webpointmorpheus Network Info
Network Operating Systems

     Overview      NOS Defined      Microsoft      Novell      Unix/Linux      Apple

©2005 - material compiled by Bob Carnaghi, www.webpointmorpheus.com

Overview     Top of Page

Network Operating Systems are the 'brand names' or overall packages which encompass one or more of a hybrid of network access protocols. An example comparison is the automobile industry. There are several auto manufacturers: Chrysler, Ford, Chevrolet, etc. Some of these types use their own proprietary engines, some use an engine made by another manufacturer. At this point in time, a Chevrolet Tracker will come with a Subaru engine that's assembled in Japan. Network Operating Systems work the same way. Novell Netware versions 3.x and 4.x used the proprietary IPX/SPX protocol suite. Version 5 of Novell Netware embraced TCP/IP due to its popularity. Understanding Network Operating Systems begs understanding the difference between protocols, protocol suites, and manufacturing companies.

If you have a difficult time with the acronymn drenched terms used in this document, check out the Network Definitions Page.

NOS Defined     Top of Page

Server: A server is a dedicated computer system that runs specialized software programs to provide clients access to certain resources. Their typical purpose is to provide these services, and servers do not usually have user software installed.

Client: Description of networked computer that requests services from a Server.

Client/Server: Description of network architecture that has a dedicated server installed.

Peer to Peer: A small network where any single host on the network can act as Server or Client.

Microsoft     Top of Page

Microsoft has several NOS's available, depending on the needs of the network. NetBEUI works on small networks that are running Windows 9x and Windows NT. NetBEUI will work as well on Windows 2000 and XP, however in NetBEUI cannot fulfill the security and other needs demanded by larger networks that serve many (more than 25-30) nodes.

Windows 2000 Server and Windows XP Server create domains which can be scaled for larger networks. These NOS's use active directory, DHCP, and other services to fulfill the needs of a corporate LAN. These network environments typically have up to several hundred nodes spread across several domains.

Novell     Top of Page

Novell Netware is the NOS which historically used IPX/SPX. Netware employs Netware Directory Services (NDS), which allows network resources to be grouped together and organized in a hierarchical way. NetWare systems prior to NetWare 4 relied on the a database which was called the bindery. The bindery relied heavily on SAP (Service Advertising Protocol). NetWare version 5 has embraced TCP/IP, which makes it fully compatible with other operating systems that use TCP/IP.

Unix/Linux     Top of Page

UNIX is a multi-tasking, multi-user, command line operating system. UNIX uses 'dumb' terminals that are connected to a centralized server. The terminal monitors and keyboards serve as input devices to the 'main-frame' computer. Clients often use a terminal emulator (TELNET) or other specialized software to access the server. TCP/IP is the native protocol in UNIX networks. The HOSTS file and DNS originated on UNIX.

The NFS (Network File System) is an important part of UNIX networking which allows a UNIX machine to mount a directory (share) that is on a remote computer. The remote file system can be treated as if it is part of the local file system. The NFS has security drawbacks. SAMBA is a UNIX service that was developed to provide SMB (Service Message Block) communication between Windows and UNIX. SMB is similar to NFS, and is used primarily on Windows NT networks. Unix uses a LPD (Line Printer Daemon) as the print server, with the LPR (Line Printer Remote) as the client.

   Linux

Linux is an open source operating system that is based on UNIX. Linux was originally developed by Linus Torvalds as an educational project in response to the demands of the costly UNIX OS. Linux has remained open source since it was first released in the 1990's. There have been many extensions, utilities, GUIs, and other software applications contributed by individual programmers through the open source community. Due to the GPL (Gnu Public License) agreement, there are many different distributions of Linux developed, several of which are free. Approximately 60% of the web servers on the Internet today operate under the Linux operating system, with other open source software such as Apache, MySQL database, etc. Besides serving as an HTTP, FTP, or mail server, Linux is also often used for firewalls and proxy servers with SQUID, as well as file servers using SAMBA. Linux can accommodate 386 processor architecture, and can run server software as well as workstation applications. Although Linux shines as a server OS, there are several GUIs available which make it user-friendly for the individual user.

Apple     Top of Page

AppleTalk is the native Macintosh file and printer sharing and mail NOS. As with the nomenclature used in most other computers, a Mac that shares resources is called a server, and the computer connecting to it a client. Similar to the TCP/IP protocol suite, AppleTalk is not a single protocol, but a suite of several protocols which serve various functions. AppleTalk is built into all Macintosh computes, and typically works transparently to the user. AppleTalk is defined similarly to the 7-layer OSI model.

The Physical and Data Link layers define that allow AppleTalk to run on different media-access technologies. EtherTalk allows AppleTalk to run over Ethernet, TokenTalk allows AppleTalk to run over Token Ring, FDDITalk allows AppleTalk to run over FDDI, and LocalTalk is Apple's proprietary media-access technology, which is capable of CSMA/CA. LocalTalk uses UTP or STP cabling and has a maximum data transfer rate of 230 Kbps. This topology is alive and well today,typically in small SOHO environments.