Netspeak

Manufacturing Engineering, Mar 1998

Jeffrey Simon of Migration Software provides this users' guide to the Net's alphabet soup of technologies. Start with the basic protocol used for most communication over the Internet: it's called TCP/IP (Transmission Control Protocol/Internet Protocol). TCP identifies information packets and error-checks information transfers. IP is the Internet's information transmission protocol. Together, they let computers differentiate messages received from the Net. The oldest protocol for downloading software and large files is FTP (File Transfer Protocol). For mail, there's SMTP (Standard Mail Transport Protocol).

Every Web page has a pointer, or URL (Universal Resource Locator). Every Web server has a URL host address tied to a TCP/IP unique designator. A government-run Internet center assigns and tracks all those dotcoms, dot-orgs, dot-govs, dotedus, dot-frs, and dot-des. DNS servers translate URLs into an IP address. Web addresses decode as transfer format (http, ftp, gopher, news, Idap, or file), followed by ://, then host name and path information.

Browsers get you there, and they don't care what machine or operating system you're using. Plug-ins, the key to moving CAD files around, are small programs run with a browser, usually developed by third-party vendors and downloaded to a client from a Web site or from a diskette or CDROM. They let you handle proprietary CAD formats and vector or 3-D graphic formats.

Standard file languages are HTML, or Hypertext Markup Language, which formats documents for the browser, merging text, graphics, forms, and the range of Web materials over a TCP/IP.

For solid models, VRML, or Virtual Reality Modeling Language, allows users to create 3-D worlds and navigate through them on the Web with ease; it is platform-independent, works with low-bandwidth network connections, and can be extended.

Protocols include SVF (Simple Vector Format), a simple format for describing vector images including points, lines, circles, Bezier curves, and text-supporting layers, hypertext, fill changes, and notifications. CGM (Computer Graphics Metafile) contains encoded graphics instructions. TIFF (Tag Image File Format) is a raster imaging format used with scanned documents and electronic document management systems.

The standard Web format for displaying images is GIF (Graphic Interchange Format); to show photos, it's JPEG (Joint Photographic Experts Group). Nowadays Net surfers use PDF (Portable Document Metafile) to download publications.