# HTTP request/response — browser resolves DNS, hits CDN, CDN fetches from origin

participant Browser
participant DNS
participant CDN
participant Origin

Browser -> DNS : resolve
DNS --> Browser : address

Browser -> CDN : GET /page
activate CDN

alt cached {
    CDN --> Browser : 200 OK (cached)
}
else {
    CDN -> Origin : GET /page
    activate Origin
    Origin --> CDN : 200 OK
    deactivate Origin
    CDN --> Browser : 200 OK
}

deactivate CDN
