416.htm

pcb设计资料初学者难得的入门资料包含工厂制作过程

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RFC 959                                                     October 1985 <br>
File Transfer Protocol <br>
      control connection <br>
         The communication path between the USER-PI and SERVER-PI for <br>
         the exchange of commands and replies.  This connection follows <br>
         the Telnet Protocol. <br>
      data connection <br>
         A full duplex connection over which data is transferred, in a <br>
         specified mode and type. The data transferred may be a part of <br>
         a file, an entire file or a number of files.  The path may be <br>
         between a server-DTP and a user-DTP, or between two <br>

         server-DTPs. <br>
      data port <br>
         The passive data transfer process "listens" on the data port <br>
         for a connection from the active transfer process in order to <br>
         open the data connection. <br>
      DTP <br>
         The data transfer process establishes and manages the data <br>
         connection.  The DTP can be passive or active. <br>
      End-of-Line <br>
         The end-of-line sequence defines the separation of printing <br>
         lines.  The sequence is Carriage Return, followed by Line Feed. <br>
      EOF <br>
         The end-of-file condition that defines the end of a file being <br>
         transferred. <br>
      EOR <br>
         The end-of-record condition that defines the end of a record <br>
         being transferred. <br>
      error recovery <br>
         A procedure that allows a user to recover from certain errors <br>
         such as failure of either host system or transfer process.  In <br>
         FTP, error recovery may involve restarting a file transfer at a <br>
         given checkpoint. <br>

Postel & Reynolds                                               [Page 4] <br>
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RFC 959                                                     October 1985 <br>
File Transfer Protocol <br>
      FTP commands <br>
         A set of commands that comprise the control information flowing <br>
         from the user-FTP to the server-FTP process. <br>
      file <br>
         An ordered set of computer data (including programs), of <br>
         arbitrary length, uniquely identified by a pathname. <br>
      mode <br>
         The mode in which data is to be transferred via the data <br>
         connection.  The mode defines the data format during transfer <br>
         including EOR and EOF.  The transfer modes defined in FTP are <br>
         described in the Section on Transmission Modes. <br>
      NVT <br>
         The Network Virtual Terminal as defined in the Telnet Protocol. <br>
      NVFS <br>
         The Network Virtual File System.  A concept which defines a <br>
         standard network file system with standard commands and <br>
         pathname conventions. <br>

      page <br>
         A file may be structured as a set of independent parts called <br>
         pages.  FTP supports the transmission of discontinuous files as <br>
         independent indexed pages. <br>
      pathname <br>
         Pathname is defined to be the character string which must be <br>
         input to a file system by a user in order to identify a file. <br>
         Pathname normally contains device and/or directory names, and <br>
         file name specification.  FTP does not yet specify a standard <br>
         pathname convention.  Each user must follow the file naming <br>
         conventions of the file systems involved in the transfer. <br>
      PI <br>
         The protocol interpreter.  The user and server sides of the <br>
         protocol have distinct roles implemented in a user-PI and a <br>
         server-PI. <br>
Postel & Reynolds                                               [Page 5] <br>
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RFC 959                                                     October 1985 <br>
File Transfer Protocol <br>
      record <br>
         A sequential file may be structured as a number of contiguous <br>

         parts called records.  Record structures are supported by FTP <br>
         but a file need not have record structure. <br>
      reply <br>
         A reply is an acknowledgment (positive or negative) sent from <br>
         server to user via the control connection in response to FTP <br>
         commands.  The general form of a reply is a completion code <br>
         (including error codes) followed by a text string.  The codes <br>
         are for use by programs and the text is usually intended for <br>
         human users. <br>
      server-DTP <br>
         The data transfer process, in its normal "active" state, <br>
         establishes the data connection with the "listening" data port. <br>
         It sets up parameters for transfer and storage, and transfers <br>
         data on command from its PI.  The DTP can be placed in a <br>
         "passive" state to listen for, rather than initiate a <br>
         connection on the data port. <br>
      server-FTP process <br>
         A process or set of processes which perform the function of <br>
         file transfer in cooperation with a user-FTP process and, <br>
         possibly, another server.  The functions consist of a protocol <br>
         interpreter (PI) and a data transfer process (DTP). <br>
      server-PI <br>

         The server protocol interpreter "listens" on Port L for a <br>
         connection from a user-PI and establishes a control <br>
         communication connection.  It receives standard FTP commands <br>
         from the user-PI, sends replies, and governs the server-DTP. <br>
      type <br>
         The data representation type used for data transfer and <br>
         storage.  Type implies certain transformations between the time <br>
         of data storage and data transfer.  The representation types <br>
         defined in FTP are described in the Section on Establishing <br>
         Data Connections. <br>
Postel & Reynolds                                               [Page 6] <br>
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RFC 959                                                     October 1985 <br>
File Transfer Protocol <br>
      user <br>
         A person or a process on behalf of a person wishing to obtain <br>
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-- <br>
指点江山，激扬文字，粪土当年万户侯。 <br>

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