TCL Example: B-ACD Based TCL

I thought to elaborate more on TCL side since VXML complexity is centerlized at server level (from gateway side nothing is required that pointing to VXML server). For this purpose I thought about explaining B-ACD based TCL in details.

B-ACD application is used to provide call queuing with IVR capabilities. Each B-ACD application is made of two TCL scripts: Auto-Attendant script and Call Queue script. Call queuing is provided by the combining call queue script and ephone-hunt groups (Voice Hunt Groups can’t be used with B-ACD. You can still forward from ephone-hunt to voice hunt-group but voice hunt-group pilot can’t be assigned to call queue script).

Before going into application details, below is the flow chart to understand how it works:

Following the TCL implmentation steps mentioned in the previous blog:

1. Upload the scripts (both AA & Call queue) into gateway flash (Completed)
2. Upload the associated audio files into gateway flash (Completed)

3. Initialize local and global parameters. 

This is the major part of B-ACD application. As mentioned  B-ACD application is made of two scripts (AA & Call Queue). Therefore, the parameters for both scripts should be initialized.

a.       AA-IVR pilot DN under aa-script (param aa-pilot number). Secondary number can be configured (param aa-pilot2 number).

b.      Welcome prompt and other audio files under aa-script. Customized prompts can be uploaded using the same default prompt name (overrite) or using different names.

c.       Language and language codes under aa-script (global parameter). Default language used is English and code is en. Other supported lanaguages are Chinese (ch) and Spanish (sp). Also, all three lanaguages can be enabled simultenously (aa)

d.      Map menu options under aa-script. AA-script contain the following menu options:

a.       3 hunt groups (range from 1-3)

b.      1 operator (0)

c.       1 dial-by-extension (param dial-by-extension-option menu-number)

Therefore the max number of hunt-groups to be configured in aa-script is 3 since operator and dial-by-extension are not counted in aa-script as hunt-groups (param numer-of-hunt-grps number).

The hunt-groups and operator in aa-script are mapped to ephone-hunt pilots through queue script as follow:

param aa-huntmenu-number ephone-hunt-pilot

*** The highest configured menu number will be used for operator when 0 is pressed. It can point to ephone directly instead of hunt pilot. ONLY EPHONES NOT DIAL-PEERS***

param number-of-hunt-grps number

***This varies from (1-10). BUT, Why the max number of hunt-groups can be 10 if only 3 hunt groups can be supported in aa-script ????

The main reason is that one queue script can be shared between multiple aa-scripts. Assume aa-script-1 has 3 hunt-groups and 1 operator, aa-script-2/3/4/5 have drop-through-option to different ephone-hunt groups, and all of those aa-scripts are using same queue script.

In this case the number of hunt-groups under queue script should be 3 (aa-script1) + 1 (aa-script-1 operator) + 4 (aa-script-2/3/4/5) = 8***

Important Note: dial-by-extension menu-number shouldn’t match any of hunt-group menu numbers in queue script. Example: If dial-by-extension menu-number is 1, then options 2, 3, 4 will be available in aa-script. Accrodingly aa—huntmenu-number in queue-script should have numbers 2, 3, 4 (and shouldn’t have number 1).

e.      AA-script can be used in drop-through mode. In this case AA will send the call directly to call-queue script without playing any prompt to caller (as if the caller is dialing the hunt group directly).  If an agent is avialalbe the caller will hear a ringback however, if all agents are busy the caller will hear MOH. To set drop-through-option parameter:

param drop-though-option ephone-hunt-group-number

param drop-though-prompt audio-file-name     !!... In case prompt is required

f.        Call queue exit option in aa-script. Upto 3 hunt groups can be configured for call queue exit option using the command param queue-exit-optionephone_hunt_group_number menu_number. The prompt used for call queue exit is the second greeting stored under the name en_bacd_allagentbusy.au. Optionally the call queue can point to extension directly using the command param queue-exit-extensionoption_number extension_number

g.       Voice Mail pilot number in aa-script. In case the call isn’t answered it can be forwarded to voice mail pilot using param voice-mail number. This number can be a voice mail pilot, SCCP/SIP extension, or any other destination matching dial-peer.

Adding to above parameters, following are some restrictions to be considered when deploying B-ACD:

1.       MoH source should be configured either in telephony service ro call-manager-fallback. Else, the application will throw error and drop the call.

2.       The codec used for voip calls should be G711 only. Even, if XCODE is available, B-ACD won’t trigger it.

Here is a full configuration example including all TCL implementation steps in the previous blog:

voice register dn  1

 number 3005

 name br2 phn 3

!        

voice register dn  2

 number 3006

 name br2 phn 4

!

voice hunt-group 1 parallel

!!!... Forward to voice-mail (5015) if no answer

 final 5015

 list 3001,3005,3006

 timeout 89

 pilot 3210

 !

application

 service aa flash:app-b-acd-aa-3.0.0.2.tcl

!!!... Define the language used by the script

  paramspace english index 1

!!!... Define language prefix

  paramspace english language en

!!!... Define audio files location for this language

  paramspace english location flash:

  param number-of-hunt-grps 2

!!!... Define welcome prompt audio file. Note that en prefix is removed from file name (_bacd_welcome.au). The reason is that we defined language as English (en), thus prefix will be added to prompt name making the full audio file name as en_bacd_welcome.au which is matching the file name in flash (location of English audio files).

  param welcome-prompt _bacd_welcome.au

  param aa-pilot2 3500

  param handoff-string aa

!!!... Define the maximum timer to set call in queue before sending it to voice mail

  param max-time-call-retry 90

  param voice-mail 5015

!!!... Assocaite call queue script with aa script

  param service-name queue

  param aa-pilot 32143500

 !

 service aa-drop flash:app-b-acd-aa-3.0.0.2.tcl

  param voice-mail 5015

  param max-time-call-retry 90

  param handoff-string aa-drop

  paramspace english index 1

  paramspace english language en

  param aa-pilot 32143501

  param service-name queue

  paramspace english location flash:

  param number-of-hunt-grps 1

  param drop-through-option 2

  param aa-pilot2 3501

 !

 service queue flash:app-b-acd-3.0.0.2.tcl

  param aa-hunt3 3001

!!!... Call queue length

  param queue-len 10

  param aa-hunt2 3211

!!!... To enable call queue traces

  param queue-manager-debugs 1

  param number-of-hunt-grps 2

 !

 dial-peer voice 12 pots

 description *** PSTN ---> AA ***

 service aa

 incoming called-number 32143500

 direct-inward-dial

 port 0/2/0:23

!

!!!... This dial-peer is a dummy one used for allow ephones to call B-ACD application. As mentioned earlier, we can’t assigned application to ephones directly. The workaround is to create and outbound dial-peer for B-ACD application pilot having session-target as gateway loopback interface, i.e. gateway calling it self.

dial-peer voice 13 voip

 description *** BR2 ---> AA ***

 service aa

 destination-pattern 3500

 voice-class codec 1

 session target ipv4:142.5.65.254

 incoming called-number 3500

!

dial-peer voice 14 pots

 description *** PSTN ---> AA-DROP ***

 service aa-drop

 incoming called-number 32143501

 direct-inward-dial

 port 0/2/0:23

!

dial-peer voice 15 voip

 description *** BR2 ---> AA-DROP ***

 service aa-drop

 destination-pattern 3501

 voice-class codec 1

 session target ipv4:142.5.65.254

 incoming called-number 3501

 !

 telephony-service

 moh en_bacd_music_on_hold.au

!

ephone-dn  1  octo-line

 number 3001 no-reg primary

 description 32143001

 name br2 phn1

!

ephone-hunt 1 sequential

 pilot 3211

 list 3001

 final 3210

!!!... To enable call queue statistics reporting

 statistics-collect

 max-timeout 90

 timeout 1

Verification and troubleshooting commands:

-          debug voice application

-          debug  voice application error

-          show call application ?

-          show ephone-hunt