Spread of IP Anycast and GSLB

Abstract

Content Delivery Networks (CDN) are regarded as an important internet infrastructure that supports business on the Internet. Network latency has been identified as an important metric to improve the quality of service (QoS) of CDNs. Given the limitations to response times because of the geographic distance between servers and end-users, CDN providers have developed architectures such as Global Server Load Balancing (GSLB) and IP Anycast to realize fast responses. This study investigates how GSLB and IP Anycast contribute towards improving QoS from the users' perspective. User traffic in the campus network was analyzed and it was found that: 1) 93.8% of the traffic reaps the benefits of well operated internet services, i.e., they have a Round-Trip Time (RTT) of less than 0.1 second. 2) Although GSLB is still the primary architecture for realizing fast responses, IP Anycast supports 5.9% of the traffic.