Datasets:
Squidnutz
/
extractedtest

Dataset card Data Studio Files
xet
 Community
1
text
stringlengths
0
152
While you’ll find CURL() itself to be quite simple to use, the creation of the web appli‐
cation will require experience with web development.
func_odbc
Using func_odbc, it is possible to develop extremely complex applications in Asterisk
using nothing more than dialplan code and database lookups. If you are not a strong
programmer but are very adept with Asterisk dialplans and databases, you’ll love
func_odbc just as much as we do. Check it out in Chapter 15.
AGI
The Asterisk Gateway Interface is such an important part of integrating external
applications with Asterisk that we gave it its own chapter. You can find more infor‐
mation in Chapter 18.
AMI
The Asterisk Manager Interface is a socket interface that you can use to get configura‐
tion and status information, request actions to be performed, and be notified about
things happening to calls. We’ve written an entire chapter on AMI as well. You can
find more information in Chapter 17.
ARI
Asterisk’s REST interface builds on knowledge gained over the years about how to
integrate Asterisk with current-generation web-centric applications. It is so impor‐
tant, that yes, once again, there is a complete chapter dedicated to it. If you’re looking
to build complex IVRs using Asterisk, take a closer look at ARI in Chapter 19.
Asterisk Modules for Building IVRs
|
293
A Simple IVR Using CURL()
Before we go running off writing an external program to handle something, we
always give some careful thought about whether there’s a way to do the work in the
dialplan. One powerful way that Asterisk can interact with external data is through a
URL, which the GNU/Linux program cURL does very well. In Asterisk, CURL() is a
dialplan function.
We’re going to use CURL() as an example of what an extremely simple IVR can look
like. We’re going to request our external IP address from https://ipinfo.io/ip.2
In reality, most IVR applications are going to be far more complex.
Even most uses of CURL() will tend to be complex, since a URI can
return a massive and highly variable amount of data, the vast
majority of which will be incomprehensible to Asterisk. The point
being that an IVR is not just about the dialplan; it is also very much
about the external applications that are triggered by the dialplan,
which are doing the real work of the IVR.
The CURL() module was installed during our installation process several chapters ago.
The Dialplan
The dialplan for our example IVR is very simple. The CURL() function will retrieve
our IP address from https://ipinfo.io/ip, and then SayAlpha() will speak the results to
the caller:
exten => *764,1,Verbose(2, Run CURL to get IP address from whatismyip.org)
same => n,Answer()
same => n,Set(MyIPAddressIs=${CURL(https://ipinfo.io/ip)})
same => n,SayAlpha(${MyIPAddressIs})
same => n,Hangup()
The simplicity of this is impossibly cool. In a traditional IVR system, this sort of thing
could take days to program, assuming it would be possible at all.
A Prompt-Recording IVR Function
In Chapter 14, we created a simple bit of dialplan to record prompts. It was fairly
limited in that it only recorded one filename, and thus for each prompt a separate
2 These free IP lookup websites seem to get bought out all the time, and turned into advertising gateways, so
what might have worked at this writing may no longer work. What you need is a website that will return your
IP address, and nothing else. Today, that seems to be https://ipinfo.io/ip. By the time you read this, it may be
something else.
294
|
Chapter 16: Introduction to Interactive Voice Response
extension was needed. Here, we expand upon that to create a complete menu for
recording prompts. Since this is a complex bit of dialplan, but it’s not a subroutine or
a local channel, we’re going to create a new section of dialplan for various features,
and put things like this there:
;FEATURES
[prompts]
exten => s,1,Answer
exten => s,n,Set(step1count=0) ; Initialize counters
; If we get no response after 3 times, we stop asking
same => n(beginning),GotoIf($[${step1count} > 2]?end)
same => n,Read(which,prompt-instructions,3)
same => n,Set(step1count=$[${step1count} + 1])
; All prompts must be 3 digits in length
same => n,GotoIf($[${LEN(${which})} != 3]?beginning)