SIP to WinHow to make

phone calls over the internet.

by Rob Steadwww.robstead.co.uk

Quickly Covered

• Why use VoIP?• Topography• Some Terminology• Trixbox (a solution)• Trixbox demo• Some Issues• Useful links

Why user VoIP

• Cost effective– Cheap or free – hardware, software and calls– Can use ‘normal’ phones

• Flexible– Expandable– Great for remote offices and workers

Topography

Phone System

BT ExchangeBT Phone

Topography

ZAP

ZAP

Phone System

BT ExchangeBT Phone

Topography

ZAP

ZAP

Phone System

BT ExchangeBT Phone

The Internet

Topography

ZAP

ZAP

Phone System

BT ExchangeBT Phone

The Internet ISP Who Provides VoIP

Topography

ZAP

VoIP Server

BT Exchange

ZAP

BT Phone

The Internet ISP Who Provides VoIP

SIP

Topography

ZAP

VoIP Server

BT Exchange

ZAP

BT Phone

The Internet ISP Who Provides VoIP

SIP or IAX

Topography

ZAP

SIP

IAX

SIP

SIP

ZAP

VoIP Server

BT ExchangeBT Phone

The Internet ISP Who Provides VoIP

SIP or IAX

BT Phone

SIP Phone

BT Phone

BT Phone

Topography

ZAP

Softphone

Wi-Fi Phone

SIP

IAX

SIP

SIP

ZAP

VoIP Server

BT ExchangeBT Phone

The Internet ISP Who Provides VoIP

SIP or IAX

BT Phone

BT Phone

BT Phone

BT Phone

Topography

ZAP

Wi-Fi Phone

SIP

IAX

SIP

SIP

ZAP

VoIP Server

BT ExchangeBT Phone

The Internet ISP Who Provides VoIP

SIP or IAX

BT Phone

SIP Phone

BT Phone

BT Phone ISP Who Provides VoIP

ISP Who Provides VoIP

Softphone

Topography

ZAP

ENUM

Wi-Fi Phone

SIP

IAX

SIP

SIP

ZAP

VoIP ServerBT Exchange

BT Phone

The Internet ISP Who Provides VoIP

SIP or IAX

BT Phone

SIP Phone

BT Phone

BT Phone ISP Who Provides VoIP

ISP Who Provides VoIP

VoIP Server

Softphne

Some Terminology

• VoIP – Voice over Internet Protocol• SIP – Session Initiation Protocol – like http but for

VoIP• IAX – Inter-Asterisk Exchange – like SIP• Asterisk – Open Source VoIP system• FreePBX – Open Source switchboard• Trixbox – Bundled software package to create a VoIP

Server• Trunk – A SIP or IAX connection for making calls

Trixbox

• Available from www.trixbox.org as a downloadable CD image.

• Includes Asterisk, FreePBX and lots of over useful stuff.

Trixbox Demo

• Using my home test system

Some Issues

• Call quality – Use dedicated ADSL line and avoid Zap

• Phone system becomes more of an IT issue• Trixbox but getting better all the time but

issues some time• Initially complicated• Requires a little localisation for UK

Useful Link

• Trixbox – www.trixbox.org• Gradwell – www.gradwell.com• Voipon – www.voipon.co.uk• Voiptalk – www.voiptalk.co.uk• Zoiper – www.zoiper.com• Bria – www.counterpath.net