Modern converged networks include differeni iraffic types, each with unique requirements for security, QoS, transmission capacity, and delay. These include:

■ Voice signaling and bearer

■ Core application traffic, such as Enterprise Resource Planning (ERP) or Customer Relationship Management (CRM)

■ Database transactions

■ Multicast multimedia

■ Network management

■ Other iraffic, such as web pages, e-mail, and file transfer

Cisco routers are able to implement filtering, compression, prioritization. and policing. Except for filtering, these capabilities are referred to collectively as QoS.


The best way to meet capacity requirements is to have twice as much bandwidth as needed. Financial reality, however, usually requires QoS instead.

Although QoS is wonderful, it is not the only way to address bandwidth shortage. Cisco espouses an idea called the Intelligent Information Network (UN).

UN describes an evolutionary vision of a network that integrates network and application functionality cooperatively and allows the network to be smart about how it handles traffic to minimize the footprint of applications. UN is built on top of the Enterprise Composite Model and describes structures overlaid on to the Composite design as needed in three phases.

Phase 1, "Integrated Transport," describes a converged network, which is built along the lines of the Composite model and based on open standards. This is the phase that the industry has been transitioning to recently. The Ciseo Integrated Services Routers (ISR) are an example of this trend.

Phase 2, "Integrated Services." attempts to virtualize resources, such as servers, storage, and network access. It is a move to an "on-demand" model.

By "virtualize," Cisco means that the services are not associated with a particular device or location. Instead, many services can reside in one device to ease management, or many devices can provide one service that is more reliable.

An ISR brings together routing, switching, voice, security, and wireless. It is an example of many services existing on one device, A load balancer, which makes many servers look like one, is an example of one service residing on many devices.

VRFs are an example of taking one resource and making it look like m;iny. Some versions of IOS are capable of having a router present itself as many virtual router (VRF) instances, allowing your company to deliver different logical topologies on the same physical infrastructure. Server virtualization is another example. The classic example of taking one resource and making it appear to be many resources is the use of a virtual LAN (VLAN) and a virtual storage area network (VSAN).

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Visualization provides flexibility in configuration and management.

Phase 3, "Integrated Applications," uses application-oriented networking (AON) to make the network application-aware and to allow the network to actively participate in service delivery.

An example of this Phase 3 UN systems approach to service delivery is Network Admission Control (NAC). Before NAC, authentication, VLAN assignment, and anti-virus updates were separately managed. With NAC in place, the network is able to check the policy stance of a client and admit, deny, or remediate based on policies.

UN allows the network to deconstruct packets, parse fields, and take actions based on the values it finds. An ISR equipped with an AON blade might be set up to route traffic from a business partner. The AON blade can


examine traffic, recognize the application, and rebuild XML files in memory. Corrupted XML fields might represent an attack (called schema poisoning), so the AON blade can react by blocking that source from further communication. In this example, routing, an awareness of the application data How, and security are combined to allow the network to contribute to the success of the application.

Services-Oriented Network Architecture (SONA) applies the UN ideal to Enterprise networks. SONA breaks down the UN functions into three lay el's:

■ Network Infrastructure—Hierarchical converged network and attached end systems.

■ Interactive Services—Resources allocated to applications.

■ Applications—Includes business policy and logic.

IIN Phases SONA Framework Layers

Phase 3 - Integrated Applications

("application aware")



Business Apps

s 1

Collaboration Apps

a <




Application Networking Services

Phase 2 - Integrated Services (virtualized resources)

Application Networking Services

Infrastructure Services

Phase 1 - Integrated Transport (converged network)

s „


I Storage |

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IP Routing Protocols

Routing protocols are used to pass information about the structure of the network between routers. Cisco routers support the following IP routing protocols RIP {versions I and 2), JGRP. E1GRP, IS-IS, OSPF, and BGP. This section compares routing protocols and calls out key differences between them.

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