Reliable and Time-efficient Virtualized Function Placement
Roi Ben Haim, Ori Rottenstreich · 2020
Reliability and time-efficiency are two key elements to consider in network design. Commonly, each is measured per service - availability probability of a specific service, the latency of a specific service, and overall - system average reliability and system average latency, considering the demand for every service. Intuitively, minimizing latency requires minimizing the number of network elements a service makes use of. In a non-redundant environment, this would also guarantee the maximal reliability of a service, as reliability degrades when the number of elements required to implement the service increases. However, reliability is often guaranteed by allocating redundant, backup resources. We explain that such redundancy or the joint support for multiple services can impose a trade-off between reliability and time-efficiency criteria. We design solutions that jointly take care of both design goals. Our analytical model considers networks following a virtualized paradigm - network functions are implemented on commodity servers and a network service is implemented by chaining functions. We examine how different assignment strategies impact reliability and time-efficiency.