The focus of this chapter was to provide relevant details on general architectures, standard definitions, and protocols and their relationship to performance and accounting management. Because of the variety of standards, you might feel overwhelmed when selecting a standard. Therefore, keep in mind that the variety of user requirements was one reason for multiple standards definitions. The first step should always be to determine your requirements and objectives precisely and then to identify the standard that matches all or most of your requirements. Best practice suggests starting with the TMN layered architecture and FCAPS, which can help with mapping requirements to operational areas and product functionalities. From a device perspective, SNMP is necessary in most cases; the challenge is to identify the right version (2c or 3). For consistent results with accounting and performance measurement, applying IPFIX and PSAMP is suggested: IPFIX for the exporting protocol, and PSAMP for the metering process if sampling, filtering, or hashing is required. However, while waiting for IPFIX and PSAMP to become widely available in the Internet, the network administrator should focus on NetFlow as a metering and exporting process. (NetFlow version 9 offers a wide range of information elements.) IPDR is applicable if multiple collection or mediation applications should cooperate. Specifically, for service providers, TMF's eTOM model can be very helpful to define and implement customer-oriented processes. However, even though all these standards organizations are valuable, there might still be situations in which you need a specific feature that only one vendor offers and no standard covers yet. If this specific feature helps you gain additional revenues or reduce costs, there is no need to wait for a standard; select this innovative vendor. Except for these situations, it is always the right decision to build your network based on standards!
Table 3-12 summarizes the different standards covered in this chapter.
Table 3-12. Standards Summary
|Standard||Where to Apply It|
|ITU-T (FCAPS)||Defining specific areas of network management functionality. Providing a matrix to map requirements and products.|
|TMF (eTOM, FAB, GB917)||Operational and business procedures in a service provider environment.|
|SNMP||Basic network management functionality.|
|CMIP/CMISE||Complex and advanced network management functionality.|
|IETF (IPFIX)||Export protocol for flow metering at network elements.|
|IETF (PSAMP)||Definition of sampling technologies for network elements.|
|IETF (AAA)||Accounting standard in dial-in and wireless environments.|
|IPDR||Standard for interoperability between mediation and accounting applications.|