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 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 nonredundant environment, this would also guarantee the maximal reliability of a service, as reliability degrades when relying on more elements. However, reliability is often guaranteed by allocating backup resources. We explain that such redundancy or the joint support for multiple services can impose a tradeoff between reliability and time-efficiency criteria. In this article, we study the conditions for the existence of such a tradeoff and design solutions that jointly take care of both design goals.

中文翻译：

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可靠且省时的虚拟功能放置

可靠性和时间效率是网络设计中要考虑的两个关键要素。通常，每项服务均按每种服务的需求进行衡量-特定服务的可用性概率，特定服务的延迟以及整体-系统平均可靠性和平均延迟。直观地，最小化等待时间需要最小化服务使用的网络元素的数量。在非冗余环境中，这也将保证服务的最大可靠性，因为在依赖更多元素时可靠性会降低。但是，通常可以通过分配备份资源来保证可靠性。我们解释说，这种冗余或对多种服务的联合支持可能会在可靠性和时间效率标准之间进行折衷。在这篇文章中，