Chapter10.Managing the Transport Infrastructure

Chapter 10. Managing the Transport Infrastructure

The transport infrastructure is the product of many interconnected network services. The customer's enterprise network, along with multiple Internet Service Providers (ISPs), hosting providers, and multiple business partners and supplier networks, comprises the transport infrastructure. IT and business managers must find ways of reducing costs by leveraging the public infrastructure while preserving, or even improving, customer service levels. Adequate bandwidth and the appropriate traffic priorities should be applied to the service mix, and service quality must be consistent even while the set of interconnected networking services changes.

End-to-end management is necessary so that all of the supporting individual networking services are at least monitored and held accountable for their contributions to overall service quality. In some cases, particularly situations in which traffic travels over the public Internet, direct service quality control and prioritization of all segments of the transport service may not be possible. Those situations call for a combination of approaches. In those parts of the network where it's possible, transport service quality can be controlled by using the approaches outlined in this chapter. In other parts of the network, strict Service Level Agreements (SLAs) and measurement, combined with appropriate selection of underlying transport services, can be used to assure that end-to-end transport quality is acceptable.

Monitoring of individual networking services provides measures that help select transport services and enforce SLAs; the revenues of network service providers are therefore partially determined by the service quality they provide. These measures can also help isolate a particular network environment when performance problems are indicated. Isolating the specific networking service speeds problem resolution and ensures that only the appropriate parties need to be involved in resolving the situation.

The ultimate goal is to design a network management approach that maintains high-quality service flows while being oriented toward solutions that use resources effectively and economically.

In this chapter, the following topics are covered:

• The low-level technical quality metrics that apply to transport services

• An introduction to Quality of Service (QoS) technology, which is used to control transport service quality

• The control and measurement of transport service quality when the traffic flows among separate organizations