Applying availability SLAs to traffic management systems

For today's Traffic Management Systems (TMS), availability is a key concern. Failures in the system limit its availability and have direct impact on the total cost of ownership (TCO) through additional maintenance costs. Therefore, availability parameters are often subject of contracts (so called Service Level Agreements (SLAs)) between system owners, maintenance contractors, and component vendors. With the growing complexity of such systems by means of multi-vendor environments consisting of various subsystems and components interconnected over numerous levels of hierarchy, enforcement of these agreements is getting a complex task. Therefore, advanced SLA enactment strategies are necessary, which include appropriate concepts that support the mapping of low-level resource metrics like the up- and down-time of a particular component to high-level application specific SLA-parameters (such as system availability). In this paper, we show the application of the LoM2HiS framework as an example technology for the automatic enforcement of availability SLAs in the field of TMS. We discuss possible SLAs for TMS and the required adoptions to the framework in order to meet the application-specific needs. Finally, we present first simulation results.