A network that uses multiple network architectures and operating systems. An example of a heterogeneous network at the hardware level is a combination of Ethernet and Token Ring local area networks (LANs) connected with a Fiber Distributed Data Interface (FDDI) backbone.
An example at the network operating system (NOS) level is a server room in which some machines are running Microsoft Windows NT, others are running UNIX, and still others are running Novell NetWare. An example at the application level is a messaging system that includes Microsoft Exchange Server, Novell GroupWise, UNIX Sendmail, and IBM PROFS mail systems.
Heterogeneous networks are generally more complex to administer than homogeneous networks. Most networks are heterogeneous because they evolve over a period of time. Most startup companies cannot afford to buy a completely homogeneous, state-of-the-art network platform, and even if they could, it would soon become out of date.
One advantage of deliberately maintaining a heterogeneous network is that customers can use any product they choose instead of being locked into a single vendor’s system. Networking and operating system choices can be made on a “best-served” basis instead of an “only buy from us” approach.