Information is a strategic asset that can make or break a company's
fortunes in today's global economy. Computer internetworks are the electronic
highways upon which that information travels and they unify the world to create
new and better ways of doing business.
With so much at stake, an organization's internetwork must have the
ability to increase the overall productivity of its people and resources. To do
this, it can maximize the availability of applications while it minimizes the
total cost of ownership. This means providing users with continual access to a
flexible and reliable network. It also means keeping in check the expenses that
an organization must absorb over time in order to develop and maintain its
information systems and services.
No company in the world can match Cisco Systems when it comes to
maximizing an internetwork's applications availability and minimizing its total
cost of ownership. Over the last decade, our proven technology and wide range
of scalable solutions have enabled us to set the pace in the internetworking
industry. More than anything else, Cisco owes its leadership position to
Cisco's unique and robust Internetwork Operating System® (IOS). Cisco IOS is
value-added software that resides at the heart of all Cisco internetworking
The Cisco IOS is Cisco's key to help make information-intensive
companies all over the world more productive. And ultimately, that is the
greatest benefit that any internetwork can provide.
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This document is not restricted to specific software and hardware
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Just as a personal computer improves individual productivity, an
efficient internetwork improves the productivity of large groups of people. And
in the same way that a local area network (LAN) relies on a software-driven
network operating system (NOS) to function, an internetwork depends on a
sophisticated operating system (also implemented in software) to effectively
connect users all over the world.
An internetwork's intelligence lies in its operating system. Network
hardware inevitably changes every few years with the introduction of new
generations of processors, switching, and memory components. But the
internetwork's software is the unifying thread that connects otherwise
disparate networks and provides a scalable migration path as needs evolve.
Just as enterprises invest in LAN network operating systems that can
evolve as new hardware and applications are introduced, the Cisco IOS is a
strategic investment that enables organizations to safeguard the future of
their internetworks. Cisco IOS supports inevitable change and migration through
its ability to integrate all evolving classes of network platforms. This
includes routers, ATM switches,
LAN and WAN switches, file servers, intelligent hubs, personal computers and
any other devices that have a strategic impact on an organization's
internetwork. By powering Cisco platforms and those delivered by technology
partners who incorporate Cisco IOS into their products, Cisco IOS enables
companies to build and enhance a single, integrated, cost-effective information
Multiplatform IOS: Cisco's IOS enables an
enterprise to build an integrated, cost-effective infrastructure using
platforms from both Cisco and its partners.
Today's multifaceted enterprise internetworks typically consist of four
distinct sectors, each with its own specific mission:
of the internetwork provides broad, reliable wide-area
connections among all worldwide locations. Its focus is on cost-effective and
efficient use of expensive WAN resources.
sector provides groups of end users with scalable
bandwidth capable of meeting increasing application demands.
sector serves remote locations, telecommuters, and
mobile users with cost-effective, easily managed connectivity solutions.
The IBM internetworking sector lowers costs and
provides a safe and secure migration path for IBM SNA network applications.
The Cisco IOS spans the requirements of all these internetworking
sectors to create a single, unified infrastructure that provides lower costs,
higher applications availability, and improved internetwork management.
Enterprise Networks Today: The enterprise of
today and tomorrow has requirements that span all four internetworking sectors:
workgroup, IBM internetworking, core, and remote access.
Cisco IOS is the key differentiator that separates Cisco's
internetworking solutions from other alternatives in the industry. Its
value-added intelligence supports users and applications throughout the entire
enterprise and provides security and data integrity for the internetwork. The
IOS cost-effectively manages resources by controlling and unifying complex,
distributed network intelligence. Also, it functions as a flexible vehicle that
can add new services, features, and applications to the internetwork.
In the applications support arena, the Cisco IOS provides
interoperability with more standards-based physical and logical protocol
interfaces than any other internetwork supplier in the industry. From twisted
pair to optical fiber, LAN to campus to WAN media, UNIX to Novell NetWare to
IBM SNA, no other internetwork architecture can match the wide-ranging protocol
support of the IOS.
IOS Interfaces: Cisco's IOS supports the
industry's largest set of formal and de facto standard
The value-added intelligence of the IOS is embodied in four types of
Four IOS Cornerstones: The value-added
intelligence of the IOS is embodied in four types of services: reliable
adaptive routing, WAN optimization, management and security, and scalability
The Cisco IOS has continually set the pace in the industry for
providing innovative, robust routing intelligence. Its reliable adaptive
routing capabilities enhance productivity and applications availability by
finding performance-optimal paths and quickly routing traffic around any
network failures. Reliable adaptive routing also reduces costs by efficiently
using network bandwidth and resources while eliminating needless management of
Policy-based IOS features, such as route filtering and routing
information translatability, save network resources by preventing data from
being unnecessarily broadcast to nodes that do not require it. Priority output
queuing and custom queuing grant priority to important sessions when network
bandwidth is saturated. Load balancing makes use of all available paths across
the internetwork, preserving valuable bandwidth and improving performance. And
the IOS provides the most effective and efficient scaling available for network
applications that require transparent or source-route bridging algorithms.
Increasingly, internetworks are incorporating such new technologies as
ATM and LAN switching, which operate at Layer 2 and below of the OSI networking
model. While switching devices based on these technologies provide higher
bandwidth than existing shared-media hubs, they fail to offer the scalability,
stability, and security of their more intelligent shared-media counterparts.
Through CiscoFusion™, Cisco's scalable architecture for switched
internetworks, the IOS provides the framework for a new technology called
multilayer switching, which operates up to OSI Layer 3 or
By distributing routing intelligence and switching functions to create
"virtual LANs," CiscoFusion's multilayer switching increases bandwidth while
simplifying moves, adds, and changes across the enterprise. This extends the
power and flexibility of the IOS beyond internetwork routers to include the ATM
and LAN switches that are increasingly being deployed throughout today's
Because the large majority of network costs are expended on wide-area
network (WAN) switching and utilization functions, an effective internetwork
must optimize all WAN-related operations. Optimization promotes applications
availability by increasing network throughput while reducing delay time. It
also minimizes ownership costs by eliminating unnecessary traffic and
intelligently selecting the most economical WAN links available.
The Cisco IOS provides the highest level of WAN support in the
industry, seamlessly accommodating circuit-switched services such as ISDN,
switched T1, and dial-up telephone lines. IOS innovations such as
dial-on-demand access and dial backup capabilities provide cost-effective
alternatives to expensive point-to-point switched leased lines. And support for
advanced, packet-switched services such as X.25, Frame Relay, SMDS, and ATM
extends the internetwork across the broad range of WAN interface alternatives
The Cisco IOS provides an array of network management and security
capabilities designed to meet the needs of today's large, complex
internetworks. Integrated management simplifies administrative procedures and
shortens the time required to diagnose and fix problems. Automated operations
reduce hands-on tasks and make it possible to manage large, geographically
dispersed internetworks with a small staff of experts located at a central
The IOS provides several important management features that are built
into every Cisco router. These include configuration services that lower the
cost of installing, upgrading, and reconfiguring routers, as well as
comprehensive monitoring and diagnostic services. In addition, the IOS provides
valuable information and services to router management applications developed
by Cisco and its partners. The Cisco applications, known collectively as
CiscoWorks™, offer administrators a wide-ranging suite of operational, design,
and management capabilities that increase productivity and drive down costs.
The IOS's management services are matched by its security capabilities.
No organization today can ignore the need to protect valuable information and
applications supported on its internetwork. The Cisco IOS includes a diverse
toolkit for partitioning resources and prohibiting access to sensitive or
confidential information or processes. Multidimensional filters prevent users
from knowing that other users or resources are even on the network. Encrypted
passwords, dial-in authentication, multilevel configuration permissions, and
accounting and logging features provide protection from, and information about
unauthorized access attempts.
Scalability services provide the high degree of flexibility that is
necessary to address all of the key issues facing today's internetworks as
organizations change and their needs evolve. The IOS's scalable routing
protocols help avoid needless congestion, overcome inherent protocol
limitations, and bypass many of the obstacles that can arise because of the
scope and geographical dispersion of an internetwork. These techniques,
important in all networks, are especially essential in IBM SNA internetworking
The IOS also helps to cut costs by reducing network bandwidth and
processing overhead, offloading servers and conserving resources, and easing
system configuration tasks. Advanced IOS features such as filtering, protocol
termination and translation, smart broadcasts, and helper address services
combine to create a flexible, scalable infrastructure that can keep pace with
evolving network requirements.
Reliable adaptive routing capabilities. WAN optimization services.
Management and security features. And scalability services. These are the four
principal types of services that the IOS provides, the four cornerstones
essential to building a strategic internetwork foundation.
The IOS supports the broadest range of applications by virtue of a full
portfolio of standards-based interfaces. Thus, users with very diverse needs
and applications (from finance, to sales, to engineering) can be served by a
single, integrated network infrastructure. Wherever a user needs to be (in a
workgroup, in the data center, in a remote office, or telecommuting across a
distance) the IOS provides the network resources to increase that user's
In a world where hardware platforms are constantly evolving, software
intelligence is the value-added differentiator that ultimately determines the
efficiency and effectiveness of any internetwork. The software-driven Cisco IOS
supports the evolution of all of today's strategic network platforms, whether
provided by Cisco or one of our technology partners. Because of these
attributes, the IOS is the key that has enabled Cisco to set the pace and
establish leadership standards in today's internetworking industry.
Cisco's IOS Mission: The IOS supports the evolution of all of
today's strategic network platforms
For more information on the Cisco IOS, call us today toll-free at 800
553-NETS (6387) or contact your local
Cisco sales office. Find
out how we can maximize the applications availability of your internetwork
while reducing your total cost of ownership. And we do it with the Cisco
Internetwork Operating System -- your strategic investment for the Information