CASr1 scripting
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Revision as of 08:59, 30 July 2013 by Clod Patry (Talk | contribs)
CASR1 script summary
This script will be identified as a CASR1 script when the following
variable is set:
SCRIPT_TYPE="CASR1"
The CASR1 script allows implementation of all variants of CASR1 stacks
by controlling what actions must take place following received events.
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1. Overview
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The script will received an indication for each timeslot it has to
"control" through function HandleNewTimeslot.
The script will then be notified of any event on that timeslot
(CAS bits changes and others).
To each received event, the script will take one ore more action.
It's up to the script implementation to define it's own states
for handling the calls. The script is thus very flexible in the way
it implements the CASR1 variant call flow.
The current document does not describe how CASR1 call flows are
implemented (what are CAS bits, when and why to they "change",
how calling/called numbers are exchanged, what is the call flow etc.)
The reader shall find that information in the specifications for
CASR1 variants. This script should provide all tools required to
actually implement CASR1 variants.
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2. Configurable global script constants
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The script can define some constants required by the stack (though
default values are provided if the script does not define these
constants.
- SCRIPT_TYPE = "CASR1"
Defines the type of this sript. Must be CASR1 in current case.
- ABCD_PATTERN_MATCH_MASK = 0x1111
Mask to apply to CAS bits detected from remote equipment.
A bit which mask is set to 0 will be ignored and always reported as
zero (0) to this script.
This is useful in some cases when unused bits have undefined
(and even sometimes toggeling!) values.
- TONE_USE_DTMF = 1
Indicates the type of tones must be used to send/receive AND/DNIS.
Value of 1 stands for DTMF. Value of 0 defaults to MFR1.
DTMF mapping:
'0' -> DTMF Digit 0: 941Hz + 1336Hz
'1' -> DTMF Digit 1: 697Hz + 1209Hz
'2' -> DTMF Digit 2: 697Hz + 1336Hz
'3' -> DTMF Digit 3: 697Hz + 1477Hz
'4' -> DTMF Digit 4: 770Hz + 1209Hz
'5' -> DTMF Digit 5: 770Hz + 1336Hz
'6' -> DTMF Digit 6: 770Hz + 1477Hz
'7' -> DTMF Digit 7: 852Hz + 1209Hz
'8' -> DTMF Digit 8: 852Hz + 1336Hz
'9' -> DTMF Digit 9: 852Hz + 1477Hz
'*' -> DTMF Digit Star (*): 941Hz + 1209Hz
'#' -> DTMF Digit Pound (#): 941Hz + 1477Hz
'A' -> DTMF Digit A: 697Hz + 1633Hz
'B' -> DTMF Digit B: 770Hz + 1633Hz
'C' -> DTMF Digit C: 852Hz + 1633Hz
'D' -> DTMF Digit D: 941Hz + 1633Hz
Alternative values for * and #:
'E' -> DTMF Digit Star (*): 941Hz + 1209Hz
'F' -> DTMF Digit Pound (#): 941Hz + 1477Hz
MFR1 mapping:
'0' -> MFR1 Digit 0: 1300Hz + 1500Hz
'1' -> MFR1 Digit 1: 700Hz + 900Hz
'2' -> MFR1 Digit 2: 700Hz + 1100Hz
'3' -> MFR1 Digit 3: 900Hz + 1100Hz
'4' -> MFR1 Digit 4: 700Hz + 1300Hz
'5' -> MFR1 Digit 5: 900Hz + 1300Hz
'6' -> MFR1 Digit 6: 1100Hz + 1300Hz
'7' -> MFR1 Digit 7: 700Hz + 1500Hz
'8' -> MFR1 Digit 8: 900Hz + 1500Hz
'9' -> MFR1 Digit 9: 1100Hz + 1500Hz
'*' -> MFR1 KP (Start of pulsing): 1100Hz + 1700Hz
'#' -> MFR1 ST (End of pulsing): 1500Hz + 1700Hz
'A' -> MFR1 STI: 900Hz + 1700Hz
'B' -> MFR1 STII: 1300Hz + 1700Hz
'C' -> MFR1 STIII: 700Hz + 1700Hz
'D' -> Not supported in MFR1
Alternative characters:
'E' -> MFR1 KP (Start of pulsing): 1100Hz + 1700Hz
'F' -> MFR1 ST (End of pulsing): 1500Hz + 1700Hz
- TONE_ON_TIME = 60
Determines the "on time" (in ms) of tones used when sending ANI/DNIS.
- TONE_OFF_TIME = 50
Determines the "off time" (inter-digit delay)(in ms) of tones used
when sending ANI/DNIS.
- TONE_LEVEL = -10
Determines the level (in DB) of tones used when sending ANI/DNIS.
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3. Static constants pushed by the stack, for usage in this script
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Available actions for "StackAction" function:
Commonly used actions:
ACTION_END_SIGNALING
ACTION_SET_CAS_BITS
ACTION_SEND_WINK
ACTION_WAIT_WINK
ACTION_SEND_ANI
ACTION_SEND_DNIS
ACTION_WAIT_ANI
ACTION_WAIT_DNIS
ACTION_REPORT_SEIZURE
ACTION_REPORT_VALIDATE_CALL
ACTION_REPORT_ACCEPTED
ACTION_REPORT_ALERTED
ACTION_REPORT_ANSWERED
ACTION_REPORT_BLOCKED
ACTION_REPORT_UNBLOCKED
ACTION_START_TIMER
ACTION_CANCEL_TIMER
Additional actions to implement special variants
ACTION_SEND_TONE
ACTION_SET_ANI
ACTION_SET_DNIS
Events received by this script on "HandleEvents" function:
Commonly used events:
EVENT_CAS_BITS_CHANGED
EVENT_WINK_DETECTED
EVENT_WINK_COMPLETED
EVENT_ANI_RECEIVED
EVENT_DNIS_RECEIVED
EVENT_ANI_SENT
EVENT_DNIS_SENT
EVENT_APP_FWD_MAKE_CALL
EVENT_APP_BWD_MUST_ALERT
EVENT_APP_BWD_MUST_ANSWER
EVENT_APP_END_SIGNALING
EVENT_APP_BLOCK_TIMESLOT
EVENT_APP_UNBLOCK_TIMESLOT
EVENT_TIMEOUT
Additional events to implement special variants
EVENT_TONE_RECEIVED
EVENT_TONE_SENT
Result code that HandleNewTimeslot or HandleEvent funtions must return:
RESULT_OK
RESULT_FAIL
RESULT_MISMATCH
RESULT_OUT_OF_RESOURCE
RESULT_INVALID_PARAM
RESULT_INVALID_STATE
RESULT_NOT_SUPPORTED
RESULT_TRUNK_RES_NOT_IDLE
RESULT_BLOCKED_LOCALLY
RESULT_BLOCKED_REMOTELY
Call release causes to use with ACTION_END_SIGNALING
CAUSE_FWD_SEIZURE_COLLISION
CAUSE_FWD_SEIZURE_ACK_TIMEOUT
CAUSE_FWD_TONE_TIMEOUT
CAUSE_FWD_ANSWER_TIMEOUT
CAUSE_FWD_CALL_REFUSED
CAUSE_FWD_REJECT_CALL
CAUSE_FWD_HANG_UP
CAUSE_BWD_TONE_TIMEOUT
CAUSE_BWD_REJECT_CALL
CAUSE_BWD_CALL_REFUSED
CAUSE_BWD_ALERT_TIMEOUT
CAUSE_BWD_ANSWER_TIMEOUT
CAUSE_BWD_HANG_UP
Trace levels (used with function StackLogTrace).
Least verbose is TRACE_LEVEL_0 (almost never printed).
Most verbose is TRACE_LEVEL_4 (generally printed)
TRACE_LEVEL_0
TRACE_LEVEL_1
TRACE_LEVEL_2
TRACE_LEVEL_3
TRACE_LEVEL_4
TRACE_LEVEL_ALWAYS
TRACE_LEVEL_ERROR
-----------------------------------------------------------------------
4. Mandatory functions to implement in this script
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The script must provide the following mandatory functions, that will
be called by the CAS stack at appropriate moments.
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4.1 HandleNewTimeslot( in_TimeslotCtx, in_InitialCasBits )
This function is called to prepare a new timeslot so it's ready to
be used to receive events and eventually handle a CASR1 call.
When this function is called, the timeslot must be set to "off-hook"
state. The stack will later send EVENT_APP_UNBLOCK_TIMESLOT when
it's time to go "on-hook" and be ready to make calls.
Parameters:
in_TimeslotCtx :
Context containing variables for this timeslot.
This context is a LUA table.
This table already contains two values:
["TrunkNumber"] and ["TimeslotNumber"]
The script can create it's own variables here (like the
"call state"), which will be accessible for any event on
this timeslot.
in_InitialCasBits :
The initial states of CAS bits received from remote equipment
(integer like 0x1111)
-----------------------------------------------------------------------
4.2 HandleEvent( in_TimeslotCtx, in_EventType, ... )
This function reports that an event occurred on a timeslot
Parameters :
in_TimeslotCtx :
Timeslot context used by the script to store any timeslot-
related information, like the "call state".
This is the table that was passed to HandleNewTimeslot.
in_EventType :
The type of the event that was just received
(see constants EVENT_* documented below)
... :
Variable number of parameters, that depend on event type.
Available event types and their parameters:
EVENT_CAS_BITS_CHANGED:
Parameter:
- Received CAS bits (integer like 0x1111)
Indicates that CAS bits values received by
remote equipment have changed.
EVENT_WINK_DETECTED:
No specific parameter.
Indicates that a "Wink" has been detected.
This event can only follow ACTION_WAIT_WINK.
EVENT_WINK_COMPLETED:
No specific parameter.
Indicates that a "Wink" has been sent successfully.
This event can only follow ACTION_SEND_WINK.
EVENT_TONE_RECEIVED
Parameter:
- String that represents the received tone (digit)
(see "Digit format" below)
Indicates that a tone was detected.
Not normally used in CASR1 standard variants.
Note: This does not include tones that are
collected as part of ACTION_WAIT_ANI or
ACTION_WAIT_DNIS, which are coalesced and
reported as separate events.
EVENT_ANI_RECEIVED
No specific parameter.
Indicates that ANI (calling number) has been
sent received (prefix/suffix detected).
This event can only follow ACTION_WAIT_ANI.
Note: The received ANI/DNIS digits are not passed
to the script. The script does not have
to know them. But the stack keeps them
and they will be reported to the
application upon ACTION_REPORT_VALIDATE_CALL
EVENT_DNIS_RECEIVED
Same as EVENT_ANI_RECEIVED, but for DNIS
(called number)
EVENT_TONE_SENT
No specific parameter.
Indicates that a tone (digit) as been sent
successfully following ACTION_SEND_TONE.
Not normally used in CASR1 standard variants.
EVENT_ANI_SENT
No specific parameter.
Indicates that ANI (calling number) has been
sent successfully (all tones played).
This event can only follow ACTION_SEND_ANI.
EVENT_DNIS_SENT
Same as EVENT_ANI_SENT, but for DNIS
(called number)
EVENT_APP_FWD_MAKE_CALL
No specific parameter.
Indicate that a new "forward" call must be made.
The script shall take appropraite actions to
initiate a new call (most likely change the
CAS bits to the "off hook" state).
EVENT_APP_BWD_MUST_ALERT
No specific parameter.
Indicates that this "backward" call must now
be set to "alerted" state (meaning we have accepted
the call, and received required information to
proceed). The decision of when to alert the call
is made by the application, and at that moment
the script receives this event so it can take
appropriate actions to alert a "backward" call.
(in most variants, there is nothing to do, on
some variants, a "Wink" may be sent).
EVENT_APP_BWD_MUST_ANSWER
No specific parameter.
Indicates that this "backward" call must now
be set to "answered" state. The decision of when
set the call "answered" is made by the application,
and at that moment the script receives this event
so it can take appropriate actions to answer.
(in most variants, CAS bits must be set to
an "answered" pattern).
EVENT_APP_END_SIGNALING
No specific parameter.
Indicates either that:
- Application requests to terminate the call.
The script then take appropriate action, like
sedding CAS bits to "idle" state, wait for
remote equipment to acknowledge, then at the
end use ACTION_END_SIGNALING to confirm that
termination is completed.
- Script previously called ACTION_END_SIGNALING,
(after remote equipment set CAS bits to "idle"
or after an error in the script), in which
case this event confirms that the application
is also ready to terminate the call.
EVENT_APP_BLOCK_TIMESLOT
No specific parameter.
Indicates that the timeslot must be locally
blocked, the next time it becomes "idle".
It's blocked by going "off-hook" and remaining
in that state no matter remote state.
This is also the default state for a newly
created timeslot.
This state can only be canceled by
EVENT_APP_UNBLOCK_TIMESLOT
EVENT_APP_UNBLOCK_TIMESLOT
No specific parameter.
Cancels a previous EVENT_APP_BLOCK_TIMESLOT.
This causes our CAS bits to be set to "on hook".
EVENT_TIMEOUT
No specific parameter.
Indicates that the timer previously started with
ACTION_START_TIMER has expired.
Returns :
RESULT_OK, or one of the return codes defined above.
This result code tells to the stack if the event was properly
handled by the script. Upon non-OK code, the stack may decide
to terminate the call.
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5. Stack functions that can be called by this script
-----------------------------------------------------------------------
-----------------------------------------------------------------------
5.1 StackActionToString( in_Action )
Returns string value of an action type.
Example:
local action = ACTION_END_SIGNALING
StackActionToString( action )
will return the string "ACTION_END_SIGNALING".
-----------------------------------------------------------------------
5.2 StackEventToString( in_Event )
Returns string value of an event type.
Example:
StackEventToString( in_Event )
will return the string "EVENT_TIMEOUT".
-----------------------------------------------------------------------
5.3 StackCauseToString( in_Cause )
Returns string value of a release cause.
Example:
my_release_cause = CAUSE_FWD_SEIZURE_COLLISION
StackCauseToString( my_release_cause )
will return the string "CAUSE_FWD_SEIZURE_COLLISION".
-----------------------------------------------------------------------
5.4 StackLogTrace( in_TraceLevel, in_Format, ... )
Asks the stack to print a trace (generally debug traces).
Traces will be sent to the "tblogtrace" application.
Parameters:
in_TraceLevel:
Level of the trace (see TRACE_LEVEL_* above)
in_Format:
String that contains the trace to print, plus refernences
to other arguments ("printf" style format)
...:
Values for printf-style refernces of in_Format.
Example:
local cas_bits = 0x1100
StackLogTrace( TRACE_LEVEL_2, "Send CAS bits %08X", cas_bits )
will print "Send CAS bits 1100" to tblogtrace log.
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5.5 StackAction( in_Action, ... )
This function executes the specified action (in some cases with
the specified action-specific arguments).
The action is done asynchronously, meaning that control will
immediately return to the script. Events will be received later
according to the actions taken.
Upon an event, the script may perform multiple actions (like
starting a timer, declarign the call "alerted" and sending
CAS bits for example)
Parameters :
in_Action :
The action to perform.
(see constants ACTION_* documented below)
... :
Variable number of action-specific arguments.
ACTION_END_SIGNALING:
Parameter:
- The call release cause to report.
See values "CAUSE_".
Indicates either that:
- Application previously requested to terminate
the call (with EVENT_APP_END_SIGNALING), in
which case this action is used by the script
to indicate that signaling is fully idle (local
CAS bits set to "idle", remote equipment
has acknowledged too with "idle" CAS bits).
- Script wants to terminate the call
(after remote equipment set CAS bits to "idle"
or after an error in the script). After
sending ACTION_END_SIGNALING, the script must
wait until EVENT_APP_END_SIGNALING is
received, which confirms that application is
ready to terminate the cally. Only at that
moment the script shall set it's CAS bits
to "idle" value.
ACTION_SET_CAS_BITS
Parameter:
- CAS bits to set (integer like 0x1111)
Used to change the CAS bits that we are
sending on current timeslot towawrd remote
equipment.
ACTION_SEND_WINK
Parameters:
- CAS bits to set during the "Wink"
(integer like 0x1111)
- Duration of the "Wink" (in milliseconds)
Used to send a "Wink", which is temporary change of
the CAS bits for few milliseconds, then back to
initial CAS bits value.
EVENT_WINK_COMPLETED will be received by
the script once Wink has completed (CAS bits are
back to their initial value)
ACTION_WAIT_WINK
Parameters:
- Expected CAS bits during the "Wink"
(integer like 0x1111)
- Minimum duration of the "Wink" (in ms)
- Maximum duration of the "Wink" (in ms)
Used to request a "Wink" detection.
Upon next CAS bits change from remote equipment,
the stack will see if the bits match the Wink
expected bits.
EVENT_WINK_DETECTED will be reported
if CAS bits received from remote equipment change
to the expected pattern for a duration within
specified range, then go back to original value.
Any other CAS bits change not deteced as a "Wink"
will be reported to the script by
EVENT_CAS_BITS_CHANGED (which will probably want
to drop the call because a Wink was expected)
ACTION_SEND_TONE
Parameters:
- Digit (tone) to send.
(see "Digit format" below)
Used to send one digit (tone) toward remote
equipment. EVENT_TONE_SENT will be received
once the tone has been successfully sent.
Not normally used in CASR1 standard variants.
Note: This action is not used to send ANI/DNIS
(calling/called numbers), it's used to
send other tones that may be used within
the current CASR1 variant call flow.
ACTION_SEND_ANI
Parameters:
- Prefix to send before ANI. Can be empty.
- Suffix to send after ANI. Can be empty.
(see "Digit format" below)
Used to send ANI (calling number) toward
remote equipment, using tones.
A prefix may be inserted before ANI.
A suffix is mandatory. It's transmitted after ANI.
Remote equipment expects that suffix to determine
that the ANI has been entirely sent.
EVENT_ANI_SENT will be received once
transmission of prefix + ANI + suffix completed
ACTION_SEND_DNIS
Same as ACTION_SEND_ANI, but for sending DNIS
(called number)
ACTION_WAIT_ANI
Parameters:
- Prefix to expect before ANI. Can be empty.
- Suffix to expect after ANI. Can be empty only
if next argument (nb expected digits) is set.
(see "Digit format" below)
- Number of expected digits.
Optional. Only required if suffix is empty.
Used to wait for ANI (calling number) from
remote equipment, by detecting tones.
A prefix may be expected before ANI.
A suffix is mandatory. It's received after ANI to
indicate that the ANI has been entirely transmitted.
EVENT_ANI_RECEIVED will be received if a
matching prefix + suffix are detected.
ACTION_WAIT_DNIS
Same as ACTION_WAIT_ANI, but for receiving DNIS
(called number)
ACTION_SET_ANI
Parameters:
- ANI to set
Used to replace the ANI detected by the stack with
this ANI provided by the script.
This action must be calld before action
TBX_CASR2VMLIB_CASR1_ACTION_REPORT_VALIDATE_CALL
(otherwise it's too late to set ANI)
Not normally used in CASR1 standard variants.
ACTION_SET_DNIS
Same as ACTION_SET_ANI, but for DNIS (called number)
ACTION_REPORT_SEIZURE
No parameter.
Tell the application that seizure (off-hook) has
been deteced on a timeslot.
ACTION_REPORT_VALIDATE_CALL
No parameter.
Tell the application that ANI and/or DNIS have
been successfully received, and we now have the
information required to process this incoming call.
ACTION_REPORT_ACCEPTED
No parameter.
Tell the application that a "forward" call has
been accepted by remote equipment, often by
detecting a "Wink".
ACTION_REPORT_ALERTED
No parameter.
Tell the application that a "forward" call has
been alerted by remote equipment.
On most variants, there is no specific indication
from remote side, and this action must be taken
upon EVENT_DNIS_SENT.
On other variants, a "Wink" may be awaited before
calling this action.
ACTION_REPORT_ANSWERED
No parameter.
Tell the application that a "forward" call has
been answered by remote equipment, generally
because "off-hook" CAS bits have been received.
ACTION_REPORT_BLOCKED
No parameter.
Tells the application that the script considers
the timeslot as "remotely blocked". This is the
case when remote side goes "off hook" and remains
in that state for some duration after we've
returned to "on hook" on our side.
ACTION_REPORT_UNBLOCKED
NO parameter.
Tells the application that the timeslot is no
more "remotely blocked", because remote
equipment went "on hook" after we reported
ACTION_REPORT_BLOCKED.
ACTION_START_TIMER
Parameter:
- Timer duration in milliseconds.
Starts a timer. EVENT_TIMEOUT will be
posted if the timer expires before
ACTION_CANCEL_TIMER is called.
ACTION_CANCEL_TIMER
No parameter.
Cancels a timer previously started with
ACTION_START_TIMER.
Digit format:
The digit format (for sending tone or ANI/DNIS prefix/suffix)
is represented by a string that contains up to 3 of the
following characters: 0123456789ABCD*#
