Functions - AudioCodes Mediant 2000 User Manual

16.2.3

Functions

Functions - Define a certain procedure that can be activated in any state or in the
transition from one state to another. The available functions include, for example,
SET_TIMER (timer number, timeout in ms.) SEND_CAS (AB value, CD value). A full
list of the possible pre-defined functions can be found in the CASSetup.h file.
16.2.4 States
States - Each Protocol table consists of several states that it switches between during
the call setup and tear-down process. Every state definition begins with the prefix ST_
followed by the state name and colons. The body of the state is composed of up to 4
unconditional performed functions and list of actions that may trigger this state.
As an example, the table below was taken from an E&M wink start table protocol file:
Action
FUNCTION0
EV_TIMER_
EXPIRED2
EV_DIAL_
ENDED
When the state machine reaches the dial state, it sets timer number 2 and then waits
for one of the two possible actions to be triggered: either timer 2 expiration or end of
dial event. When timer 2 expires, the protocol table executes SEND_DEST_NUM
function and remains in the same state (NEXT_STATE=NO_STATE). When the dial
event ends, the protocol table sets timer 4 and moves to ST_DIAL_ENDED written in
the NEXT_STATE field.
Although users can define their own states, there are two states defined in the
CASSetup.h file and must appear in every protocol table created.
The two states are ST_INIT and ST_IDLE.
ST_INIT - When channels initialization is selected, the table enters the Init state.
This state contains functions that initialize the following global parameters:
•
•
•
User's Manual
Table 16-1: ST_DIAL: Table Elements
Function
#1
SET_TIMER 2
SEND_DES None
T_NUM
4
SET_TIMER
RC_IDLE_CAS - Defines the ABCD bits expected to be received in the IDLE
state in the specific protocol.
TX_IDLE_CAS - Defines the ABCD bits transmitted on IDLE state in the
specific protocol.
DIAL_PLAN - A change regarding the issue of an incoming call dialed
number is implemented in revision 3.21 as opposed to revision 3.2 and
earlier. In revision 3.2 and earlier, users were required to pre-define the
expected number of digit to receive an incoming call. If a lower number of
digits than expected were received, the call setup would have failed.
Parameter
#2
Extra Delay
Before Dial
None
No Answer Time
408
Mediant 2000
Next State
#3
None DO
None NO_STATE
None ST_DIAL_ENDED
Document # LTRT-69805