The Service Database

The service database provides a way to associate arbitrary human-readable strings with the parameters needed to uniquely identify a particular protocol service. The strings are passed to lgo_Open() and lgo_Attach() to identify the service.

The default service database is service.db located in the cfg directory. This is a text file which can be edited with any text editor, such as the Windows editor notepad.

Each line in the service database has the following format:

<service> <protocol> <major device> <minor device> <cfg file>


The # character in the first column is the comment marker. Comments and blank lines are ignored.

The service names in the default database have the form:


For instance:

#	X.21 bis
PHYS0    4    0    0    null.cfg
PHYS1    4    1    0    null.cfg
PHYS2    4    2    0    null.cfg
PHYS3    4    3    0    null.cfg

LAPB0    5    0    0    null.cfg
LAPB1    5    1    0    null.cfg
LAPB2    5    2    0    null.cfg
LAPB3    5    3    0    null.cfg

#    X.25 Major Device with SVCs and 8 PVCs
PKT0     6    0    0    null.cfg
PVC01    7    0    1    null.cfg
PVC02    7    0    2    null.cfg
PVC03    7    0    3    null.cfg
PVC04    7    0    4    null.cfg
PVC05    7    0    5    null.cfg
PVC06    7    0    6    null.cfg
PVC07    7    0    7    null.cfg
PVC08    7    0    8    null.cfg

However, any strings can be used. For instance, for a connection to Dallas on physical line 0, you might name X.21 bis, HDLC LAPB and X.25 major device services DALLAS_X21, DALLAS_LAPB and DALLAS_X25. X.25 PVCs on that line might be designated DALLAS_1, DALLAS_2, etc. If the connection to Dallas later changes to line 3, only the service definitions need to be changed.

A single service definition may have multiple names. For instance, if physical line 0 is sometimes used for a connection to Dallas, sometimes for a connection to Paris, PARIS_X21, PARIS_LAPB and PARIS_X25 might be defined in the same way as DALLAS_X21, DALLAS_LAPB and DALLAS_X25. In this case, the connection to Paris could not be opened at the same time as the connection to Dallas.

Note: Use of the service database is optional (but recommended). The parameters associated with the service name can be passed directly as parameters to lgo_OpenProtocol() and lgo_AttachProtocol().