Introduction, Basic principles, The tandberg api engine – TANDBERG 6000MXP User Manual
Page 40: Structuring of information, Addressing using xpath or tandberg simplepath, Feedback
40
D 13887.08
MAY 2008
TANDBERG 3000
MXP
&
6000
MXP
REFERENCE GUIDE FOR SYSTEM INTEGRATORS
Introduction
About the TANDBERG API
The heart of the API is the TANDBERG
API-Engine. This is where all information is
stored and processed. The API-engine can
be accessed by an easy-to-use Command
Line Interface called
XACLI
using RS 232
or Telnet, or by the TANDBERG XML API
Service (TXAS) over HTTP/HTTPS.
API-Engine
XACLI
TXAS
RS 232
Telnet
HTTP
HTTPS
Working with the API-engine is very similar
to working with catalogues and files on a
computer. All information is stored in a hi-
erarchic tree structure which is accessible
from different interfaces.
When accessing the API-engine using
XACLI
(RS 232 or Telnet), the information
is formatted in a proprietary Command Line
style or in XML formatting.
When accessing the API-engine using the
TXAS
interface (HTTP/HTTPS), XML/SOAP
formatting is supported.
This is similar to viewing files on a compu-
ter; accessing catalogues on a Windows
computer using the Command Prompt
gives a different view than using Windows
Explorer, but the information is the same.
NOTE!
New features on the TANDBERG
MXP
will be supported on XACLI only.
Basic Principles
The TANDBERG API Engine
The TANDBERG API-Engine is optimized for easy, yet advanced, machine-
machine interaction between a TANDBERG system and an external control
application.
The main features can be summarized to:
Structuring of information
•
Addressing using XPath (XML Path Language) or TANDBERG SimplePath
•
Feedback
•
Structuring of Information
An application programming interface (API) can be seen as a gate where infor-
mation is exchanged between two systems – a control application and a target
system.
The control application transmits instructions to the target system, while the
target system supplies information about how these instructions are executed,
in addition to other system related information.
Consequently, the exchange of information can be divided into:
Information flowing
1.
from target. This we call
READ
information
(R)
. The (
R
)
should not be confused with the (
r
) used to indicate required parameters in
the Commands tables.
Information flowing
2.
to target. This we call
WRITE
information
(
W
)
.
If we now look at the TANDBERG systems we can identify three main types of
information
READ
•
information
(R)
WRITE
•
information
(W)
READ-WRITE
•
information
(RW)
(R) READ
information. This is Status Information about the system and system
processes, i.e. information generated by the system.
Typical examples include: status about ongoing calls, network status, confer-
ence status etc.
All status information is structured in a hierarchy, making up a database con-
stantly being updated by the system to reflect process changes.
(W) WRITE
information. This is Command Information the user/control applica-
tion supply to initiate an action.
Typical examples include: instructing the system to place a call, assigning floor
to a specific site, disconnecting a call etc.
A command is usually followed by a set of parameters to specify how the given
action is to be executed.
(RW) READ-WRITE
information. This is Configuration Information defining sys-
tem settings. This information can both be supplied and read by the user/con-
trol application. Typical examples include: default call rate, baud rate of a serial
port, enabling/disabling of various features etc.
All configuration information is structured in a hierarchy making up a database
of system settings. But for the Configuration information, the data in the data-
base can only be updated by the user/control application.
Addressing Using XPath or TANDBERG SimplePath
To address information in the hierarchic structure of Status and Configuration
information, the TANDBERG systems support abbreviated XML Path Language
(XPath) and a proprietary notation called TANDBERG SimplePath (only available
using XACLI).
This allows the user/control application to address everything from a single
element of data (for example the call rate of a specific call) to larger parts of the
hierarchy (for example all information available for a given call).
Feedback
Feedback is an extremely powerful feature where the TANDBERG system
actively returns updated status and configuration information to the user/
control application whenever changes occur.
The user/control application can specify what parts of the status and configura-
tion hierarchies it wants to monitor by using XPath. The user/control application
can thereby limit the amount of information it receives from the target system to
only those parts being of interest for the given application. This will also reduce
the load on the link connecting the systems.
Feedback is supported on both XACLI (RS232/Telnet) and TXAS (HTTP/
HTTPS) simultaneously.
The system uses TANDBERG SimplePath when presenting configurations.
are described more thoroughly later in this
section of the manual.
The structuring of information together with XPath and TANDBERG SimplePath
for addressing, makes up powerful features like searchability and setting of
multiple instances of a configuration.
Examples are provided overleaf.