This paper uses two commercial datasets of IP addresses from smartphones, geolocated through the Global Positioning System (GPS), to characterize the geography of IP address subnets from mobile and broadband ISPs. Datasets that ge olocate IP addresses based on GPS offer superlative accuracy and precision for IP geolocation and thus provide an unprecedented opportunity to understand both the accuracy of existing geolocation databases as well as other properties of IP addresses, such as mobility and churn. We focus our analysis on large cities in the United States. After evaluating the accuracy of existing geolocation databases, we analyze the circumstances under which IP geolocation databases may be more or less accurate. We find that geolocation databases are more accurate on fixed-line than mobile networks, that IP addresses on university networks can be more accurately located than those from consumer or business networks, and that often the paid versions of these databases are not significantly more accurate than the free versions. We then characterize how quickly subnets associated with fixed-line networks change geographic locations, and how long residential broadband ISP subscribers retain individual IP addresses. We find, generally, that most IP address assignments are stable over two months, although stability does vary across ISPs. Finally, we evaluate the suitability of existing IP geolocation databases for understanding Internet access and performance in human populations within specific geographies and demographics. Although the median accuracy of IP geolocation is better than 3 km in some contexts, we conclude that relying on IP geolocation databases to understand Internet access in densely populated regions such as cities is premature.
翻译:本文使用来自智能手机的IP地址的两套商业数据集,这些数据库位于全球定位系统(GPS)的地理位置,以描述移动和宽带互联网服务供应商的IP地址子网的地理特征。基于全球定位系统的IP地址对IP定位提供超级准确性和精确性,从而为理解现有地理定位数据库的准确性以及IP地址的其他属性,例如流动性和杂质性提供了前所未有的机会。我们集中分析美国的大型城市。在评估现有地理定位数据库的准确性之后,我们分析了IP地理定位数据库可能越来越或更少准确的地理特征。我们发现,基于全球定位系统的地理定位数据库比移动网络更准确,大学网络的IP地址比消费者或商业网络的地址更准确,因此这些数据库的付费版本往往不会比自由版本更准确。我们然后将我们的分析重点放在固定的互联网网络连接地点改变地理位置的快速子网络,以及住宅宽带ISP用户保留个人IP地址的时间有多长。我们发现,一般来说,大多数IP地理定位数据库在固定线路上比移动网络网络数据库准确性更准确,尽管我们最终对具体地理定位的准确性进行了准确性评估。