Configuring Advanced Server for UNIX Configuring NetBIOS
Product Manual U7613-J-Z815-6-76
© Siemens Nixdorf Informationssysteme AG 1995 Pfad: D:\O7613e6\u7613e.k05
5.1.1 Introduction to NetBIOS
An important part of Advanced Server for UNIX communication is not based di rectly on
TCP/IP protocols but uses NetBIOS.
In terms of the OSI Reference Model for a layered networking architecture, NetBIOS is a
level 5 protocol (“Session Layer ”). The session layer establishes a communications session
between processes running on different computers. Functions of the session layer include:
●Name Service: The Name Service allows application processes to register u nique
NetBIOS names. It provides the means by which these names can be resolved to the
network layer.
●Session Service: The Session Service is responsible for estab lishing, monitoring, and
terminating a virtual-circuit session between two processes identified by their NetBIOS
names.
●Datagram Service: This service allows application processes identified by their
NetBIOS names to exchange datagrams (messages of limited length).
On Advanced Server computers, NetBIOS services are provided by two STREAMS dri vers
which are linked to the UNIX kernel during NetBIOS installation.
NetBIOS Names
The NetBIOS name space is flat (that is, it is not hierarchical), so all names within a network
must be unique. NetBIOS names are 16 characters in length. Advanced S erver for UNIX
as well as Microsoft networking components allow the first 15 characters of a NetBIOS
name to be specified by the user or administrator (usually a given name is co nverted to
uppercase letters and padded with spaces), but reserve the 16th character of the NetBI OS
name to indicate a resource type (00-FF hex). Names can be registered as uniq ue (one
owner) or as group (multiple owner) names. In addition to this there is also the c oncept of
an internet group (with multiple owners and multiple addresses). Following are the important
NetBIOS names used in Advanced Server environments:
Unique names:
<computername>[0x00]
<computername>[0x03]
<computername>[0x20]
<username>[0x03]
<domain_name>[0x1D]
<domain_name>[0x1B]
Workstation Service
Messenger Service
Server Service
Messenger Service
Master Browser
Domain Master Browser (PDC)