TCL vs. VXML Applications

TCL and VoiceXML are two different approaches to provide automated functions on voice gateway such as IVR, B-ACD, CAC, Calling Routing Maniplution, etc.

The main difference between Tcl and VoiceXML is that the router executes a Tcl scripts by it self (the script can be stored locally or remote location), whereas a VoiceXML script is a client-server model. If the gateway associates a call with a VoiceXML application, the application loads the appropriate VoiceXML document that can call for the gateway to interact with various web applications. This document might play audio prompts and collect digits. You can load additional VoiceXML documents based on the caller input.

Note: MGCP is not supported with Tcl or VoiceXML applications. To support applications, the gateway 

Deploying TCL Scripts and VoiceXML

For TCL scripts below are the required steps:

1.       Load the script to flash memory or the TFTP server

HQ#dir

Directory of flash:/

   47  -rw-       30421  Jan 24 2010 00:37:46 +00:00  app-b-acd-3.0.0.2.tcl

   48  -rw-     1016832  Jan 24 2010 00:37:36 +00:00  app-b-acd-3.0.0.2-ReadMe.txt

   49  -rw-       55599  Jan 24 2010 00:38:06 +00:00  app-b-acd-aa-3.0.0.2.tcl

2.       Load the associated audio prompts to flash memory or the RTSP server

HQ#dir

Directory of flash:/

    7  -rw-       75650  Jan 24 2010 00:38:30 +00:00  en_bacd_allagentsbusy.au

    8  -rw-       83291  Jan 24 2010 00:38:58 +00:00  en_bacd_disconnect.au

    9  -rw-       63055  Jan 24 2010 00:39:20 +00:00  en_bacd_enter_dest.au

   10  -rw-       37952  Jan 24 2010 00:39:34 +00:00  en_bacd_invalidoption.au

   11  -rw-      496521  Jan 24 2010 00:42:08 +00:00  en_bacd_music_on_hold.au

   12  -rw-      123446  Jan 24 2010 00:42:48 +00:00  en_bacd_options_menu.au

   13  -rw-       42978  Jan 24 2010 00:43:04 +00:00  en_bacd_welcome.au

3.       Initialize the application

application

   service application-name location

4.       Specify the initial local parameter values

application

   service application-name

   param parameter-name value

5.       Configure the dial peers to use the script or ephone-dn/voice register pool.

dial-peer voice ID [voip|pots]

   service application-name

or

ephone-dn ID

   application application-name

or

voice register pool ID

   application application-name

TCL/VoiceXML services are applied to inbound dial-peers (inbound calls only). To apply them to outbound calls,

dial-peer voice ID [voip|pots]

   service application-name outbound

6.       TCL scriptes can call packages. Packages are C subrouties or functions which can be called by the main script (program). Packages should be uploaded to flash or TFTP server and defined as below:

package package-name location

Then the package can be called using its name in the TCL script. To check all available packeges use the command show call application voice summary

7.       Specify the initial global parameter values

Parameters have two types: local and global. Local parameters are defined per script (you can have two local parameters sharing same name in two different scripts. Each will be initialized individually) while global parameters are shared between all scripts.

Global parameters initialization is applied in one location and will impact the same parameter in all scriptes sharing it. An example of global paramters are package parameters.

Below command can be used to initialize global parameters:

paramspace parameter-namespace parameter-name parameter-value

This can be applied per dial-peer,  service level (global), per-package with precendece order from high (dial-peer) to low (package) in case same initialization applied at differnet locations.

Note: If you change a parameter value, you must reload the script for the changes to take effect.

For VXML deployments:

1.       Initialize the application

application

   service application-name location

Note: The location of the VXML should point to VXML server, e.g. Mobile Voice Access

2.       Configure the dial peers to use the application or ephone-dn/voice register pool.

dial-peer voice ID [voip|pots]

   service application-name

or

ephone-dn ID

   application application-name

or

voice register pool ID

   application application-name

TCL/VoiceXML services are applied to inbound dial-peers (inbound calls only). To apply them to outbound calls,

dial-peer voice ID [voip|pots]

   service application-name outbound

3.       Configure an outbound dial peer (SIP/H323) pointing to VXML server.

Note: Inbound dial-peers providing TCL/VXML applications can’t be used for other purposes, e.g. normal inbound PSTN calls.