Siemens V4.0 manual Introduction to NetBIOS, Configuring NetBIOS, NetBIOS Names

Configuring Advanced Server for UNIX Configuring NetBIOS

5.1.1 Introduction to NetBIOS

An important part of Advanced Server for UNIX communication is not based directly 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 unique 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 establishing, 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 drivers 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 Server 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 converted to uppercase letters and padded with spaces), but reserve the 16th character of the NetBIOS name to indicate a resource type (00-FF hex). Names can be registered as unique (one owner) or as group (multiple owner) names. In addition to this there is also the concept 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]	Workstation Service
<computername>[0x03]	Messenger Service
<computername>[0x20]	Server Service
<username>[0x03]	Messenger Service
<domain_name>[0x1D]	Master Browser
<domain_name>[0x1B]	Domain Master Browser (PDC)

Product Manual U7613-J-Z815-6-76