"A collection of interconnected networks" defines what the Internet is, but not what it is not. Events threaten Internet fragmentation: politics suggest countries or ISPs may secede or be de-peered, disputes between ISPs result in persistent unreachability between their customers, and architectural changes risk breaking the "one" Internet. Understanding such threats benefits from a testable definition of what the Internet is and is not, enabling discussion and quantification of partial connectivity. We provide a conceptual definition giving an idealized asymptote of connectivity. It implies peninsulas of persistent, partial connectivity, and islands when one or more computers are partitioned from the main Internet. We provide algorithms to measure, operationally, the number, size, and duration of peninsulas and islands. We apply these algorithms in rigorous measurement from two complementary measurement systems, one observing 5M networks from a few locations, and the other a few destinations from 10k locations. Results show that peninsulas (partial connectivity) are about as common as Internet outages, quantifying this long-observed problem. Root causes show that most peninsula events (45%) are routing transients, but most peninsula-time (90%) is from a few long-lived events (7%). Our analysis helps interpret DNSmon, a system monitoring the DNS root, separating measurement error and persistent problems from underlying differences and operationally important transients. Finally, our definition confirms the international nature of the Internet: no single country can unilaterally claim to be "the Internet", but countries can choose to leave.
翻译:“互联网络的集合”定义了互联网是什么,但并没有定义它不是什么。事件威胁着互联网的分裂:政治上的国家或 ISPs 可能会退出或被取消互联, ISPs 之间的争议导致它们的客户之间持续的无法互联,架构变化会冒着破坏“一个”互联网的风险。了解此类威胁有助于测试互联网是什么和不是什么的可验证定义,从而使部分连接性得到讨论和量化。我们提供了概念化的定义,给出了连接性的理想渐近线。这意味着持续的、部分的连接性半岛和一个或多个计算机与主要互联网分离时的岛屿。我们提供了算法来量化操作测量半岛和岛屿的数量、大小和持续时间。我们将这些算法应用于两个互补的测量系统的严格测量中,一个从少数地点观察 500 万个网络,另一个从 1 万个位置观察少数目的地。结果表明,半岛(部分连接性)与互联网宕机大约同样普遍,量化了这个长期观察到的问题。根本原因表明,大多数半岛事件(45%)是路由瞬态,但大多数半岛时间(90%)来自少数持久事件(7%)。我们的分析有助于解释 DNSmon,一种监测 DNS 根的系统,将测量误差和持久性问题与基本差异和操作上重要的瞬态分开。最后,我们的定义证实了互联网的国际性:没有一个国家可以单方面声称自己是“互联网”,但国家可以选择退出。