Abstract: Method for allowing peer-to-peer data transmission The invention relates to a method for allowing peer-to-peer data transmission between peer communication terminals. In this context, a file (D), for which multiple requests regarding retrieval have already been sent to an index server (IS) by peer communication terminals in the past, is automatically retrieved from a peer communication terminal (P3) providing this file by a storage peer communication terminal (SP). This file (D) is stored in the storage peer communication terminal (SP). The storage peer communication terminal (SP) registers as a provider of this file with the index server (IS). Upon receiving a further request relating to this file (D), the index server provides the requesting peer communication terminal with an address for the storage peer communication terminal in order to allow the requesting peer communication terminal to retrieve the file (D) from the storage peer communication terminal (SP).