According to Forrester Research, 22 percent of the Fortune 1000 companies currently use Web servers for internal applications, and another 40 percent are seriously considering their deployment in the near future. Zona Research predicts that by the year 2000 there will be nearly 3.3 million private intranet servers, as opposed to 650,000 for the public Internet. There are many forces driving organizations to migrate their internal information management systems to the intranet model:

• Intranets flatten the information delivery system within an organization, delivering content on demand. They foster the rapid exchange of information required to support reduced product life cycles, increased cost pressures, demand for customer service, and rapidly changing markets.

• The information on Web servers has the potential to be the latest and most accurate. Information can be cross-linked to provide point-and- click access to any other document within the organization or around the world.

• Intranets are based on open standards. This plays an important role in overcoming problems with incompatible computing environments (UNIX, MacOS, DOS, Windows 3.1, Windows 95, Windows NT, OS/2, VMS, etc.) that previously prevented universal access to information.

• Desktop browsers can be modified to function as the client interface for almost any client/server application. Since they are intuitive and extremely easy to use, browsers do not require a large investment in training.

• Intranets provide a high level of security. Many organizations do not have a direct connection to the global Internet, and if they are do, they can protect their intranet using an Internet firewall system. Java-enabled browsers support strong memory protection, encryption and signatures, and run-time verification.

Internet Firewall System

The prevailing desktop-centric model of computing is implemented by the deployment of heterogeneous fat clients. A fat client is a desktop system that is loaded with a complex operating system, local configuration files, a number of popular desktop
applications, and a variety of incompatible client applications for each network services. In contrast, the network-centric model of computing motivated by the corporate intranet is based on the deployment of thin clients with Java and/or ActiveX-enabled browsers.

By deploying thin clients, network managers can greatly reduce the complexity and administrative expense of running their networks. Sun Microsystems estimates that the annual cost of operating Java-based clients will be less than $2,500/desktop, compared to a $10,000 to $15,000/desktop range for today’s fat clients.

Thin Client Implementing a Java Webtop

Internet applications provide better performance within a corporate intranet than they do across the Internet. Most individual systems are connected to the Internet at data rates from 28.8/33.6 Kbps to the emerging 56 Kbps dial rates. Corporate users may have access at rates ranging from 128 Kbps (ISDN BRI) up to T1/E1 Mbps, but this may still seem relatively slow since the bandwidth is shared by many other workstations. In contrast, corporate intranets generally provide each desktop with access to local Web servers at data rates of 10/100 Mbps.

Intranets are based on inexpensive technology that is widely deployed in many private networks. If the enterprise has TCP/IP on its network, it can easily install Web servers and browsers. This allows organizations to slowly migrate to the intranet model without discarding a single computing platform or application.

Challenges for Network Managers

In many enterprises, the deployment of internal Web servers is a grassroots operation. The proliferation of HyperText Markup Language (HTML) editors has eased the burden of content creation, and Web servers are springing up all over organizations, in many cases without the knowledge or cooperation of the local network administrator or the traditional IS department. Network administrators who have been accustomed to carefully planning for traffic flows and bandwidth requirements associated with the rollout of a network operating system upgrade or a new client/server application are facing new challenges with the rapid migration to the intranet model:

• Internal Web sites with large graphic or multimedia content will make increasing bandwidth demands on the corporate infrastructure. The total volume of network traffic will grow as the content from bandwidth-intensive pages is transmitted across the organization’s infrastructure.

• The rollout of new applications based on Java and/or ActiveX applets can result in additional bandwidth and performance challenges. In the current client/server model, specialized client software is preinstalled on the user’s hard drive for each server that needs to be accessed. In the intranet model, applets are downloaded from the Web server to the client as they are needed. Although this greatly reduces LAN administrative costs, it can cause network congestion and slow response times.

• Intranet traffic flows will be impossible to predict and constantly changing. Since the goal of the intranet is to enable free exchange of information, network managers will not be able to predict in advance where the traffic bottlenecks will appear. In contrast to the traditional client/server model, in which large pipes can be provisioned to provide adequate bandwidth at the core of the network, user-developed Web servers are typically located on shared media at the edge of the network. The infrastructure at the periphery may not have sufficient capacity to support access from clients located across the enterprise. In addition, narrow WAN communication pipes may experience increased traffic volumes. Intranets can result in severe network congestion and performance problems at random locations across the enterprise network infrastructure.

• All of these changes will have a negative impact on the performance of existing client/server and legacy applications. These applications must now fight for basic bandwidth in a network environment in which there are increasing traffic volumes and unpredictable/unstable loads.

Supporting Intranet Applications

In an Intranet environment, it is imperative that network managers deploy RMON and RMON2 probes to gather baseline information about traffic flows and application trends. RMON and proactive monitoring are the keys to optimizing existing LAN and WAN resources, uncovering bottlenecks before they appear, establishing policies regarding the use of applications on the enterprise intranet, and making wise decisions about capacity planning and future growth.

After potentially disruptive trends are discovered via RMON/RMON2, network managers have several options meeting the challenges to efficient network operation. They can provide additional LAN bandwidth and improve performance by deploying layer 2 switches at the network edge. They can provide increased traffic control and packet throughput by deploying intelligent switches with Fast IP at the network core. Finally, they can use bandwidth-grooming features to overcome bottlenecks resulting from increased bandwidth demands on narrow WAN links.

Chuck Semeria, Courtesy: 3Com
For all further information, email at Sayan_Ghosh@3Com.com