Content delivery network (CDN) is a content delivery acceleration service provided based on the network nodes of eSurfing Cloud distributed all over the world. It distributes content from origins to edge nodes closest to the user so that the user can obtain the required content nearby. This solves the issue of access delay caused by cross-operator access, cross-region access, server bandwidth and performance and increases the response speed and success rate of user access. CDN is applicable to the scenarios such as website acceleration, file download and on-demand streaming and provides users with a stable and high-quality acceleration service.