1. Explain the term network management in one sentence.
Answer: Network management refers to the activities, methods, procedures, and tools that pertain to the operation, administration, maintenance, and provisioning of networked systems.
2. We used a patient in intensive care as one analogy to explain network management. Can you think of areas in network management that this analogy does not capture?
Answer: For example, the analogy does not effectively capture the administration and provisioning aspects of network management.
3. Can you think of other areas in which you would expect analogies to network management to apply?
Answer: Monitoring, planning, and control are involved in many areas—for example, running a railroad, controlling a space mission, and controlling a nuclear power plant.
4. Give two examples of how network management can help an enterprise IT department save money.
Answer: One example concerns the capability to more efficiently localize network failures. This means that less time (and money) is spent on troubleshooting and network technicians are dispatched more effectively. Another example involves the automation of routine tasks to offload operating personnel.
5. Give two examples of how network management can help a service provider increase revenue.
Answer: For example, the capability to turn up service for more customers faster means that more revenue can be collected earlier. A second example concerns being able to offer new communication services that result in new revenue streams, whose cost would be prohibitive without corresponding management capabilities.
6. A famous requirement for availability is “five nines.” This refers to the requirement that a device or a service must be available 99.999 percent of the time. Assume that you have a device with hardware availability of 99.9995 percent. Now assume that an operational error is made that causes the device to go offline for 5 minutes until the error is corrected. Calculated over a period of a month, how much has the operational error just caused availability to drop?
Answer: Availability dropped from five nines to three nines. That means the system would be considered two orders of magnitude less available than before. (30 × 24 × 60 × 60 = 2,592,000 seconds in a month. The rate of 99.9995 percent means that the system would have been available for 2,591,987 seconds had the operational error not occurred. With the 5 minutes of additional downtime, it was available only for 2,591,687 seconds, or 99.988 percent—in other words, three nines.)
7. How does the perspective under which network management is approached often differ for an enterprise IT department compared to a service provider?
Answer: Network management is a competitive differentiator for service providers—the service provider that runs the network in the best possible way wins in the marketplace. Therefore, there is a tendency for service providers to invest heavily in operations support infrastructure, including custom development where necessary, because this is critical to their business. On the other hand, network management is viewed more under cost considerations in the enterprise IT department—accordingly, there is greater reliance on commercial off-theshelf management applications.
8. Name at least two factors that can be important to the business success of a third-party management application vendor that potentially has to compete with a network management offering of a network equipment vendor.
Answer: Factors that could be important include the capability to support multiple vendors, application extensibility to provide easy support for new types of equipment for faster time to market, and orientation more toward management of communications services and operational processes than network equipment.
9. What does the term swivel-chair syndrome refer to, and why is this undesired?
Answer: It refers to the problem of a lack of integration between management applications, requiring network operators to use multiple terminals at once and thereby needing to “swivel the chair” to switch between those terminals to perform their job. Swivel-chair syndrome is undesirable for many reasons, including the capital and administration expense for additional terminals, additional training cost, lack of qualified personnel, potential for things to “fall through the cracks,” and general operational inefficiencies.
10. Name two or more reasons for network management applications to be approached as distributed systems.
Answer: Management applications are inherently of a distributed nature because they involve communication among multiple systems (management systems and network equipment). In addition, distributed systems help to address scaling requirements that might require the capability to add hardware to increase horsepower, resilience requirements that might require support for failovers between systems in case individual systems fail, and requirements to support follow-the-sun operations across geographically diverse regions.