Internet Protocols.

Data blocks in the FTP protocol are transferred in the order of increasing file offset relying on the reliability of TCP. Marker blocks allow a transmission to be restarted, when a major system failure occurs [32]. A more generic support for sequential transfer of objects over reliable transfer protocols is provided by HTTP [22]. File exchange facilities over P2P networks build FTP-like services upon advanced file indexing/routing functionality [37]. Raman et al. improve the interactive transfer of images over the Internet by delivering data to the client as they arrive, thus removing the in-order abstraction embedded in TCP [34]. Diot and Gagnon examine network transmission benefits in out-of-sequence processing of packets [19]. However, neither the applications that they study include large file delivery, nor they consider interactions with the storage devices. Recent P2P file sharing facilities allow a client to concurrently download different parts of a file from multiple servers [17]. In such cases, data reordering on each server can benefit the efficiency of the system when the served file segments are sufficiently large, especially with resource-constrained nodes.