4.1. Network Design Considerations

Many factors are involved in making network design decisions. First and foremost, you need to understand the design of the Oracle network architecture itself. Oracle Net is flexible and configurable and has the scalability to accommodate a range of network sizes. You can choose from a variety of network configurations that are designed to meet the needs of both small and large organizations. The sections that follow summarize the areas that you need to consider.

4.1.1. Network Complexity Issues

The complexity of the network plays an important role in many of your network design decisions. To determine network complexity, you need to answer the following questions:

• How many clients will the network need to support?

• What type of work will the clients be doing?

• Where are the clients? In complex networks, clients can be geographically dispersed over a wide area.

• What types of clients are going to be supported? Will they be PC-based or terminal-based? Will these be thin clients that do little processing or fat clients that do most of the application processing?

• What is the projected growth of the network?

• Where will the processing take place? Will any middle-tier servers be involved, such as an application server or a transaction server?

• What types of network protocols will be used to communicate between the clients and servers?

• Will Oracle servers have to communicate with other Oracle servers in the enterprise?

• Will the network involve multiple operating systems?

• Do the applications that will be used require any special networking? This is especially important to consider when you are dealing with third-party applications.

Answering these questions will provide you with guidance in determining the size and amount of the network hardware and software required to monitor and manage the network. You will also start to gain insights into the staffing levels and time requirements needed to support the network.

4.1.2. Network Security Issues

Network security has become even more critical as companies expose their systems to larger and larger numbers of users through Internet and intranet connections. To determine the security of a network, you need to answer the following questions:

• Does the organization have any special requirements for secure network connections? What kinds of information will be sent across the Oracle network?

• Can you ensure secure connections across a network without risk of information tampering? This may involve sending the data in a format that makes it tamper-proof and also ensures that the data cannot be captured and read by parties other than the client and the intended Oracle server.

• Is there a need to centralize the authorizations that an individual has to each of the Oracle servers? In large organizations that have many Oracle services, this can be a management and administration issue.

Once you gain an understanding of what the network security requirements are, you should know the following:

• The network hardware and software requirements

• The modifications to applications to meet these security requirements

• The policy and procedure changes within the organization to meet the requirements

• The staffing levels to monitor and manage security

4.1.3. Interfacing Existing Systems with New Systems

Many organizations are faced with the challenge of interfacing legacy systems to new systems. Often these legacy systems contain mission-critical information, and must be able to communicate to new applications as the business evolves. If existing computer systems must communicate with Oracle server networks, you need to answer the following questions:

• Does the application that needs to perform the communication require a seamless, realtime interface?

• Does the existing system use a non-Oracle database such as IBM DB2 or Microsoft SQL Server?

• Will information be transferred periodically from the existing system to the Oracle server? If so, what is the frequency and which transport mechanisms should be used? Will the Oracle server need to send information back to the existing system?

• Do applications need to gather data from multiple sources, including Oracle and non-Oracle databases, simultaneously?

• What are the applications involved that require this interface?

• Will these network requirements necessitate design changes to existing systems?

Answering these questions will give you a better understanding of what systems need to be able to communicate with Oracle Net and to what degree these systems need to be integrated.

4.1.4. Network Responsibilities for the DBA

As a database administrator, you have many design issues to consider when implementing a network of Oracle servers in the enterprise. Here are some of your key responsibilities:

• Understand the network configuration options available and know which options should be used based on the requirements of the organization.

• Understand the underlying network architecture of the organization in order to make informed design decisions.

• Work closely with the network engineers to ensure consistent and reliable connections to the Oracle servers.

• Understand the tools available for configuring and managing the network.

• Troubleshoot connection problems on the client, middle tier, and server.

• Ensure secure connections and use the available network configurations, when necessary, to attain higher degrees of security for sensitive data transmissions.

• Stay abreast of trends in the industry and changes to the Oracle architecture that might have an impact on network design decisions.