International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / The Consultative Committee for Space Data Systems (CCSDS) developed the CCSDS File Delivery Protocol (CFDP) to provide reliable delivery of files across space links. Space links are typically intermittent, requiring flexibility on the part of CFDP. Some aspects of that flexibility will be highlighted in this paper, which discusses the planned use of CFDP on the Global Precipitation Measurement (GPM) mission. The operational scenario for GPM involves reliable downlink of science data files at a high datarate (approximately 4 megabits per second) over a space link that is not only intermittent, but also one-way most of the time. This paper will describe how that scenario is easily handled by CFDP, despite the fact that reliable delivery requires a feedback loop.

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Reliable delivery of data products is often required across space links. For example, a NASA mission will require reliable delivery of images produced by an on-board detector. Many missions have their own (unique) way of accomplishing this, requiring custom software. Many missions also require manual operations (e.g. the telemetry receiver software keeps track of what data is missing, and a person manually inputs the appropriate commands to request retransmissions). The Consultative Committee for Space Data Systems (CCSDS) developed the CCSDS File Delivery Protocol (CFDP) specifically for this situation. CFDP is an international standard communication protocol that provides reliable delivery of data products. It is designed for use across space links. It will work well if run over the widely used CCSDS Telemetry and Telecommand protocols. However, it can be run over any protocol, and will work well as long as the underlying protocol delivers a reasonable portion of the data. The CFDP receiver will autonomously determine what data is missing, and request retransmissions as needed. The CFDP sender will autonomously perform the requested transmissions. When the entire data product is delivered, the CFDP receiver will let the CFDP sender know that the transaction has completed successfully. The result is that custom software becomes standard, and manual operations become autonomous. This paper will consider various ways of achieving reliable file delivery, explain why CFDP is the optimal choice for use over space links, explain how the core protocol works, and give some guidance on how to best utilize CFDP within various mission scenarios. It will also touch on additional features of CFDP, as well as other uses for CFDP (e.g. the loading of on-board memory and tables).

Thesis (M.S. in Computer Science)--Naval Postgraduate School, March 2004. / Thesis advisor(s): Wen Su, John Gibson. Includes bibliographical references (p. 189). Also available online.

Thesis (M.Sc.(Computer Science))--University of Pretoria, 2000. / Summaries in Afrikaans and English.

No description available.

Överföring eller mottagande av datorfiler är en syssla som de flesta av oss ägnar ossåt regelbundet i ett eller annat sammanhang, oavsett om det sker privat eller om detär arbetsrelaterat. File Transfer Protocol (FTP) är ett protokoll för just detta ändamålsom lanserades under tiden då persondatorer hade blivit allt vanligare i hemmetoch på arbetsplatsen. Sedan dess har flera andra protokoll introducerats och i dagslägetfinns det flertalet valmöjligheter tillgängliga, alla med sina unika såväl som gemensammaegenskaper. Simple Mail Transfer Protocol (SMTP) kompletterad medMIME-standarden är ett populärt alternativ till de renodlade filöverföringsprotokollenpå grund av användarnas bekantskap och tidigare erfarenheter med e-posttjänster.Att skicka och ta emot filer via e-post innebär dock vissa begränsningar samt att vissasäkerhetsaspekter måste tas i beaktande, i synnerhet för företagsanvändare som dagin och dag ut måste hantera känslig data. I denna uppsats har tre olika filöverföringsprotokoll(SFTP, SMTP och HTTP) utvärderats ur ett användarvänlighetsperspektivsåväl som ett säkerhetsperspektiv. Resultatet indikerar att HTTP(S) tillsammans meduttökningen WebDAV kan anses vara ett lämpligt alternativ för organisationer somsamtidigt är enkelt att använda. De övriga protokollen, SMTP och SFTP, har ocksåsina användningsområden där SFTP verkar vara mer tilltalande för avanceradeanvändare och där SMTP förblir ett gångbart alternativ för privat bruk av mindreavancerade användare under vissa förutsättningar. / Transferring and receiving computer files are something most of us do on a regularbasis whether it is for private purposes or if it is work related. FTP is a protocolused for this very purpose which was launched during a time when personal computerswere growing increasingly popular in both home and workplace environments.Since then, more protocols have been introduced and today there are a number ofoptions available bringing new and common features alike to the market. The SMTPprotocol, extended with the MIME standard, is currently a widely used alternative tothe pure file transfer protocols due to the user familiarity and past experiences withthese mail services. Sending and receiving files through e-mail does however implysome limitations together with the fact that some security aspects need to be takeninto consideration, particularly for company users handling sensitive data. In thisthesis, three different file transfer protocols (SMTP, SFTP and HTTP) have all beenevaluated in account of their user friendliness as well as their security features. Theresults indicate that HTTP(S) combined with the WebDAV extension can be considereda viable alternative for organizations due to its user friendliness and security.The remaining protocols, SMTP and SFTP, also have their uses where SFTP wouldseem to be an appealing option for advanced users and where SMTP remains a passablealternative for private usage by regular users under the right conditions.

This master thesis is mainly focused on the backup systems and describes each individual backup techniques in detail. Next main point of this thesis, is explaining functionality of IPv4 and FTP, which are closely related to the topic. Outcome is a backup application written in Java language, which is capable of backup files on FTP server or on local/ network storage area. Backup application also allows settings for automatic backup and restoring files from the storage area. Finally there was made a measurment, where were point out advantages and disadvantages of transfer mediums and where was practically shown a logic of creating the backup system. Goal was a creation of multiplatform backup application.

Approved for public release; distribution is unlimited / Special Forces are crucial in specific military operations. They usually operate in hostile territory where communications are difficult to establish and preserve, since the operations are often carried out in a remote environment and the communications need to be highly mobile. The delivery of information about the geographical parameters of the area can be crucial for the completion of their mission. But in that highly mobile environment, the connectivity of the established wireless networks (LANs) can be unstable and intermittently unavailable. Existing content transfer protocols are not adaptive to volatile network connectivity. If a physical connection is lost, any information or part of a file already retrieved is discarded and the same information must be retransmitted again after the reestablishment of the lost session. The intention of this Thesis is to develop a protocol in the application layer that preserves the already transmitted part of the file, and when the session is reestablished, the information server can continue sending the rest of the file to the requesting host. Further, if the same content is available from another server through a better route, the new server should be able to continue to serve the content, starting from where the session with the previous server ended. / Lieutenant, Hellenic Navy

by Pan Jiao Feng. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 89-93). / Abstract also in Chinese. / Abstract --- p.i / Acknowledgments --- p.v / List of Tables --- p.x / List of Figures --- p.xi / Chapter Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Graph definitions --- p.2 / Chapter 1.2 --- The S box graph --- p.2 / Chapter 1.3 --- The file transfer graph --- p.4 / Chapter 1.4 --- "(g, f)-factor and (g, f)-factorization" --- p.5 / Chapter 1.5 --- Thesis contributions --- p.6 / Chapter 1.6 --- Organization of the thesis --- p.7 / Chapter Chapter 2. --- On the Optimal Four-way Switch Box Routing Structures of FPGA Greedy Routing Architectures --- p.8 / Chapter 2.1 --- Introduction --- p.9 / Chapter 2.1.1 --- FPGA model and S box model --- p.9 / Chapter 2.1.2 --- FPGA routing --- p.10 / Chapter 2.1.3 --- Problem formulation --- p.10 / Chapter 2.2 --- Definitions and terminology --- p.12 / Chapter 2.2.1 --- General terminology --- p.12 / Chapter 2.2.2 --- Graph definitions --- p.15 / Chapter 2.2.3 --- The S box graph --- p.15 / Chapter 2.3 --- Properties of the S box graph and side-to-side graphs --- p.16 / Chapter 2.3.1 --- On the properties of the S box graph --- p.16 / Chapter 2.3.2 --- The properties of side-to-side graphs --- p.19 / Chapter 2.4 --- Conversion of the four-way FPGA routing problem --- p.23 / Chapter 2.4.1 --- Conversion of the S box model --- p.24 / Chapter 2.4.2 --- Conversion of the DAAA model --- p.26 / Chapter 2.4.3 --- Conversion of the DADA model --- p.27 / Chapter 2.4.4 --- Conversion of the DDDA model --- p.28 / Chapter 2.5 --- Low bounds of routing switches --- p.28 / Chapter 2.5.1 --- The lower bound of the DAAA model --- p.29 / Chapter 2.5.2 --- The lower bound of the DADA model --- p.30 / Chapter 2.5.3 --- The lower bound of the DDDA model --- p.31 / Chapter 2.6 --- Optimal structure of one-side predetermined four-way FPGA routing --- p.32 / Chapter 2.7 --- Optimal structures of two-side and three-side predetermined four-way FPGA routing --- p.45 / Chapter 2.7.1 --- Optimal structure of two-side predetermined four-way FPGA routing --- p.46 / Chapter 2.7.2 --- Optimal structure of three-side predetermined four-way FPGA routing --- p.47 / Chapter 2.8 --- Conclusion --- p.49 / Appendix --- p.50 / Chapter Chapter 3. --- "Application of (0, f)-Factorization on the Scheduling of File Transfers" --- p.53 / Chapter 3.1 --- Introduction --- p.53 / Chapter 3.1.1 --- "(0,f)-factorization" --- p.54 / Chapter 3.1.2 --- File transfer model and its graph --- p.54 / Chapter 3.1.3 --- Previous results --- p.56 / Chapter 3.1.4 --- Our results and outline of the chapter --- p.56 / Chapter 3.2 --- NP-completeness --- p.57 / Chapter 3.3 --- Some lemmas --- p.58 / Chapter 3.4 --- Bounds of file transfer graphs --- p.59 / Chapter 3.5 --- Comparison --- p.62 / Chapter 3.6 --- Conclusion --- p.68 / Chapter Chapter 4. --- "Decomposition Graphs into (g,f)-Factors" --- p.69 / Chapter 4.1 --- Introduction --- p.69 / Chapter 4.1.1 --- "(g,f)-factors and (g,f)-factorizations" --- p.69 / Chapter 4.1.2 --- Previous work --- p.70 / Chapter 4.1.3 --- Our results --- p.72 / Chapter 4.2 --- Proof of Theorem 2 --- p.73 / Chapter 4.3 --- Proof of Theorem 3 --- p.79 / Chapter 4.4 --- Proof of Theorem 4 --- p.80 / Chapter 4.5 --- Related previous results --- p.82 / Chapter 4.6 --- Conclusion --- p.84 / Chapter Chapter 5. --- Conclusion --- p.85 / Chapter 5.1 --- About graph-based approaches --- p.85 / Chapter 5.2 --- FPGA routing --- p.87 / Chapter 5.3 --- The scheduling of file transfer --- p.88 / Bibliography --- p.89 / Vita --- p.94

Cloud computing is pervasive in our daily life. For instance, I usually use Google¡¦s GMail to receive e-mail, Google Document to edit documents online and Google Calendar to make my daily schedule. We can say that Google provides a ¡§Platform as a Service (PaaS)¡¨, which delivers a computing platform as a service, and the platform sustaining lots of cloud applications such as I mentioned above. However, the cloud computing platform of Google is private: we cannot trace its source code and make cloud applications on it! Fortunately, there¡¦s an open source project supported by Apache named ¡§Hadoop¡¨, which has a distributed file system which is very like Google File System (GFS) called ¡§Hadoop distributed file system (HDFS)¡¨. In order to observe the properties of HDFS, we design and implement a HDFS-based FTP server system called FTP-ON-HDFS system, say, a FTP server whose storage is HDFS. There are a web-console for FTP administrator, a FreeRADIUS server and a MySQL database for user authentication, a NameNode daemon on its machine, a SecondaryNameNode on its machine and five DataNode daemons and on five different machines in FTP-ON-HDFS system. Our FTP-ON-HDFS system can tune two QoS parameters: ¡§data block size¡¨ and ¡§data replication¡¨. Then, we tuned ¡§data block size¡¨ and ¡§data replication¡¨ in our system and compared its performance with Hadoop File System (FS) shell command and normal vsftpd. On the other hand, FUSE can mount HDFS from remote cluster to local machine, and make use of the permission of the local machine to manage HDFS. So, we compared the performance of FUSE with HDFS (FUSE-DFS) and our FTP-ON-HDFS system.