stuff we noticed while buildingAsterisk in the cloud

Atlanta Asterisk Users Group

Troy Davistroy@yort.com

twitter.com/troyd

cloudvox.com@cloudvox@ifbyphone

Every cloud is special in its own way

Automated Phone Calls

• Riding on 10 years • Have framework(s), need appS• What can we build, quickly?

AGI

• Java (Asterisk-Java)• Ruby (Adhearsion, Telegraph, RAGI)• Perl (Asterisk::FastAGI)• PHP (PHP-AGI)• Python (Twisted/StarPy)• C# (monotone, Asterisk.NET)• C (CAGI)

Adhearsion

• Serverahn start daemon voiceapp/

Adhearsion

• Serverahn start daemon voiceapp/ • Entry points

server hits:   agi://any.where.org/acontext?b=cclient runs:  acontext { Ruby-as-dialplan }

Dialplan Representations

Bindings match Asterisk• Exposes native Asterisk calls• Different languages (mostly) look the same• PHP-AGI, Asterisk::AGI, basic Asterisk-Java, RAGI

Dialplan Representations

Bindings match Asterisk• Exposes native Asterisk calls• Different languages (mostly) look the same• PHP-AGI, Asterisk::AGI, basic Asterisk-Java, RAGI

Bindings match language model• Wrap head around abstraction• Easier to maintain, harder to replace• Adhearsion, full Asterisk-Java, Telegraph

Dialplan Representations

Bindings match Asterisk• Exposes native Asterisk calls• Different languages (mostly) look the same• PHP-AGI, Asterisk::AGI, basic Asterisk-Java, RAGI

Bindings match language model• Wrap head around abstraction• Easier to maintain, harder to replace• Adhearsion, full Asterisk-Java, Telegraph

Think like Asterisk or think like the language?

PHP-AGI

• Serverxinetd • Entry points

server hits:   agi://any.where.org/?b=cxinetd executes:  myapp.php # very dialplan-ish PHP

gist.github.com/4670 - Adhearsion

gist.github.com/4670 - get phone #

Phone + HTTP service (Telegraph)

• Don't transfer burden to user• Where does phone-specific code sit?• Latency

IVR forms (Telegraph)

tinyurl.com/marsphoenix - Poll

 

tinyurl.com/marsphoenix - Call

• App-initiated• Channels• Sync/async

Testing

• “Can you here me now?” is barely testing

Process

• “Can you here me now?” is barely testing

• Paper first• Small first• Placeholders first

• Debugging tools

Deployment

AGI(agi://else.where.com/agi.pl|arg1|arg2|...)

or

AGI(agi.pl|arg1|arg2|...)

Harder than it could be

• ASR & good TTS• SMS• Video

DTMF Anywhere

Event: DTMF

Privilege: dtmf,allChannel: IAX2/instance-X-YYYUniqueid: cloudvox.com-12345Digit: 5Direction: ReceivedBegin: NoEnd: Yes

Conference Pipes

• fake conference call participant

• creative use of Originate 

• Channel + Context 

= magic Music on Hold, Playback, Speak, <anything> intoa conference room

Bring your own carrier, or don't

• carriers are specialized

• Cloudvox isn't everywhere

• we're a hosting service

sip:<any number or exten>@<x>.cloudvox.com

Bring your own carrier, or don't

• carriers are specialized

• Cloudvox isn't everywhere

• we're a hosting service

sip:<any number or exten>@<x>.cloudvox.com

• priced for use: remote SIP == 1 cent per minute

Number metadata API (free)http://digits.cloudvox.com/4252101234.json

Number metadata API (free)http://digits.cloudvox.com/2124561111.json (White House)

Number metadata API (free)http://digits.cloudvox.com/6506929100.json

<phone number you care about>

<phone number you care about>

http://digits.cloudvox.com/

<phone number you care about> <.json>

http://digits.cloudvox.com/

DNS API

host -t TXT 2065460420.na.digits.cloudvox.com

What can I do?

• Get realtime number info from existing tools

• Augment phone number displays

• Analyze a group of numbers

• Customize call logic

Be lazy in what you send,and liberal in what we accept.

• 10, 7, 6, 3 digits

• Already parsed, or best guess

• Same reply format for all queries

• REST, DNS, browser

AGI + SMS to same numbers

• "Call or SMS 206-555-1234"

• No short code or shared code

• Not integrated with Asterisk (HTTP is simpler)

• Maybe down the road?

Asterisk scaling: call-as-unit

Asterisk scaling: data store routing

Asterisk scaling: standard components

Asterisk scaling: escape valve(s)

Questions?

Troy Davis

troy@yort.comtwitter.com/troyd

cloudvox.com

@cloudvox@ifbyphone