UNIX Based System Software
Basic system Name Server
2. Basic system Name Server (BNS)
The Basic system Name Server (BNS) is a facility to provide a mapping
from a set of names to a set of corresponding items.
Some definitions of names
: piece of information identified with a logical name, which can be
either a symbol or an alias.
: logical name for an item used to obtain or modify the
corresponding item. BNS is case sensitive in handling symbols.
: kind of nickname for a symbol. An item can be obtained using
the symbol or using the alias of a symbol. An alias may never refer to
another alias. BNS is case sensitive in handling aliases.
3. BNS : Indirection Level
4. BNS : Concepts
Two types of aliases and symbols are known by BNS:
Local aliases and symbols only known on the local node. They are not
distributed to other nodes.
Global aliases and symbols distributed to other nodes (by mean of
CDC). A global alias may not reference a local symbol. A local alias
may, however, reference a global symbol.
BNS is used by several UBSS services :
 IPC/FIFO services for the mapping of address,
 IOC_LPR_SERVER for logical names of printers,
 SCM for applicative state of the node.
BNS provides services for application processes.
5. BNS : model
Logique Name Logical or Physical Attributes
FIFO FPL 188.8.131.52 :: 109 :: TCP
6. BNS : Configuration
NODE 1 NODE 2 NODE 3
BNS BNS BNS
store store store
7. BNS : functionalities
The Basic system Name Server performs the following functions:
Pre-processing of the Name Server File (NSF), which contains local
and global symbols and local and global aliases. The syntax and
semantics of the NSF contents are checked. BNS exits when an error is
detected in the NSF.
Creates a local database containing the names specified in the NSF and
the global names received from other nodes.
Distributes initialized, modified and deleted global symbols and aliases.
Maintains the local BNS database.
Executes the requests issued by applications by means of the BNS
Notifies applications when names or aliases are initialized, modified or
Executes the BNS specific commands of BNSIO.
8. BNS : Change Notification
Alias SYMBOL ITEM
Attributs Change Notification
Alias Change Notification to FIFO
The Name Server File (NSF) :
initialization file for BNS which defines all symbols and aliases.
used to fill the BNS database. In this file only a part of the filling of
the local database is specified, since the local BNS database is also
filled with global symbols and aliases which were inserted at remote
It is impossible for application programs to insert new symbols or
aliases in the BNS database dynamically
BNSIO is a tool for an interactive user to inspect, modify or delete symbol
or aliases known by BNS.
10. BNS library functions
Retrieve name or alias
Retrieve the corresponding item of a specified name.
Retrieve the corresponding symbol of a specified alias.
Modify name or alias
Modify the item of a specified name.
Modify the symbol of a specified alias.
Enable/disable notification relative to creation,modification
and deletion of a specified name.
Enable/disable notification relative to creation, modification
and deletion of a specified alias.
 Control BNS behavior
Control or retrieve BNS behavior
( [dis]connection from its network access ).