How to Build an Embedded Asterisk IPPBX rowetel'comucasterisk

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How to Build an Embedded Asterisk
IP-PBXrowetel.com/ucasterisk
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Contents

• Free Telephony Project
• Why Embedded Asterisk
• Motivation
• Open Hardware
• Open Hardware Hacking
• Credits
• Products
• Demo

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Free Telephony Project 1

• many people working in open software
• we are working in open hardware
• professional telephony hardware designs
• that we give away
• to improve the world a little

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Free Telephony Project 2

• designs can be copied modified, re-used without
  restriction
• we encourage cloning of our products
• trend functionality shifting from hardware to
  (free) software
• trend total system costs constantly dropping

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Free Telephony Project 3

• falling hardware costs are a good thing
  (especially for the developing world)
• so rather than protecting IP we leverage these
  trends
• by giving away free hardware designs
• and encouraging cloning!

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Why Free Telephony Project?

• Hardware designs are free as in speech
• Use FOSS and Open Hardware to drive system costs
  to 0
• Lower the cost of telephony for everyone on the
  planet
• A phone call should be a human right, not a
  privilege

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Why Embedded Asterisk

• Small size (DSL router)
• Low power 3W (battery, solar)!
• No moving parts (fans or disks)
• Quiet
• Reliability (parts count, connectors)
• Low cost (few hundred )
• Just plain cool!

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IP-PBX and Asterisk

• A open source PABX (PBX) that can route calls
  between the PSTN and VOIP
• Usual FOSS advantages low cost and open
• VOIP experiencing massive growth
• Primary sponsor Digium but many contributors
• Hence alternatives such as FreeSwitch,
  CallWeaver, etc, etc

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Introduction

• Typical installation x86 PC plus PCI card to
  connect to the telephone lines/telephones.
• Paradigm shift away from x86/PCI cards
• History Embedded IP-only and no DSP (Echo
  cancellation and codecs not possible)
• Analog Devices Blackfin Processor has challenged
  this paradigm!

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Blackfin Processor

• A powerful DSP (1 GMAC)
• AND runs uClinux
• Breaks the two processor (host/DSP) paradigm
• Low cost (5 - 15 each)
• Well supported by vendor and community
• Open hardware and software

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IP-PBX Hardware 101
Host PC
PCI Card
PCI Bridge
FXO Port
Asterisk
Device Driver
x86 CPU
DSP hardware
Ethernet Card
FXS Port
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IP-PBX Hardware 101
Embedded PBX
FXO Port
Blackfin CPU
Asterisk
DSP software
Device Driver
FXS Port
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IP-PBX Hardware 101

• Many redundant parts removed
• Lower cost
• Smaller size
• Lower power
• Enhanced reliability
• Dont need hardware DSP Blackfin CPU is a DSP

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Challenges

• Complex development environment
• Cross compiler tool-chain
• Customized kernel and apps
• Learning Curve
• Low memory 64MB
• uClinux (offset by partial MMU)
• Care and feeding of the cache

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Motivation 1

• Various motivations across the people and
  companies involved in the project.
• Obvious business potential in a 200 IP-PBX with
  multiple ports.
• Enabler for service models.
• My motivation is Social Geeky rather than
  Business.

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Motivation 2

• I like building stuff
• Would like to use my hardware/DSP skills to
  improve the world a little
• Open software like Linux and Asterisk has been a
  great thing for the World.
• Craig Newmark (Craigslist) Nerd values Get
  yourself comfortable, then do something fun to
  change the world a little

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Open Hardware 1

• reference designs that anyone is free to copy,
  re-use, modify
• CAD files, prototypes
• differences from open software
• atoms cost more than bits
• you need a factory

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Open Hardware 2

• many advantages over closed development
• similar to open software
• many eyes
• low bug count
• dramatic reduction in RD cost and time

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Open Hardware 3

• CVS/SVN for version control of designs
• re-using hardware building blocks
• helping each other get strange parts
• blog instead of log book share experience
• chat to help debug hardware

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Open Hardware 4

• normal hardware costs include 70 overhead
• exciting new business models, e.g. OLPC
• dramatic price reductions
• local manufacture
• customisation, localisation, e.g. solar, wireless

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How to Hack Telephony Hardware in Linux

• Schematic Entry (gschem)
• PCB Design (PCB)
• Verilog HDL (Icarus)

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Design Process Flow
Design Schematics (gschem)
Write Verilog Code (Icarus)
Design PCBs (PCB)
Assemble Prototype Hardware
Debug and Test Hardware
Port Asterisk to Blackfin (gcc)
Integrate and Test system
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gschem Schematic Entry
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Analog Hardware Example
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Hardware Hacking is Getting Easier!!

• Build sophisticated surface mount circuits.
• Order strange parts on-line e.g. Digikey
• Prototype PCB costs dropping
• Stereo Microscope soldering tools lt 500
• Open hardware designs
• Free CAD tools
• Help from on-line communities

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Open Hardware IP-PBX Products

• IP04 4-port Analog IP-PBX (production)
• IP08 8-port Analog IP-PBX (prototype)
• E1/T1 PRI-Appliance (prototype)
• BRI-Appliance (prototype)

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Case Study - IP04

• Switches analog and VoIP calls
• fanless, low power (5W), rugged, compact
• open hardware and software
• easy to customise, e.g. simple UI
• potential for very low cost (100), compared to
  2,000 retail for similar products
• stable but not feature complete (CID, GUI)

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Case Study IP04
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PRI Appliance (Astfin Team)
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BRI Appliance (Astfin team)
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'Free Phone Call

• between Adelaide and Beijing using two IP04's
• open hardware design
• designed with open CAD software
• running uClinux and Asterisk
• using VOIP (0 call cost)
• Freest phone call ever?

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Demo

• Boots from a Battery
• phone call
• telnet, asterisk CLI
• GUI

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Credits

• In no particular order
• Atcom (China) for putting the IP04 into mass
  production
• Astfin team for developing build system, PRI and
  BRI-ISDN hardware
• Analog Devices for Blackfin and great uClinux
  support
• Linux and Asterisk communities
• Many others who contributed (e.g. drivers,
  software fixes)

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Questions?

• For more information
• rowetel.com/ucasterisk