Cisco Networking: NetBIOS Extended User Interface
The use of Network Basic Input/Output System (NetBIOS) occurs at the session layer — not the network layer. This has caused a lot of confusion for many people because NetBIOS is sometimes used — incorrectly — as a synonym for NetBIOS Extended User Interface (NetBEUI), which is a distinct network protocol that is built heavily around NetBIOS.
Microsoft uses NetBIOS heavily as a session layer protocol. As such, Microsoft also adopted NetBEUI as its default protocol for its operating systems.
Compared to IPX and IP, one of the major shortcomings of NetBEUI is that it is not a routable protocol. You cannot create a large multisite network using NetBEUI because you cannot route traffic between locations. You could set up a multisite bridged network, but even that causes a lot of unneeded traffic to cross the links between your offices or locations.
This is not desirable. The address that is used to identify stations on a NetBEUI-based network is the MAC address of each station on the network. Your network devices will not have a network portion of their address like IPX and IP included with their addresses.