A system, a method and a computer program product for transmission over a network, the method includes: receiving, by an intermediate system coupled to the network, a portion of a data structure that is aimed to a recipient computer; generating a stamp that is responsive to a content of a segment of the data structure and is indifferent to transfer information about a transmission of the data structure; wherein the portion may include the segment or equals the segment; determining, by the intermediate system, whether to cache the portion, in response to at least a comparison between the stamp and stamps of cached portions of data structures; selectively caching the portion in response to the determination; and transmitting to the recipient computer either one of the portion of the transmitted data structure and a cached version of the portion of the transmitted data structure.