Testing Large Scale SIP Networks Ofir Michael Director

Testing Large Scale SIP Networks Ofir Michael Director Vo. IP technology, RADCOM. ofirm@radcom. com

Agenda • SIP testing – advanced scenarios • SIP testing - Real Life Examples

Test Equipment Requirements

SIP Testing – the basics • Call simulation • Call monitoring o o Signaling analysis Media analysis • Conformance testing • Load (stress) generation

Advanced SIP Testing • Advanced testing o o • For complex scenarios: Benchmarking Performance Media degradation Envelope determination o o o • In terms of a large network… Many users Many call flows Different codecs Different networking configuration NAT, Firewall…

Stress Testing? ? • Aimed at determining the operational envelope: o o o Network elements Service Certain concept / design • Why stress test: o o Vendors: wants to determine performance figures before shipping Service Providers: wants to find the problems in the lab

Stress Testing! Not just “number of calls” • Emulate a network wide environment: o o o Large number of users Many network elements (IPs) Emulate NAT • Excessive call load • Many profiles / scenarios • Many different services

What are we looking for Predicting the element behavior in real life: • How does the UUT (network element / service) behave in real life (=stress…) • Where is the “breaking point” • What happens at the “breaking point” o How are new / existing calls affected? o Is the media degraded?

Stress Factors • Basic call flows (signaling) • RTP streams • Media type (Video, Audio) • Advanced call flows • SIP services

Signaling Stress Requirements • Generate and respond to SIP service requests • Simulate User Agent Client / Server communication procedures (RFC 3261) • Emulate behavior of one or many SIP phones o different signaling and media parameters for each

Registration Rate • True emulation of user behaviour o Generate calls only when registered • Mega-blast generation of registration events • Full configuration of SIP registration procedures o Mimic real user behaviour

Advanced Testing Requirements (1) • Multiple users o 100, 000’s UACs o Configurable groups each with different behavior profiles • Multiple IPs o 1000 s of IPs - both media and signaling • Multiple MACs • Multiple VLANs

Advanced Testing Requirements -- 2 • Full SIP message customization • Video generation • DTMF generation • Different call flows: o Hold, Consultation Hold, Music on Hold, 3 -way Conference, Call redirect, Call reject… • Erroneous flows

Key Traffic Generation Measurements • Session success rates and Go. S • SIP method count and response code • Registration history • Presence and IM message statistics • Incoming and outgoing RTP stream counters

Real Life Examples

Common pitfalls • Registration properties o Tendency to forget the credentials • Registration rates o o Initially takes too long Server will not withstand load • Non-standard flows • Test signaling & media simultaneously

Network Model: Simple Test Lab Analog call generator Call Analysis IP / ATM / FR Core 2 UUT SIP Stress Generat or Call Analysis Core 1 UUT Test Environment: • Multi-service solution • Multi-technology: Vo. IP & PSTN SIP Stress Generat or

Network Model: Simple Test Lab (cont. ) • SIP Stress Generator: o o Generate different levels of stress including RTP Voice and video simulation • Call Analysis: o o o Signaling and media analysis Voice quality (intrusive, non-intrusive and subjective) RTP transport streams • Analog Call Generator o o Connect to PSTN interfaces Measure voice quality, voice distortion

Testing Options • Performance - under different levels of stress: o o o Signaling and media quality evaluation Call handling Media degradation • Interoperability o o Different codec models PSTN and Vo. IP devices • Reliability o o Quality evaluation Stability testing

Firewall, SBC, CSCF Testing Call Analysis Test bed 1 Soft. Switch Test bed 2 Soft. Switch Public IP Stress Generat or Session Boarder Controller SIP Stress Generat or SP 1 • Load scenarios o o o SP 2 BHCA – 1, 000 s per hour CPS – hundreds to thousands Concurrent calls > 100, 000 s SIP Stress Generat or

Firewall, SBC & CSCF: Test Lab • SIP Stress Generation requirements: o Different levels of stress o Different services o Different media o Different call flows • Qo. S analysis: o Voice quality o Transport

Firewall, SBC & CSCF: Testing Needs • Qo. S o Delays, Jitter, Packet loss, MOS • Stability (network elements / services) • Benchmarking and comparisons

Simultaneous test bed operation

Elegant solution