worker sites: Mobile users tend to access the company network using an asynchronous dialup connection through the telephone company or access the corporate intranet using broadband Internet service and the VPN client software on their laptops. Teleworkers working from home can also use a VPN tunnel gateway router for encrypted data and voice traffic to and from the company intranet. These solutions provide simple and safe access for branch offices or SOHOs to the corporate network site according to the needs of the users at the sites.

Content 1.1 Enterprise Networking 1.1.4 Remote Connection Considerations These are the typical considerations for setting up a remote-site WAN connection as shown in Figure :

Multiple access options: Remote users connect to the branch site using various media. Branch site WANs must allow for multiple media options and simultaneous access by multiple users. The branch office must also have connectivity to the central or small home/small office (SOHO) site. Although a remote site may have a variety of equipment, the site does not require the same level of complexity as the central site requires. Examples of WAN technologies that are used to connect a remote site to the central site include:
- Leased line
- Broadband services (cable or DSL)
- Frame Relay
- ISDN (still in use but becoming a legacy technology)
Cost: Depending on the traffic types and connectivity requirements, designers typically consider various connectivity options including permanent or on-demand, public and private networks, and other options as required.
Access control: To prevent unauthorized traffic, routers and firewalls use a set of rules that permit or deny certain traffic. IT staff apply access control to router interfaces and configure them to control which data sessions pass and which sessions fail.
Secure connectivity: Remote sites and mobile workers can gain secure access to corporate intranets by using VPN solutions, such as IPsec VPN or MPLS VPN.
Authentication: The remote site must be able to authenticate itself to the central site.
Redundancy: In internetworking, duplicate devices, services, or connections can perform the work of original devices, services, or connections in the event of a failure. Branch offices typically require more redundancy than SOHOs or mobile teleworkers.
Infrastructure availability: Service providers may not offer certain WAN services in some regions. This consideration generally becomes more critical as sites are set up in more remote locations.

Example: Integrated Services for Secure Remote Access
Figure shows an example of a converged network with integrated services. Many companies have upgraded their remote connections using modems and dial up access and now use digital subscriber line (DSL) and cable as advanced physical layer technologies. They also use MPLS VPNs and IPsec VPNs as two of the advanced secured connectivity technologies. Broadband technology uses existing telephone and cable television infrastructures to provide high-speed access to the Internet. Generally, a speed of 128 kbps is adequate for most users. However, while there is no universal definition of broadband, Cisco uses the U.S. Federal Communications Commission (FCC) definition of advanced telecom or high speed to be 200 kbps or greater. Broadband allows remote office staff and SOHO users to connect to the central site at higher data rates than are available with traditional on-demand technologies. High-speed broadband access to the Internet through a broadband point of presence (PoP) and then to corporate networks using secure VPNs is a reality for many users in the networked world today. This broadband access has the potential to improve employee productivity and to provide a foundation for new voice and video business services over the Internet. Many corporations and educational institutions have instituted broadband solutions for access by suppliers, customers, and staff. The use of the Internet for secure site-to-site connectivity using VPNs is increasing, especially for less critical traffic.

Content 1.1 Enterprise Networking 1.1.5 Intelligent Information Network The Cisco Intelligent Information Network (IIN) vision is a strategy that meets the evolving role of the network within businesses and directly meets the need to align information technology (IT) resources with business priorities. The Cisco IIN vision has three key features:

Integration of networked resources and information assets: Modern networks with integrated voice, video, and data allow IT departments to link the IT infrastructure more closely with the information network.
Intelligence across multiple products and infrastructure layers: The intelligence built into each network component extends network wide and applies end-to-end.
Active participation of the network in the delivery of services and applications: With added intelligence within network devices, the IIN makes it possible for the network to actively manage, monitor, and optimize service and application delivery across the entire enterprise environment.

With these features, the IIN offers much more than basic connectivity, bandwidth for users, and access to applications. The IIN offers end-to-end functionality and a centralized, unified control that promotes true business transparency and agility. The IIN vision offers an evolutionary approach. Functionality can be added to existing network infrastructure as required in three phases:

Integrate transport: IIN consolidates data, voice, and video into an IP network for secure network convergence. By integrating data, voice, and video transport into a single, standards-based, modular network, organizations can simplify network management, generate enterprise wide efficiencies and reduce infrastructure costs. Network convergence also lays the foundation for a new class of IP-enabled applications delivered through Cisco IP Communications solutions.
Integrate services: When convergence is complete, the network will pool and share, or virtualize, resources to meet the changing needs of the organization more flexibly. Integrated services unify common elements including storage and data center server capacity. By extending virtualization capabilities to encompass server, storage, and network elements, an organization can use all of its resources more efficiently. In addition, shared resources across the IIN provide services in the event of a local systems failure, which enhances business continuity.
Integrate applications: The third phase is Application-Oriented Networking (AON). AON focuses on making the network “application aware” so that the network can optimize application performance and deliver networked applications to users more efficiently. In addition to capabilities such as content caching, load balancing, and application-level security, Cisco AON makes it possible for the network to simplify the application infrastructure by integrating intelligent application message handling, optimization, and security into the existing network.

Content 1.1 Enterprise Networking 1.1.6 Cisco SONA Framework IIN helps organizations meet new IT challenges including deploying service-oriented architectures, web services, and virtualization. Cisco Service-Oriented Network Architecture (SONA) is an architectural framework that details the set of common services that are deployed in the network to close gaps between the resources and applications. Cisco SONA describes how to build an IIN. The Cisco SONA framework provides these advantages to enterprises as shown in Figure :

Outlines the path toward the IIN
Illustrates how to build integrated systems across a fully converged IIN
Improves flexibility and increases efficiency resulting in