# Performability Evaluation and Sensitivity Analysis of a Video Streaming on Demand Architecture
###### Abstract
Although promising, ISPs are not always ready to accept Open Connect Appliances (OCAs). ISPs must assess the specialized infrastructure needed to meet their customers' expectations with the help of Netflix infrastructure. The poor construction of this infrastructure can result in poor service, with crashes and delays. Platforms that integrate with certain streaming services must provide users with high availability and low latency for browsing and consuming multimedia content. The combination of availability and performance issues is referred to as performability. Evaluating the performance of such an architecture is important for aiding in the early design implementation, thereby reducing potential future issues. However, assessing the performance of this type of architecture is a complex task that involves multiple elements. In addition to being costly, such evaluations can be time-consuming, depending on the complexity of the system. As a result, the purpose of this paper is to assist ISPs in planning their infrastructure to adopt designs using various strategies to improve the performance and performability of OCA servers. Internet Service Providers (ISPs) typically have several key performance indicators (KPIs) that they use to measure the performance of their network and services. These KPIs may vary, depending on the specific goals and priorities of the ISP, as well as the characteristics of the network and the types of services being provided. Some common KPIs that ISPs may be interested in include:  
* _Network availability_: This refers to the percentage of time that the network is up and running, without any interruptions or outages [6; 7]. ISPs typically aim for high network availability, as it ensures that their customers can access the services that they need without disruption. * _Network latency_: This refers to the time it takes for data to be transmitted from one point to another within the network. Low latency is important for real-time applications such as online gaming and video conferencing, as it ensures that there is minimal delay in communication. * _Network throughput_: This refers to the amount of data that can be transmitted through the network in a given period of time. High throughput is important for applications that require large amounts of data to be transmitted, such as streaming video or downloading large files. * _Customer satisfaction_: This refers to the extent to which customers are satisfied with the quality and reliability of the ISP's services. ISPs may use various methods to measure customer satisfaction, such as surveys or customer service interactions. Stochastic Petri nets (SPNs) are a type of mathematical model that can be used to represent and analyze the behaviors of complex systems, including networks such as those used by Internet Service Providers (ISPs). In general, ISPs may be interested in using SPNmodels to accurately predict and analyze various aspects of their network, such as traffic patterns, network utilization, and performance. In terms of the specific characteristics of the modeled system, ISPs may be interested in modeling various aspects of their network, including the numbers and types of devices connected to the network, the patterns of traffic flow, and the capacity and utilization of different network resources. The accuracy of the model will depend on the quality and quantity of data available, as well as the complexity of the system being modeled. As for the granularity of the model, this will depend on the specific goals and needs of the ISP. For example, an ISP may be interested in modeling traffic patterns at a high level of detail in order to identify bottlenecks or to optimize network resources, or they may be interested in modeling traffic patterns at a more aggregated level in order to identify trends and patterns over time. In terms of specific KPIs, ISPs may be interested in using SPN models to predict and to analyze various metrics such as network availability, latency, throughput, and customer satisfaction.