RoR puede también hablar:
Interface de voz con Rails
Svet Ivantchev, eFaber
svet@efaber.net
22 de noviembre de 2007, ConferenciaRails 2007, Madrid

¿Qué es VoIP?

Ejemplos
... y 1000s más

¿Es por dinero?
• Ok, las llamadas VoIP son baratas pero no
eso es importante
• Flexibilidad y integración con aplicaciones

Demo
• Consulta de notas por web
• Consulta de notas por teléfono
La voz es una interface más

¿Por qué ahora?
• Web stack (ej: SO, BD, RoR :-))
• VoIP (ej: Asterisk)
• Ancho de banda
• Los IVR dejan mucho que desear

Asterisk (conceptos)
http://asterisk.org
• Centralita Open
Source (PBX)
• Protocolos: SIP, IAX
• Proveedores

Componentes
Clientes VoIP DID
SIP, IAX SIP, IAX
SIP, IAX
ZAP
Red PSTN Terminación

Asterisk (instalación)
compilamos:
$ wget http://downloads.digium.com/pub/
asterisk/releases/asterisk-1.4.13.tar.gz
$ tar zxvf asterisk-1.4.13.tar.gz
$ cd asterisk-1.4.13
$ ./configure
$ make menuselect
$ make
$ sudo make install
$ sudo make samples
comprobamos:
$ sudo asterisk -vvvvvc
voces en castellano: http://www.voipnovatos.es

Asterisk (config)
en /etc/asterisk/sip.conf
[pb15] [spa941]
context=demo1 context=demo1
type=friend type=friend
secret=sekreto42 secret=otrapassw
host=dynamic host=dynamic
canreinvite=no canreinvite=no
en /etc/asterisk/extensions.conf
[demo1]
exten => 101,1,Dial(SIP/pb15)
exten => 102,1,Dial(SIP/spa941)

Cliente softphone

Cliente hardware

Números públicos

DID y SIP URI

Demo
• Llamada entre dos números
• Con el número público

Ideas
• Respuesta diferente por horas
• Respuesta diferente en función del CallerID
• Integración con Jabber
• Voicemail
• IVR, colas
• 1000s de cosas mas ...

El dialplan se complica
[efmenu]
include => users5xx
include => rooms
include => efhq
exten => s,1,NoOp(Entering eF main menu for caller ${CALLERID})
exten => s,2,Answer
exten => s,3,Wait(2)
exten => s,4,Playback(beep)
exten => s,5,Background(${SALUDOEN}enter-ext-of-person)
exten => s,6,Background(beep)
exten => s,7,WaitExten(15)
exten => 101,1,Playback(room-service)
exten => 101,2,Goto(efmenu,s,4)
exten => 999,1,Goto(svetdisa,s,1)
exten => 999,2,Goto(efmenu,s,4)
exten => i,1,Playback(pbx-invalid)
exten => i,2,Goto(efmenu,s,6)
exten => t,1,Playback(vm-goodbye)
exten => t,2,Hangup()

...y se hace feo
exten => 508,1,Macro(voicemail,SIP/esti)
exten => 509,1,Macro(voicemail,SIP/kolio)
exten => 510,1,Macro(voicemail,SIP/jean)
exten => 511,1,Macro(voicemail,SIP/ruben)
exten => 512,1,Macro(voicemail,SIP/inaki)
[macro-voicemail]
exten => s,1,Dial(${ARG1},30)
exten => s,2,Goto(s-${DIALSTATUS},1)
exten => s-NOANSWER,1,Voicemail(u${MACRO_EXTEN})
exten => s-NOANSWER,n,Hangup()
exten => s-CHANUNAVAIL,1,Playback(unavailable)
exten => s-CHANUNAVAIL,n,Hangup()
exten => s-CONGESTION,1,Busy(5)
exten => s-CONGESTION,n,Hangup()
exten => s-BUSY,1,Voicemail(b${MACRO_EXTEN})
exten => s-BUSY,n,Hangup()
exten => _s-.,1,Goto(s-NOANSWER,1)

AGI y AMI
• Asterisk Gateway Interface
• Asterisk Manager Interface

Alternativas
• Adhearsion
• Telegraph

Adhearsion
http://adhearsion.com
• El dialplan escrito en Ruby
• ActiveRecord integrado
• Integración con Rails
• versiones (0.7.7 vs 0.8)

Adhearsion 1: Hello World
$ sudo gem install adhearsion
$ ahn create hello1
Creating /Users/svet/hello1/config/adhearsion.sqlite3
Creating /Users/svet/hello1/config/adhearsion.yml
Creating /Users/svet/hello1/config/database.rb
Creating /Users/svet/hello1/config/database.yml
Creating /Users/svet/hello1/config/helpers/drb_server.yml
Creating /Users/svet/hello1/config/helpers/factorial.alien.c.yml
Creating /Users/svet/hello1/config/helpers/growler.yml
Creating /Users/svet/hello1/config/helpers/lookup.yml
Creating /Users/svet/hello1/config/helpers/manager_proxy.yml
Creating /Users/svet/hello1/config/helpers/micromenus/collab.rb
...

Hello World
en /etc/asterisk/extensions.conf
[adhearsion]
exten => 101,1,AGI(agi://127.0.0.1)
$ cd hello1
en extensions.rb
dhearsion {
play 'hello-word'
}
$ ahn start .

internal {
case extension
when 101...200
employee = User.find_by_extension extension
if employee.busy? then voicemail extension
else
dial employee, :for => 10.rings
voicemail unless last_call_successful?
end
when 888
play weather_report(\"Dallas Texas\")
when 999 then +joker_voicemail
end
}

Adhearsion II: Amazon

require 'amazon/search'
r = Amazon::Search::Request.new( '10N1KX1NVQZ2VXXXXXXX')
begin
resp = r.keyword_search( '0596529260', 'books' )
resp.products.each do |p|
unless p.availability =~ /not available/
printf( \"%s (ASIN %s) -- %s\\n\",
p.product_name, p.asin, p.our_price )
end
end
rescue
puts \"No se encuentra.\"
end
$ ruby price2
RESTful Web Services (ASIN 0596529260) -- $26.39

Adhearsion II: Amazon
adhearsion {
require 'amazon/search'
r = Amazon::Search::Request.new( '10N1KX1NVQZ2VXXXXXXX')
begin
resp = r.keyword_search( extension, 'books' )
resp.products.each do |p|
unless p.availability =~ /not available/
play p.our_price
end
end
rescue
play \"no-info-about-number\"
end
}

voxbone {
sleep 2.seconds
play \"hello-world\"
isbn = input()
require 'amazon/search'
r = Amazon::Search::Request.new( '10N1KX1NVQZ2VXXXXXXX')
begin
resp = r.keyword_search( isbn, 'books' )
resp.products.each do |p|
unless p.availability =~ /not available/
play p.our_price
end
end
rescue
play \"no-info-about-number\"
end
}

Telegraph
http://telegraph.rubyforge.org
• MVC
• respond_to

Telegraph y AGI
exten => 105, 1, AGI(agi://127.0.0.1/my_route?param1=value)
wants.voice do
render_voice do |voice|
voice.play “hello-world”
voice.link_to_dtmf 'bank-lineitem-menu' do
link 1, :action=>\"new\"
link 2, :action=>\"list\"
link 3, :action=>\"index\"
end
end
end

Demo

<h1>Consultas</h1>
<ul>
<li> <%= link_to \"Faltas\", :action=>\"faltas\" %> </li>
<li> <%= link_to \"Notas\", :action=>\"notas\" %> </li>
</ul>
<h1>Consultar notas</h1>
<% form_tag '/alumnos/show_notas' do %>
DNI: <%= text_field_tag 'dni' %>
<%= submit_tag 'Ver notas' %>
<% end %>
def show_notas
@alumno = Alumno.find_by_dni(params[:dni])
@notas = @alumno.notas_ultima_evaluacion
end
<% @notas.each do |nota| %>
<tr>
<td class=\"list\"><%= nota.asignatura %></td>
<td class=\"list\"><%= nota.nota %></td>
</tr>
<% end %>

Telegraph
$ script/plugin install svn://rubyforge.org/var/svn/telegraph/trunk
en /etc/asterisk/extensions.conf:
exten => 777,1, AGI(agi://192.168.1.1:4574/alumnos/index)
en app/controllers/alumnos_controller.rb:
def index
respond_to do |wants|
wants.html { render }
wants.voice {
render_voice { |voice| voice.play_sound \"hello-world\" }
}
end
end

Telegraph: configuración
$ vi config/telegraph.yaml
development:
agi_server: 127.0.0.1
agi_port: 4574
ami_server: druby://localhost:9000
outgoing_call_path: /var/spool/asterisk/outgoing
wakeup_call_path: /var/spool/asterisk/wakeups
sound_path: /var/lib/asterisk/sounds
recording_path: /var/lib/asterisk/sounds
$ script/agi_server

respond_to
def index
respond_to do |wants|
wants.html { render }
wants.voice { render_voice }
end
end
$ vi app/views/alumnos/index.voice
voice.play_sound \"hello-world\"

index
# index.rhtml
<h1>Consultas</h1>
<ul>
<li> <%= link_to \"Faltas\", :action=>\"faltas\" %> </li>
<li> <%= link_to \"Notas\", :action=>\"notas\" %> </li>
</ul>
# index.voice
voice.play_sound 'thank-you-for-calling'
voice.link_to_dtmf 'presione1-2' do
link 1, :controller => \"alumnos\", :action => \"faltas\"
link 2, :action => \"notas\"
end

formulario
# notas.rhtml
<h1>Consultar notas</h1>
<% form_tag '/alumnos/show_notas' do %>
DNI: <%= text_field_tag 'dni' %>
<%= submit_tag 'Ver notas' %>
<% end %>
# notas.voice
voice.form :url=>{:controller =>
'alumnos', :action=>'show_notas'} do |form|
form.numeric_input 'dni', 'dni', :max_digits=>8
end

resultados
# show_notas rhtml
<h3>Notas de <%= @alumno.nombre %></h3>
<table class=\"list\">
<% @notas.each do |nota| %>
<tr>
<td class=\"list\"><%= nota.asignatura %></td>
<td class=\"list\"><%= nota.nota %></td>
</tr>
<% end %>
</table>
# show.voice
@notas.each do |nota|
voice.play nota.asignatura.to_slug
voice.play nota.nota
end
sleep 2.seconds
voice.play \"vm-goodbye\"

No hay que pasarse
• Web vs Mobile web vs Voz
• ej: 466453.com

Telegraph con AMI
$ script/generate ami_model AMIModel
# environment.rb (user y password en manager.conf):
Telegraph::AMIManager.establish_connection!(
:host=> 'your.host.name.com',
:username=>'user',
:secret=>'password')
$ script/ami_server
# usar así:
AMIModel.create(:call, :channel=>'SIP/101', :context=>'default',
:exten => 'outgoing', :priority=>1)

Links
• http://asterisk.org/
• http://www.voipnovatos.es
• http://www.voip-info.org
• http://adhearsion.com
• http://www.linuxjournal.com/article/9519
• http://telegraph.rubyforge.org
• http://telegraph.rubyforge.org/wiki/wiki.pl?UsingAGI

Q &A