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Content 1.2 Scalable Networks 1.2.5 Making the Network Efficient An efficient network should not waste bandwidth, especially over costly WAN links. To be efficient, routers should prevent unnecessary traffic from traversing the WAN and minimize the size and frequency of routing updates. Cisco IOS includes several features designed to optimize a WAN connection:
Content 1.2 Scalable Networks 1.2.6 Making the Network Adaptable An adaptable network should be able to handle the addition and coexistence of multiple routed and routing protocols, including:
Content 1.2 Scalable Networks 1.2.7 Making the Network Accessible But Secure Accessible networks let users connect easily over a variety of technologies. Campus LAN users typically connect to routers at the access layer through Ethernet. Remote users and sites may have access to several types of WAN services. Cost and geography play a significant role in determining what type of WAN services an organization can deploy. Therefore, Cisco routers support all major WAN connection types. As shown in Figure , these services include all of the following: Dialup and dedicated access: Cisco routers can be directly connected to basic telephone service or digital services such as T1/E1. Dialup links can be used for backup or remote sites that need occasional WAN access, while dedicated leased lines provide a high-speed, high-capacity WAN core between key sites. Packet-switched: Cisco routers support Frame Relay, X.25, Switched Multi-megabit Data Service (SMDS), and ATM. With this variety of support, which WAN service, or combination of WAN services, to deploy can be determined based on cost, location, and need. Often, the easier it is for legitimate remote users to access the network, the easier it is for unauthorized users to break in. An access strategy must be carefully planned so that resources, such as remote access routers and servers, are secure. Network Access Control (NAC) and Identity Based Network Services (IBNS) should be implemented to ensure secure access. Web Links Network Admission Control (NAC) Framework
http://www.cisco.com/en/US/netsol/ns617/
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Identity Based Networking Services Solution
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Content 1.3 Converged Networks 1.3.1 Traffic Conditions in a Converged Network Converged networks with integrated voice, video, and data contain various traffic patterns: The diversity of the traffic mix poses stringent requirements on the network in terms of performance and security. The requirements significantly differ, depending on the traffic type. For example, voice and video require constant bandwidth and low delay and jitter, while the transactional traffic requires high reliability and security with relatively low bandwidth. Video traffic is frequently carried as IP multicast traffic. Also, voice applications, such as IP telephony, require high reliability and availability because the user expectations for “dial tone” in the IP network are exactly the same as in traditional phone network. To meet the traffic requirements in the network, voice and video traffic must be treated differently from other traffic, such as web-based traffic. QoS mechanisms are mandatory in converged networks. Security is a key issue not only in fixed networks but also in wireless mobility, where access to the network is possible virtually anywhere. Several security strategies, such as device hardening with strict access control and authentication, intrusion protection, intrusion detection, traffic protection with encryption, and others, can minimize or even totally remove network security threats.
Content 1.3 Converged Networks 1.3.2 Routing and Routing Protocols The focus of this course is on selecting, planning, implementing, tuning, and troubleshooting IP advanced routing protocols. All the models and tools described previously are important in the initial part of this process—selecting and planning. The best practice is to use one IP routing protocol throughout the enterprise, if possible. In many cases, this practice is not possible, which will be discussed in detail in another module. For example, BGP is a factor in the corporate Internet and e-commerce modules if multihoming to ISPs is implemented. For remote access and VPN users, static routes are almost always used. Therefore, dealing with multiple routing protocols is likely. The ECNM can assist in determining where each routing protocol is implemented, where the boundaries are, and how traffic flows are managed. It is obvious that advanced IP routing protocols must be implemented in all core networks to support high-availability requirements. Less advanced routing protocols, such as RIP and static routes, may exist at the access and distribution levels within modules. Figure represents a simple comparison of three IP routing protocols. The remainder of this course consists of technical detail on each of these, as well as BGP, IP multicast, and IP version 6 (IPv6).
Content 1.4 ITA Topology 1.4.1 Overview of the International Travel Agency The labs in this course reference the fictitious International Travel Agency (ITA), which maintains a global data network. The ITA business scenario provides a tangible, real-world application of the concepts introduced in the labs. Use the diagram of the ITA WAN topology in Figure to become familiar with the global location of the company and its network.
Content 1.4 ITA Topology 1.4.2 The ITA Logical Topology Figure provides a logical view of the ITA network topology.
Content 1.5 Overview of Course Labs 1.5.1 Lab 1-0 TCL Script Reference and Demonstration Lab Activity

Lab Exercise: Lab 1-0 TCL Script Reference and Demonstration
Content Summary This module defined scalability and provided examples of network design that enable successful network expansion. It highlighted the network as the platform and explained Cisco’s vision of the future with the Intelligent Information Network (IIN) and the Service-Oriented