SIP Interoperability Testing

Alan PercyDirector of Business

DevelopmentAudioCodes, Inc.Alan.percy@audiocodes.comBooth #822

AudioCodes – A VoIP Leader 13 Years of Operation Focusing on VoIP Media

Gateway & Media Server Technology Field proven technology: Over 12 Million

Channels shipped to over 100 Countries Enabling the VoIP leading OEM’s and TEM’s Key originator of ITU G.723.1 standard for VoIP Leader in Innovation and Density of VoIP

Solutions Financially strong and stable

What is Interoperability?

“Achieving a known level of compatibility between two devices”

The “Basics”

Easy to get started Plenty of reference

materials and software

Basic call establishment and disconnect

The “Real Work”

All the other things needed to build complete market-ready solution

Three Planes

1. Control Plane – SIP Signaling and PSTN interfaces

2. Media Plane – Coders and voice quality3. Provisioning and Management

Media

Control

ProvisioningAnd

Management

PSTN Signaling

Analog FXS and FXO

Digital T1 / E1 / J1 CAS vs. ISDN SS7

Caller-ID and User-to-User Information

DTMF Relay

Different ways to transport DTMF In-band (G.711) RFC 2833 SIP INFO methods …

Call Transfer

Re-INVITE and REFER PSTN Transfers

Two B Channel Transfers (TBCT) Release Link Transfers (RLT) Flash-hook (analog)

Supervised and Blind

Message Waiting

Analog phones FSK LED Neon Stutter Dial-tone

Call Progress Detection

How does the application detect the success of outbound calls?

Can it detect? Busy No Answer Answer by a human SIT Tones Answering Machine

How does it relay the results?

Emulation

Sometimes to win business, you need to emulate another vendor’s equipment

Need to emulate: Not only what they do! But, they don’t do!

Media Plane

What coders are supported? Wireline and wireless coders? Bit rates and frame sizes? T.38 Fax?

Early media and ring-back?

Provisioning and Management

Growing Issue More and more software applications are

embracing

“Plug-n-play” Auto-discovery Remote configuration and software load

How is Basic Testing Done?

Getting Started - “The Basics” SIPit, SIMPLEt or other public interoperability

events 30 Minutes at most for each “test” Only scratch the surface

Just “the tip of the iceberg”

How is Advanced Testing Done?

Advanced Testing “The Real Work” Establish a test plan

What is the goal?

Depends on more than one component Interoperability Test Bench Establish technical relationships

Software Partners Other Technology Partners

Voice Quality Testing

Target: PublishedInterop

Certification

What affects voice quality?

Measuring Quality - ETSI Test Setup

G a t e w a y

I P

E 1

N I S T N e t

P a c k e t M O N I T O R

E 1

P a c k e t L o s s D e l a y

O u t p u t

H E A D a c o u s t i c s T e s t S y s t e m AA CC QQ UU AA

I n p u t

G a t e w a y I P I P

I S D N D S S 1 I S D N D S S 1

P B X

Measuring Quality – RTCP XR

Real Time Control Protocol – Extended Reports Embedded measurement tool Measuring Quality During the Call

Packet Loss Delay Signal Quality …

Call Quality – MOS and “R” Factor Reported in RTCP, SDP or via SNMP

Improving Voice Quality

Techniques vendors use to maximize quality: Dynamic Jitter Buffer

Adjusting to ever-changing network conditions

Packet loss concealment All coders, including G.711

Echo cancellation algorithms “Double Speak” VAD and CNG algorithms Extensive field and lab testing

Ongoing Testing?

Easy to forget: Maintenance Ongoing improvements/enhancements

“We never expected that”

Revisions of software and hardware Recertification / retesting

Summary

Showed what is below the surface

Understand the complexity of full interoperability testing

Helped you avoid major navigational errors “But, captain….”

Thanks

Alan PercyDirector of Business

DevelopmentAudioCodes, Inc.Alan.percy@audiocodes.comBooth #822

Come and meet us at the Keynote!

Thursday @ 5:15