sum up
  In general, network operating systems have gone through three generations of development. Each generation of operating systems has completely different architecture and design goals, but like many information technologies, they are born out of demand and develop in compliance with the market.

6. What are the common network operating system systems?

Network operating systemsCurrently, there are mainly the following types of network operating systems in local area networks:

1. Windows class

I believe that anyone who has used a computer will not be unfamiliar with this type of operating system, which is developed by the world's largest software developer-Microsoft. Microsoft's Windows system not only occupies an absolute advantage in personal operating systems, it also has a very strong force in network operating systems. This type of operating system configuration is the most common in the entire LAN configuration, but because it requires high server hardware and not very stable performance, Microsoft's network operating system is generally only used in low-end servers, high-end servers Non-Windows operating systems such as UNIX, LINUX or Solairs are usually used. In the local area network, Microsoft's network operating systems mainly include: Windows NT 4.0 Serve, Windows 2000 Server/Advance Server, and the latest Windows 2003 Server/Advance
Server, etc. The workstation system can use any Windows or non-Windows operating system, including personal Operating system, such as Windows 9x/ME/XP, etc.
In the entire Windows network operating system, the most successful system is to forget the Windows NT4.0 system, which has almost become the standard operating system for small and medium-sized enterprise LANs. One is that it inherits the unified interface of the Windows family and enables users to It is easier to learn and use. Moreover, its functions are indeed relatively powerful, and can basically meet the various network requirements of all small and medium-sized enterprises. Although it is much inferior in function compared to Windows 2000/2003 Server system, it has much lower hardware configuration requirements for the server, which can meet the PC server configuration requirements of many small and medium-sized enterprises to a greater extent.

2. NetWare category

Although the NetWare operating system is not as good as it was in the early years, it has long lost its dominance in the local area network, but the NetWare operating system still has relatively low requirements for network hardware (workstations only need 286 computers). Small and medium-sized enterprises with relatively backward equipment, especially schools, are favored. People can't forget its advantages in the construction of diskless workstations for a while, and can't forget its generosity without excessive demand. And because it is compatible with DOS commands, its application environment is similar to DOS. After a long period of development, it has a wealth of application software support, and its technology is complete and reliable. At present, the commonly used versions are 3.11, 3.12 and 4.10, V4.11, V5.0 and other Chinese and English versions. NetWare servers have better support for diskless stations and games, and are often used in teaching networks and game halls. At present, the market share of this operating system is showing a downward trend, and this part of the market is mainly divided up by the Windows NT/2000Linux system.

3.Unix system

At present, the commonly used UNIX system versions mainly include: Unix SUR4.0, HP-UX 11.0, SUN's Solaris8.0, etc. Support network file system services, provide data and other applications, powerful functions,
launched by AT&T . This kind of network operating system is stable and has very good security performance, but because it is mostly
operated in command mode with SCO , it is not easy to master, especially for beginners. Because of this, small local area networks basically do not use Unix as a network operating system. UNIX is generally used in large-scale websites or large-scale enterprise and enterprise LANs. The UNIX network operating system has a long history, and its good network management functions have been accepted by the majority of network users, and it has a wealth of application software support. The current versions of the UNIX network operating system include: AT&T and SCO's UNIXSVR3.2, SVR4.0, and SVR4.2. UNIX is an operating system developed for the environment of a minicomputer host. It is a centralized time-sharing multi-user architecture. Because its system structure can be reasonable, the market share of UNIX shows a downward trend.

4.Linux

This is a new type of network operating system. Its biggest feature is that the source code is open and many applications can be obtained for free. There are also Chinese versions of Linux, such as REDHAT (Red Hat), Red Flag Linux, etc. It has been fully affirmed by users in China, which is mainly reflected in its security and stability. It has many similarities with Unix. But at present, this type of operating system is still mainly used in medium and high-end servers.
In general, the support for a specific computing environment makes each operating system suitable for its own work environment. This is the system's support for a specific computing environment. For example, Windows 2000 Professional is suitable for desktop computers, Linux is currently more suitable for small networks, and Windows 2000 Server and UNIX are suitable for large server applications. Therefore, for different network applications, we need to choose a suitable network operating system purposefully.

7. What is the difference between a network operating system and a normal operating system?

Introduction to Network Operating System

NOS differs from single-user operating systems or multi-user operating systems running on workstations due to the different types of services provided. Under normal circumstances, NOS is aimed at optimizing network-related features, such as sharing data files, software applications, and sharing hard drives, printers, modems, scanners, and fax machines. General computer operating systems, such as DOS and OS/2, are designed to optimize the interaction between users and the system and various applications running on this operating system.
In order to prevent more than one user from accessing files at a time, general network operating systems have file locking functions. If the system does not have this function, the user will not work normally. The file lock function keeps track of every file in use and ensures that only one user can edit it at a time. The file can also be locked by the user's password to maintain the specificity of the special file.
NOS is also responsible for managing the connection between LAN users and LAN printers. NOS always keeps track of every available printer and every user's print request, and manages how to satisfy these requests, so that each end user feels that the printer operating is directly connected to its computer.
The network operating system is different from the single-user operating system (such as WINDOWS98, etc.) or multi-user operating system running on the workstation due to the different types of services provided. In general, network operating systems are designed to optimize network-related characteristics. Such as sharing data files, software applications, and sharing hard drives, printers, modems, scanners, and fax machines. General computer operating systems, such as DOS and OS/2, are designed to optimize the interaction between users and the system and various applications running on this operating system.
The difference between the two lies in the difference in the services they provide. The network operating system (nos) focuses on optimizing the characteristics related to network activities, that is, to manage such as shared data files through the network, and software applications brown external devices. The os is focused on optimizing the interface between the user and the system and the applications running on it. The
operating system is based on the BIOS and is a set of software used to run application software. It mobilizes the functions of the hardware and The code of the application software is translated and run, and other software issues orders to the computer through it.