(RTTMS). There are various events which can have a serious effect on the service provision. Undesirable spikes in traffic load require some response from network manage- ment to ensure that services continue to be provided. The following undesirable effects are associated with such spikes: Abnormal increases in traffic demand due to foreseen events such as national or religious holidays, or an international sporting event. Traffic demand can also increase unusually because of unforeseen events such as natural disasters or political crises. Focused overloads and mass calling, such as for telemarketing campaigns. Congestion in connected networks. Delays in the provision of additional circuits or equipment. Failures or planned outages of transmission systems and exchanges. Long duration of calls to ISPs. Increased traffic load due to intelligent network services. Figure 13.1 RTTMS - network overview window. OSS for Telecom Networks These events can lead to congestion, which, if uncontrolled, may seriously degrade the quality of service and generate loss of revenue for the network operator. With the aid of the RTTMS, overload situations can be dealt with promptly and network capacity utilization can be optimised. This can result in increased return on the cap- ital invested in the network and in an improved ratio of effective to ineffective calls. 13.7.2 Vitesse The hardware-based traffic management products offered by Vitesse provide policing, congestion management, quality provisioning through shaping and sched- uling, interworking and switching of layer 2, 3 and 4 data packets and ATM cells. This applies up to bandwidths of several Gbps. Interworking is also referred to as Segmentation and Reassembly (SAR). The Vitesse Traffic Management Line includes three product families: PaceMaker: OC-48 Traffic Manager with ATM SAR Monitor: OC-48 ATM OAM and Protection Switching Processor OSCAR: OC-48 AALS SAR with Traffic Manager. The benefits that the Vitesse traffic management suite seeks to deliver are: integration enabli