Enabling content-aware traffic engineering

Abstract

Today, a large fraction of Internet traffic is originated by Content Delivery Networks (CDNs). To cope with increasing demand for content, CDNs have deployed massively distributed infrastructures. These deployments pose challenges for CDNs as they have to dynamically map end-users to appropriate servers without being fully aware of the network conditions within an Internet Service Provider (ISP) or the end-user location. On the other hand, ISPs struggle to cope with rapid traffic shifts caused by the dynamic server selection policies of the CDNs.The challenges that CDNs and ISPs face separately can be turned into an opportunity for collaboration. We argue that it is sufficient for CDNs and ISPs to coordinate only in server selection, not routing, in order to perform traffic engineering. To this end, we propose Content-aware Traffic Engineering (CaTE), which dynamically adapts server selection for content hosted by CDNs using ISP recommendations on small time scales. CaTE relies on the observation that by selecting an appropriate server among those available to deliver the content, the path of the traffic in the network can be influenced in a desired way. We present the design and implementation of a prototype to realize CaTE, and show how CDNs and ISPs can jointly take advantage of the already deployed distributed hosting infrastructures and path diversity, as well as the ISP detailed view of the network status without revealing sensitive operational information. By relying on tier-1 ISP traces, we show that CaTE allows CDNs to enhance the end-user experience while enabling an ISP to achieve several traffic engineering goals.

Effectiveness of Service-oriented Router for ISP-CDN Collaboration

“…Furthermore, Refs. [7], [47] show that the ISPs should perform adequate routing and enduser redirection in small time scales, and the traffic matrix should be considered as a parameter for the network path selection [51]. Subsequently, the obtained results showed that, by placing SoRs at the edges of ISP networks, the SoRs could be used to leverage DNS-based CDN redirection to achieve end-user redirection in small time scales.…”

“…As previously stated, various studies such as Refs. [7], [8], [9], [11] pointed out the necessity of ISP-CDN collaboration to achieve this objective. ISP-CDN collaboration can be explained as the process that ensures the end-users are redirected to the best server via the best path.…”

“…In Ref. [7], authors proposed ISP-CDN collaboration. Authors used the traffic matrix of the CDN for TE, and hence, proposed to redirect end-users to the nearest content servers in small time scales.…”

“…However, CDNs redirect their subscribers without being acutely aware of the ISP network conditions [7]. ISPs, on the other hand, blindly route huge volumes of traffic introduced by CDNs without considering the traffic matrix of CDNs as a parameter for route selection [8], [9].…”

“…To this end, several recent studies [7], [8], [9], [11] indicated the necessity of ISP-CDN collaboration for foreseeable improvements of either RR or network resource utilization. Similarly, we discussed the effectiveness of edge routers for accelerating the CDN RR process [12].…”