Patent ID: 8078574

Claim:
A method comprising: storing a first version of content to a cache within an intermediate network device located between a first client device and a network server from which the content was obtained; receiving a request for the first version of the content; in response to the request, modifying the cache to include a token that references the first version of the content, wherein the token indicates that the first version of the content is not to be removed from the cache; reading the first version of the content from the cache based on the token; after reading the first version of the content from the cache, transmitting the first version of the content from the intermediate network device to the first client device; receiving a request with the intermediate network device for the content; determining whether a newer version of the content exists on a network server in response to the request; while transmitting the first version of the content, downloading a second version of the content with the intermediate network device from the network server based on the determination that the second version of the content is the newer version of the first version of the content; storing the second version the content with the intermediate network device to the cache while transmitting the first version of the content, wherein the first version of the content is a historical version of the second version of the content in that the second version of the content is a content update for the first version of the content; and transmitting the second version of the content from the intermediate network device to a second client device at least partially in parallel with the transmission of the first version from the intermediate network device to the first client device.