Cisco IOS Internet Operating system

Cisco's Internet Operating system (IOS) is a complex operating system optimized for interconnection-similar to a local-area operating system (NOS), such as Novell's NetWare, for LANs. iOS provides a uniform rule for a long period of time to maintain an Internet economy effectively. In short, it is a hardware-separated software architecture that can be dynamically upgraded to adapt to changing technologies (hardware and software) as network technology continues to evolve. iOS can be viewed as an Internet hub: A highly intelligent administrator who manages the ability to control complex distributed network resources.

Two, the advantages of iOS features

iOS is the initial brand name for Cisco routing software. With the development of Cisco Technology, iOS is expanding to become "a series of tightly connected interconnection software products" that Cisco Central ENgineering (Center Engineering Department) calls it. Although iOS may still be synonymous with routing software in its brand name identification, its continued development has enabled it to transition to support for LAN and ATM switches and to provide important proxy capabilities for network management applications. It must be emphasized that iOS is a technology developed by Cisco: an enterprise asset. It provides the company with a unique market competitive advantage. At present, many competitors allow iOS in its hub and in the module from the operation, iOS has been widely used in internet interconnection software industry standards.

Flexibility based on Cisco product Engineering development allows users to gain flexibility to adapt to change. iOS software provides an extensible platform for Cisco to integrate new features with the development of requirements and technology. Cisco can put new products to market faster, and our customers can enjoy this advantage.

Scalable iOS is spread across the internet market; a wide range of Cisco use Partners and competitors support iOS on their products. The iOS software architecture also allows it to integrate all parts of the corporate Internet. Cisco has defined 4:

CORE/hub: Network hub and WAN services, including large backbone network routers and ATM switches.

Workgroup: from shared LAN porting to LAN switching (VLANS) provides better network segmentation and performance. ）

Remote access: A remote LAN connectivity solution, a marginal router, a modem, and so on.

IBM Internet Interconnection: SNA and LAN parallel Integration, transition from SNA to IP.

Cisco's iOS extends all of these areas and provides the robustness to support End-to-end internetwork connectivity.

Operable iOS offers the broadest range of standards-based physical and logical protocol interfaces-beyond any other vendor in the industry: from twisted pair to fiber, from LAN to Park to Wan, Novell Netware,unix,sna, and many other interfaces. That is to say, a network built around iOS will support a very wide range of applications. Also, Cisco has been an industry standard pioneer and an active member and supporter of many well-known industry standard institutions such as IETF, ATM forums, etc.



Manageability iOS is Cisco will embed intelligent embedded network devices: management interface, such as the iOS diagnostics interface, as well as intelligent network applications of proxy software, allowing for pro-vision and extensive network equipment failures. As Cisco turns to smart proxies and a massive deployment of policy-based automated management, iOS will be a key technology component.

Investment protection (and reduced cost of ownership over time) iOS provides customers with investment protection for their information infrastructure. Many of the features that iOS supports today are features that most customers will need in the future. As a company grows into new territory, the architecture provided by iOS allows the organization to flexibly apply change and expand economically and efficiently to meet new requirements as infrastructure complexity as a result of mergers and acquisitions and the advent of protocol conversions or new traffic patterns emerge. iOS allows our customers to quickly adjust to new patterns and maintain their information infrastructure investments for longer periods of time, with the result of providing investment protection and lower cost of ownership over the years.

Third, the history of iOS development

Modular to multi-connection subsystem integration

The following figure describes the evolution of iOS from a unified operating system to the current highly modular operating system.



Unity of

An earlier version of iOS was a stand-alone system, essentially a router-centric one. It is arranged into a process (Procedure) set that allows any process to call each other. This single structure makes the data less subtle and independent; most of its operational code has a correlation of structure and operation.

of modular

iOS releases 9.21 through 11.2 reflects the effort to redesign iOS into modular components or subsystems. Each subsystem is organized into a layer set (set of layers) that provides an independent entry point into the system code. The subsystem itself is defined as an independent module that supports the various functions of the embedded (core) system. This tiered subsystem design allows engineers to divide iOS into a set of features that are more manageable and easier to upgrade.

Ultimate goal

The development of iOS to portability shows that iOS 11.3 and later are easier to migrate to new platforms.

Bulleproofing

The ultimate goal is to develop iOS into a more advanced, static, modular structure that allows for a separate definition of the iOS feature that is unrelated to other features (or subsystems). Cisco can build iOS feature/solution set based on customer's specific needs. As iOS continues to develop, customers will be able to match specific iOS features to meet their particular environment requirements.

Modular to multi-link subsystem integration