Copyright 2009 Twilio

twilio is a Cloud Service
for Web Developers to build and scale
Voice Communication Apps
that Make or Receive Phone Calls,
using only Basic Web Development skills

Pay Per Call Tracking
Private Calling
Outbound Alerts
Improve Customer Service
Coordinate Employees
Voicemail Boxes
So What Are
Voice Applications?
Reverse 911 Alerts
Intelligent Call Routing
Voice User Generated Content
Company PBX
Information Hot Line

uLaw Transcoding
Carriers Integration
PSTN
Channel Capacity
DID Acquisition
SIP Compatibility
Building Voice Applications Used to be
Codecs HARD QOS
Realtime CPU Capacity Planning
DTMF
Realtime Networking
Multiyear Carrier Contracts

Telecom Goo HTTP
XML
PSTN MP3, wav, etc.
CLECs
Twilio
SIP
uLaw
GSM
G.711
HARD EASY!

Customers & Brands

Platform
Launched Late 2008
Thousands of Devs
Hundreds of Live Apps

Simple, Powerful API
Only Five Building Blocks.
Scales Automatically
10 or 10,000 Simultaneous Calls.
Pay-As-You-Go Pricing
No upfront, no commitment. Pay only for what you use.

Powerful
^
Simple API
yP BX
pan
C om
ail
oi cem
V
ou ting
Ca ll R

Pa y-As-You-Go
^
Simple Pricing
Calls Phone Numbers
3¢ / min $5 / mo
No Contract
No Shenanigans

Pricing Voice Applications
# “Ports”
(Phone Lines)

Pricing Voice Applications
Peak
Median

Pricing Voice Applications
FAIL
Waste

Ports are for Ships
No Per Port Prices
Let Your Voice Applications Scale

Telephony in the Cloud
Cloud Provider & Consumer
Carr
Tele ier
Hard com
ware
Reliable Telecom without Fixed Costs
Pass Flexibility on to Customers
Powered By

Cluster Layout
AMAZON “Other” Cloud
Telephony + API
EC2 Realtime, high-CPU
SVN Code Deployment
Reliable Voice Monitoring +
S3 Recording Storage
NAGIOS
Alerting
Decouples SOA BOXCONFIG Capacity
SQS Components COORDINATOR Management
Privileged and Confidential
Failover Scenario

Twilio + EC2
HTTP VoIP
Load Balancer Load Balancer
Web Web API API VoIP VoIP
Load Balancer Load Balancer Load Balancer Load Balancer Load Balancer Load Balancer
Database Database Database
EC2
Privileged and Confidential

Twilio + EC2
Realtime Transcoding
<Play>http://myserver.com/foo.mp3</Play>
256kbps stereo MP3 ! 11khz 8bit mono ulaw
Example
<Record/>
http://api.twilio.com/..../Recordings/RE12345
http://api.twilio.com/..../Recordings/RE12345.mp3
11khz 8bit mono wav ! MP3
EC2
Privileged and Confidential

Twilio + EC2
HTTP VoIP
Load Balancer Load Balancer
Web Web API API VoIP VoIP
Load Balancer Load Balancer Load Balancer Load Balancer Load Balancer Load Balancer
Database Database Database Media Layer Media Layer
EC2
Privileged and Confidential

Twilio AMI
Cent5
3rd Party Software for All Machines
(Apache, MySql, HaProxy, etc.)
Automated Build Process
(out of SVN)
Rev’d Infrequently
(Every couple months or so)
AMI
EC2
Privileged and Confidential

AWS Realms
DEV STAGE PROD
AWS Account X AWS Account Y AWS Account Z
S3 SQS S3 SQS S3 SQS
Privileged and Confidential

Twilio + EC2
At Boot Time, Pulls Twilio Code from SVN
(What Code to Pull?)
SVN
AMI
EC2
Privileged and Confidential

SVN
SVN Externals
DEV
svnroot/some-codebase ! ./usr/local/some-codebase @HEAD
svnroot/come-config-files ! ./etc/some-config-files @HEAD
STAGE
svnroot/some-codebase ! ./usr/local/some-codebase @1000
svnroot/come-config-files ! ./etc/some-config-files @1005
PROD
svnroot/some-codebase ! ./usr/local/some-codebase @999
svnroot/come-config-files ! ./etc/some-config-files @1002
DEV STAGE PROD
FILESYSTEM FILESYSTEM FILESYSTEM
Privileged and Confidential

Twilio Boxconfig
Launches and Destroys Instances
Coordinates Load Balancers
UI + Pubsub + REST
BOXCONFIG
SVN
AMI
EC2
Privileged and Confidential

Pulling It All Together
Machine Startup/Shutdown
UI Boxconfig 1. Launch Instances
PUBSUB
REST API System 2. Configure Services per Role
3. Notify Interested Load Balancers
HTTP VoIP
Load Balancer Load Balancer
Web Web API API VoIP VoIP
Load Balancer Load Balancer Load Balancer Load Balancer Load Balancer Load Balancer
Database Database Database Media Layer Media Layer
Privileged and Confidential

Pulling It All Together
Machine Startup/Shutdown
UI Boxconfig 1. Launch Instances
PUBSUB
REST API System 2. Configure Services per Role
3. Notify Interested Load Balancers
1
HTTP VoIP
Load Balancer Load Balancer
Web Web API API VoIP VoIP
Load Balancer Load Balancer Load Balancer Load Balancer Load Balancer Load Balancer
Database Database Database Media Layer Media Layer Media Layer
Privileged and Confidential

Pulling It All Together
Machine Startup/Shutdown
UI Boxconfig 1. Launch Instances
PUBSUB
REST API System 2. Configure Services per Role
3. Notify Interested Load Balancers
1
HTTP VoIP
Load Balancer Load Balancer
Web Web API API VoIP VoIP
Load Balancer Load Balancer Load Balancer Load Balancer Load Balancer Load Balancer
Database Database Database Media Layer Media Layer Media Layer
Privileged and Confidential
2 SVN

Pulling It All Together
Machine Startup/Shutdown
UI Boxconfig 1. Launch Instances
PUBSUB
REST API System 2. Configure Services per Role
3. Notify Interested Load Balancers
1
HTTP VoIP
Load Balancer Load Balancer
Web Web API API VoIP VoIP
Load Balancer Load Balancer Load Balancer Load Balancer Load Balancer Load Balancer
Database Database Database Media Layer Media Layer Media Layer
Privileged and Confidential
2 SVN

Pulling It All Together
Machine Startup/Shutdown
UI Boxconfig 1. Launch Instances
PUBSUB
REST API System 2. Configure Services per Role
3. Notify Interested Load Balancers
1
HTTP VoIP
Load Balancer Load Balancer
Web Web API API VoIP VoIP
Load Balancer Load Balancer Load Balancer Load Balancer Load Balancer Load Balancer
Database Database Database Media Layer Media Layer Media Layer
3
Privileged and Confidential
2

Pulling It All Together
Machine Startup/Shutdown
Boxconfig 1. Launch Instances
Nagios 4 System
PUBSUB
2. Configure Services per Role
3. Notify Interested Load Balancers
1
HTTP VoIP
Load Balancer Load Balancer
Web Web API API VoIP VoIP
Load Balancer Load Balancer Load Balancer Load Balancer Load Balancer Load Balancer
Database Database Database Media Layer Media Layer Media Layer
3
Privileged and Confidential
2

Pulling It All Together
Machine Startup/Shutdown
Boxconfig 1. Launch Instances
Nagios 4 System 5 PUBSUB
2. Configure Services per Role
6 3. Notify Interested Load Balancers
1
HTTP VoIP
Load Balancer Load Balancer
Web Web API API VoIP VoIP
Load Balancer Load Balancer Load Balancer Load Balancer Load Balancer Load Balancer
Database Database Database Media Layer Media Layer Media Layer
3
Privileged and Confidential
2

Pulling It All Together
Machine Startup/Shutdown
Boxconfig 1. Launch Instances
Nagios 4 System 5 PUBSUB
2. Configure Services per Role
6 3. Notify Interested Load Balancers
1
HTTP VoIP
Load Balancer Load Balancer
Web Web API API VoIP VoIP
Load Balancer Load Balancer Load Balancer
7 Load Balancer Load Balancer
7 Load Balancer
Database Database Database Media Layer Media Layer Media Layer
3
Privileged and Confidential
2

EC2 Learnings
Test “Roles” on Instance Sizes
Find optimal cost / performance tradeoff
Great for Load Testing
Spin up a test cluster, fire traffic, spin down...
Total cost: $5-10!
Great for Failure Testing
Hrm, what happens if I shoot this database...
terminateInstances()
Privileged and Confidential

Simplifying Telecom
Simple • Powerful • Pay-As-You-Go
Jeff Lawson
Co-Founder & CEO
twitter: @twilio
jeff@twilio.com
http://www.twilio.com