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

• 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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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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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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Demo

• Boot from a Battery
• Make a phone call
• telnet in
• GUI
• NAND flash

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Questions?

• For more information
• rowetel.com/ucasterisk

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Notes

• demo? Maybe ask Mike, Idea battery powered, or
  photo of Alberto's miniPC to compare. New GUI?
  Hook up battery in front of them and boot?
  Telnet in?intro some sticky new ideas and geeky
  experiences