For a comprehensive look at Traffic Control, it is important to understand basic HTTP/1.1 protocol operations and how cache servers function.

See also

For complete details on HTTP/1.1 see RFC 2616.

What follows is a sequence of events that take place when a client requests content from an HTTP/1.1-compliant server.

  1. The client sends a request to the LDNS server to resolve the name to an IP address, then sends an HTTP request to that IP.


    A DNS response is accompanied by a TTL which indicates for how long a name resolution should be considered valid. While longer DNS TTLs of a day (86400 seconds) or more are quite common in other use cases, in CDN use-cases DNS TTLs are often below a minute.

    #1 A Client Request for /foo/bar/fun.html from
    GET /foo/bar/fun.html HTTP/1.1
  2. The server at looks up the content of the path /foo/bar/fun.html and sends it in a response to the client.

    #2 Server Response
    HTTP/1.1 200 OK
    Content-Type: text/html; charset=UTF-8
    Content-Length: 45
    <!DOCTYPE html><html><body>This is a fun file</body></html>