sip interoperability testing alan percy director of business development audiocodes, inc....
TRANSCRIPT
SIP Interoperability Testing
Alan PercyDirector of Business
DevelopmentAudioCodes, [email protected] #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, [email protected] #822
Come and meet us at the Keynote!
Thursday @ 5:15