Most CDNs take advantage of DNS to intercept and redirect requests. Figure
3
shows an
example of how DNS is typically involved. Suppose a content provider, NBC SPORTS,
employs the third
-
party CDN company, Akamai, to distribute its videos to customers.

Question

Most CDNs take advantage of DNS to intercept and redirect requests. Figure 
3
 ﻿shows an
example of how DNS is typically involved. Suppose a content provider, NBC SPORTS,
employs the third
-
party CDN company, Akamai, to distribute its videos to customers.

Accepted Answer

⚹ The student's question seems to be about how Content Delivery Networks (CDNs) like Akamai use the Domain Name System (DNS) to serve content, such as videos from NBC SPORTS, to customers efficiently. ⚹ ⚹ When a user wants to access content from NBC SPORTS, which uses Akamai's CDN services, the following steps typically occur: ⚹ ‖ ▪ ⋮ User Request: A user requests NBC SPORTS content, such as a video, by typing the URL into their browser. ‖ ‖ ▪ ⋮ DNS Query: The user's browser sends a DNS query to resolve the domain name to an IP address. ‖ ‖ ▪ ⋮ DNS Redirection: Instead of returning the IP address of NBC SPORTS's origin server, the DNS query is intercepted by Akamai's DNS servers. ‖ ‖ ▪ ⋮ Optimal Server Selection: Akamai's DNS servers use algorithms to select the optimal edge server that is closest to the user or has the best performance at that moment. ‖ ‖ ▪ ⋮ IP Address Response: Akamai's DNS servers respond to the DNS query with the IP address of the selected edge server. ‖ ‖ ▪ ⋮ Content Delivery: The user's browser connects to the provided IP address, which is an Akamai edge server, and the requested content is delivered from this server to the user's device. ‖ ⚹ By using DNS in this way, CDNs can distribute the load, reduce latency, and increase the availability of content. ⚹

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