re is some ambiguity in the nature of the fault. However, it is likely that, even in that situation, faults would continue to be logged with the OSS to maintain a central record of how much maintenance time particular NEs demand and how frequently particular NEs find themselves in a fault state. Many OSS applications allow complete control from an HTML interface. This means that a user needs only to be equipped with a web-enabled PC and a web browser in order to do their job. This reduces installation and support costs for the OSS and also allows distributed processing. From a human resources management viewpoint, web enablement makes it easy to spread workload over human resources in a way that is convenient given the peculiarities of the workforce of any service provider. See also Chapter 14 for more on recent advancements in web-based network management. Traffic Management 13.1 Introduction Traffic management is essential for the efficient flow of traffic through a network. This means that it is basic to the moment-to-moment running of a network. Traffic management is a key factor in QoS. Traffic management functionality provides advance warnings of performance-critical conditions so that network managers can re-route traffic before it affects QoS. Part of traffic management is real-time detection of network failures and correction of unavoidable network failures. This may allow users to be forewarned or otherwise proactively address the situation to minimise negative effects on QoS. A central purpose of any traffic management system is to provide visibility into the distribution of network traffic. This visibility must span both time and location. Information on distribution of network traffic is a prerequisite for more efficient use of existing equipment. If a traffic management system can operate across heterogeneous environments, then labour and operational costs are reduced because the information is available in a single location. Further, the single user interface to such a unified traffic man- agement 