SIP Interoperability Testing Alan Percy Director of Business Development AudioCodes, Inc. Booth #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 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 quality 3.Provisioning and Management Media Control Provisioning And 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: Published Interop Certification

What affects voice quality?

Measuring Quality - ETSI Test Setup

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 Percy Director of Business Development AudioCodes, Inc. Booth #822 Come and meet us at the Keynote! 5:15