The "Hands-On Internet for Business" Workshop

Internet Server Applications (DAEMONs)

There are many Internet server applications. The most commonly used Internet server applications are the finger servers, the mail servers, the Telnet/FTP/WWW servers, the NFS server, and the gopher server.

finger servers

mail servers

Telnet/FTP/WWW servers

NFS server

gopher server

Finger Server (DAEMON)

The finger server, on most systems, waits for user information requests. If the request does not specify an user, this server transmit, to the requestor, the list of users who are currently logged on, assorted status of those users, and the contents of those users' "plan" file and "project" files (both are text files whose contents the users generated). If the request does specify an user, the server transmits, to the requestor, the previously mentioned information about the user regardless of whether the user is currently logged on or not. Tidewater Systems developed a MS-Windows version of the finger server which transmits the contents of the "plan" file when requested. It is available at the University of Maryland FTP server:

ftp site:     sparky.umd.edu

directory:    /pub/winsock

file names:   wfngrd13.zip*
              (Windows Finger DAEMON version 1.3)

*Use PKZIP to decompress this file. It can be found at the FTP site of the National Center for Supercomputing Applications:

ftp site:     ftp.ncsa.uiuc.edu

directory:    /PC/Contrib

file names:   pkzip204g.exe

Mail Server (DAEMON)

The mail server waits for incoming mail messages and requests to access mail messages. When an incoming mail message arrives, the server accepts the message, if the message is bound for another node, the mail server hands it off to the appropriate node. If the message is bound for the node on which the server is running, the server stores the message into the mail box specified in the message. Most Internet application suites are packated with a mail server. The Chameleon Sampler application suite from Netmanage includes a mail server.

Telnet/FTP/WWW Servers (DAEMON)

The Telnet/FTP/WWW servers waits for directory listing requests, change default directory requests, file transfer requests, and other operating system command line requests. If the request is allowable, the server executes the requested command. There are small differences between the three server applications. Telnet servers support all operating system commands with the exception of the file transfer functions. File Transfer Protocol (FTP) Servers only support directory listing requests, change default directory requests, and file transfer requests. WWW servers specialized FTP servers for supporting the HyperText Transfer Protocol. These server applications allow geographically distributed computers to share files and other processing resources.

Telnet Server

Telnet servers are usually available for operating systems with command line user interfaces. Since MS-Windows's user interface is a graphic interface, a telnet server for MS-Windows does not make much sense.

FTP Server

Although a FTP server is packaged with Netmanage Chameleon, Chameleon NFS, and Internet Chameleon, the FTP server is missing from the Chameleon Sampler. However, shareware implementations of FTP servers are available. One may be found at the University of Maryland FTP site.

ftp site:     sparky.umd.edu

directory:    /pub/winsock

file names:   wftpd19c.zip*
              (Windows FTP DAEMON, version 1.9c)

*Use PKZIP to decompress this file.

World Wide Web (WWW) Server (DAEMON)

The three most populer WWW servers for MS-Windows are SerWeb, Web4Ham, and WHTTPD. All three are freeware.

SerWeb is the easiest to use. The directory for its executable code and the directory for its hypertext markup language files may be anywhere withing the hard disk's directory tree. However, it does not support indexed images and CGI forms.

Web4Ham is the second easiest to use. The directory for its executable code and the directory for its hypertext markup language files may also be anywhere withing the hard disk's directory tree. Web4Ham, however, supports indexed images and CGI forms.

Win-HTTPD is the most powerful and supports visual basic routines. But the price is a more complicated setup. The directory for its executable code must be a top-level directory. And its hypertext markup language files must be in the same directory as its executable code.

All three WWW servers may be found at the University of Maryland FTP site.

ftp site:     sparky.umd.edu

directory:    /pub/winsock

file names:   serweb03.zip*
              (Server Web, version 3.0)
              web4ham.zip*
              (Web for Hamburg, DBR, version 0.17)
              whttpd13.zip*
              (Windows HTTP DAEMON, version 1.3)

*Use PKZIP to decompress these files.

NFS Server (DAEMON)

The Network File Service (NFS) server application is very similar to the FTP server. Both allow remote nodes to access files on the host node. The difference between the two server is the access method. With FTP, the requested file is copied to the remote node resulting in to copies of the file. With the NFS, the requested file remains on the host node. The NFS client node view the NFS hard drive on the host node as a local drive.

Gopher Server (DAEMON)

The gopher server is also very similar to the FTP server. However, gopher clients do not use directory names to navigate the directory tree. Gopher clients also do not use file name to identify the location of the desired data. Gopher servers maintain a database of directory and file names with their associated natural language description. Gopher servers allow the gopher clients to search the database using the natural language description to identify the desired data.