After discussing the various aspects of accounting and
performance management, now we want to relate the information to the
business. How can the two areas help you design and operate a productive, reliable, and cost-efficient network? During the Internet hype, revenue generation and assurance were certainly not the center of attention, but this changed quickly when the global economic slowdown started. Today, if a network architect develops a new design or extends the existing design, a solid business case needs to be in place to rationalize the investment and calculate a quick return on investment, or the project might never kick off. Therefore, you need answers to the following questions:
How can accounting and
performance management increase revenue for a service provider?
Can it help an enterprise to better utilize the network equipment and identify bottlenecks in the network, so that only these bottlenecks are resolved by an upgrade instead of upgrading the entire network?
Can you justify an investment in accounting to increase revenue assurance?
Will accounting and performance management help reduce the operational expenses?
Can you classify the most- and least-profitable areas and access points of a service provider network?
The related costs of usage reporting are a major deterrent that might stop administrators from considering accounting a valuable solution for their network. Three main areas are related to these concerns:
Collection overhead— Based on the selected technique, generating usage data records at the device level can create a significant resource impact on the device CPU utilization and can require additional memory and bandwidth utilization when exporting the data records to an external collector. This needs to be considered in the proposed accounting and performance management architecture.
Mediation, processing, and reporting overhead— Additional resources are required to collect the records and aggregate and mediate them afterwards. At this point, the collection contains only data (collected usage records) and not processed information, such as end-to-end performance records, a list of security attacks during the last month, or a printable invoice for a customer. The next step is processing the data at a performance, security, planning, or billing application, which creates useful information for the NOC personnel. The costs of these applications cannot be neglected; even open-source software has related costs of server hardware and administration expenditures.
Security overhead— A huge benefit of collecting accounting records is its inherent multipurpose functionality. As mentioned, multiple applications can benefit from data collection, which results in a "collect once and reuse multiple times" proposal. Imagine the disaster that happens when data sets have been manipulated. If multiple applications base their results on wrong data sets, the whole network operation is jeopardized. This is not limited to a customer''''s invoice, but also to network planning and especially security analysis. As soon as an attacker detects the corporate accounting architecture, he or she can manipulate data sets and bypass the traffic meters that were put in place to identify security threats. It is critical to implement mechanisms to protect accounting information from unauthorized access and manipulation.
A possible approach to address the collection overhead and security overhead issues just mentioned is to deploy a Data Communications Network (DCN). The DCN concept was developed in the service provider context, but it can also be useful in an enterprise environment, where it is usually referred to as out-of-band (OOB) management. What is a DCN? A DCN is a standalone out-of-band network providing connectivity between the network operations center (NOC) and the network elements, remotely and independently of the user traffic. The opposite approach is called in-band-management, where man