This guide will instruct you on how to configure an instance of the onebusaway-phone-webapp interactive-voice-response (IVR) phone interface, as described in the phone service feature guide.
There is no standard for writing IVR applications, so the configuration will largely depend on which IVR provider you go with. OneBusAway supports the following providers by default:
Asterisk is a telephony application server that has a ton of features, including the ability to answer an incoming phone call and redirect it to an IVR application. Asterisk supports the FastAGI protocol for interacting with applications, which is the protocol well use to communicate with the OneBusAway phone application. Asterisk configuration is beyond the scope of this document (and pretty complex even with the right documentation), so well assume you already have some experience configuring and running Asterisk. To configure the OneBusAway phone IVR application, add an AGI entry for the application in your dialplan:
exten => 200,1,NoOp(OneBusAway IVR Application) exten => 200,2,Agi(agi://localhost:8001/index.agi,60,r) exten => 200,3,Hangup
Here, localhost is the hostname where you are running your server and 8001 is the default AGI port used by the phone application. You can change the default port by adding the following snippet to your data-sources.xml config file:
<bean class="org.onebusaway.container.spring.PropertyOverrideConfigurer"> <property name="properties"> <props> <prop key="agiServer.port">PORT</prop> </props> </property> </bean>
The default Asterisk text-to-speech is not great. I had better luck using a text-to-speech engine from Cepstral to generate the speech for the text in my IVR system. Cepstral has products that can probably directly integrate into Asterisk, but they are a bit pricey when you budget is as close to free as possible. Instead, I opted for a license that only allows you to run one text-to-speech session at a time on the command-line and just cache all the results, since most of the text in the IVR system ends up being largely static over time. To configure, I installed swift, the Cepstral text-to-speech application and configured my license. I also installed sox, which will be used to convert the files produced by swift into a form more usable by Asterisk.
Next, I override the default text-to-speech factory by adding the following to my data-sources.xml file:
<bean id="textToSpeechFactory" class="org.onebusaway.phone.impl.SwiftAndSoxTextToSpeechFactoryImpl"/>
This will instruct the OneBusAway phone application to generate a sound file for a snippet of text, save it to the Asterisk cache directory, and instruct Asterisk to play the sound file.
Often, the GTFS schedule data that powers your OneBusAway instance will often use words and abbreviations that are fine when displayed as text but give text-to-speech engines trouble. As such, we provide a mechanism for tweaking output text in the IVR system to aid in pronunciation. If you text-to-speech engine supports custom syntax for pronouncing tricky words, it can be used here as well.
First, create an xml file with the following syntax that defines translations for text in a more pronouncable form.
<?xml version="1.0" encoding="UTF-8"?> <text-modifications> <replacement from="ave" to="avenue" /> <replacement from="bthl" to="bothell" /> <replacement from="cc" to="community college" /> <replacement from="hwy" to="highway" /> <replacement from="lkview" to="lakeview" /> <replacement from="wash" to="washington" /> <text-modifications>
Then add the following configuration to your data-sources.xml file:
<bean id="pronunciationFactory" class="org.onebusaway.presentation.impl.text.XmlTextModificationsFactory"> <property name="resource" value="file:path/to/your/pronunciations.xml" /> </bean> <bean id="pronuncation" factory-bean="pronunciationFactory" factory-method="create"> <qualifier value="destinationPronunciation" /> </bean>
All told, you can tweak pronunciation in four different ways by creating beans that implement the TextModification interface and tagging them with a <qualifier value="KEY" /> tag. The four supported qualifiers are:
You can specify multiple qualifiers for a single bean if it can be used to support multiple pronunciations.