Gateway Supported Transmission Protocols

The Gateway supports multiple transmission protocols for the exchange of data and products. The currently predominant protocol for the dedicated circuits of the GTS are either X.25 or TCP/IP with Socket Streaming or X.25 over IP. The Gateway also supports FTP, e-mail, and HTTP for acquisition and dissemination higher level procedures, primarily for general Internet access. The implementation standard for X.25 and Socket Stream are detailed in the WMO document "Manual on the Global Telecommunication System" No. 386. The more commercial standard processes using FTP, HTTP, and SMTP are not documented here other than by their use in data exchange procedures.

The transmission backbone protocols are:

• GTS (none IP based) point-to-point circuits use X.25
• GTS (IP based) dedicated circuits use TCP/IP/FTP, Socket Stream and in some cases X.25 over IP
• Standard TCP/IP higher level services use:
  • HTTP (web services)
  • FTP (file exchange services)
  • SMTP (e-mail services)
  • LDM [Local Data Manager](CONDUIT)
  • DBnet (NCEP local system)

The Gateway has implemented several higher level applications for several input and retrieval data exchange processes. The Gateway supports HTTP, FTP, and SMTP. The HTTP is used for WEB Page fill in forms to permit the delivery of WMO formatted bulletins. The FTP is used for FTP Input to permit the transmission of files containing WMO formatted bulletins for entry into the switching system. The Gateway also uses SMTP for FTPmail service used in allowing for retreival of server stored products from the Gateway file system. The use of HTTP and FTP are the predominant means for a user to use in accessing meteorological data and product stored on the center's file services. The LDM delivery system was designed by Unidata for large volume data delivery using server resources placed at designated universities. This higher level application is supported by Unidata for tailored use. The NCEP developed in-house DBnet is used for distribution of model products to designated government partners only. This is not supported for general use and requires NCEP setup.