Linuxsa 2007 Embedded Asterisk

8/8/2019 Linuxsa 2007 Embedded Asterisk

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How to Build an Embedded

Asterisk IP-PBX


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Topics

IP-PBX and Asterisk

Why Embedded? IP PBX Hardware 101

Free Telephony Project and Open Hardware

Status The Future

Opportunities


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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 sponser 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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Why Embedded Small size (DSL router)

Low power < 5W (battery, solar)! No moving parts (fans or disks)

Quiet

Reliability (parts count, connectors) Low cost (a few hundred $ street)

Just plain cool!


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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

PCI

Bridge

FXO

Port

x86 CPU DSPhardware

Asterisk

EthernetCard

FXS Port

Host PC PCI Card

Device

Driver


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IP-PBX Hardware 101

FXO

Port

Blackfin

CPU

DSPsoftware

Asterisk

DeviceDriver

FXS Port

Embedded PBX


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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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Who is working on Blackfin

Asterisk? Several individuals and companies working

on Blackfin Telephony products.

Expect to see many embedded Telephony

products in the near future

This presentation focuses on the activities of

the Free Telephony Project


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FreeT

elephony Project Goals Build a completely open embedded

telephony platform.

Hardware designs are open.

Full design and manufacture information

available for download.

Schematics, PCB layouts, HDL code, unit tests


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Motivation 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 I like building stuff

Would like to use my hardware/DSP skills

to improve the world a little

Open software like Linux and Asterisk hasbeen a great thing for the World.

Craig Newmark (Craigslist) : Nerd valuesGet yourself comfortable, then dosomething fun to change the world a little


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Open Hardware The designs are free as in speech

A community exists that are sharing designs

and helping each other.

Build better hardware faster using open

development models.

Opportunities for small business.

Its working!


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Hardware Projects (so far) BlackfinOne DSP Motherboard (mature)

4-8 port FXO/FXS Analog (mature)

E1/T1(prototype hardware and driver)

BRI-ISDN (stalled)

IP04 $100 IP-PBX (mature)


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How to HackTelephony

Hardware in Linux

Schematic Entry (gschem) PCB Design (PCB)

Verilog HDL (Icarus)


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Port Asterisk

to Blackfin

(gcc)

Design

Schematics

(gschem)

Design PCBs

(PCB)

Assemble

Prototype

Hardware

Debug and

Test Hardware

Write Verilog

Code (Icarus)

Integrate and

Test system

Design Process Flow


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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 < $500

Open hardware designs

Free CAD tools Help from on-line communities


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Status

Port Asterisk

to Blackfin

Develop DSPMotherboard

Develop Analog

Hardware

Production

Engineering

Volume

Manufacture

IP04

Prototypes

Port driver to

Blackfin

Sep 2005 Sep 2006 Jan 2007

May 2007

Q3 2007


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Performance 500 MIPs Available (1 GMACs)

G729A (8 MIPs)

Speex (15-30 MIPs)

Simultaneous SIP Calls (approx 50)

Echo Can

Depends on tail

12-24 ports depending on tail


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Opportunities Business

Individuals

End Users


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Opportunities for Business Massive Differentiation

Cost/Margin advantages

New products we havent even thought of:

Asterisk ATA or fax

Asterisk in an very smart IP-phone

T1 IP-PBX in an ATA form factor for $200

?


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Opportunities for Individuals Its open. All of it. Hardware and software.

Even the CAD tools!

Exciting project in early stages

Chance to really contribute

Its very different from x86/PCI

Helped needed: Hardware, software,

Asterisk config


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Opportunities for End Users Lower end user cost a $300 (street) 4-port

IP-PBX in 2008?

IP-PBX functionality in the home ratherthan current ATA.

Bring telephony to developing countries.

Small, fan-less lets you reach markets likeSOHO that dont want a PC for their phonesystem.


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Getting Started Buy a Blackfin STAMP Card ($226)

Buy a 2 FXO 2 FXS port Analog Starter Kit

($299)

Start Hacking


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Questions?

For more information

http://rowetel.com/ucasterisk

geda.seul.orgblackfin.uclinux.org

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