Created: 1999 July 28
Revised: 2008 February 19
What Is WINS?
WINS (Windows Internet Name Service) is Microsoft's NetBIOS name resolution
service running on Windows platforms. You can think of WINS as a way to
provide Domain Name System (DNS) functionality in a NetBIOS world.
NetBIOS B-node (broadcast) traffic consumes a fair amount of bandwidth on
networks. To minimize NetBIOS traffic, Microsoft created NBNS (NetBIOS Name
Server) as a solution, dubbing it WINS.
With WINS, network broadcasts are sent directly to the WINS server instead of
to every machine in the broadcast domain.
WINS gives Windows devices that use TCP/IP a way to resolve simple machine
names to IP addresses. But WINS also provides the NetBIOS functions associated
with that machine name. WINS accomplishes this resolution through the use of
the 16th-byte value. The 16th-byte value is, as its name implies, a byte of
information that WINS tacks on to the end of every NetBIOS machine name in
a Windows environment. This placement means that Windows machine names
cannot exceed 15 bytes, and the 16th byte is reserved for this special value.
You don't ordinarily see the 16th-byte value when you refer to Windows
machines by name. However, you can see evidence of the 16th byte if you open
up a command shell on your computer and type the command:
nbtstat -n
Why Use WINS?
Other than reducing overall network traffic, the use of WINS
also effectively promotes faster name resolution speed (i.e. faster
browsing from your computer to others).
How Does It Work?
Each time a WINS client device starts up, it registers its
NetBIOS name and IP address with the WINS server.
When a WINS client
initiates a command to communicate with another host, the resulting
name-query request is sent directly to the WINS server instead of being
broadcast all over the network.
If the WINS server finds the
destination host's NetBIOS name and current IP address mapping in its
database, it returns this information to the WINS client.
For
further information on NetBIOS-over-TCP/UDP and WINS, check the following
links:
