Testing SIP Services Over IP

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• Testing SIP Services Over IP

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Agenda

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

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• Test Equipment Requirements

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SIP Testing the basics

• Call simulation
• Call monitoring
• Signaling analysis
• Media analysis
• Conformance testing
• Load (stress) generation

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Advanced SIP Testing

• Advanced testing
• Benchmarking
• Performance
• Media degradation
• Envelope determination
• In terms of a large network

• For complex scenarios
• Many users
• Many call flows
• Different codecs
• Different networking configuration
• NAT, Firewall

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Stress Testing??

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

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Stress Testing!

• Not just number of calls
• Emulate a network wide environment
• Large number of users
• Many network elements (IPs)
• Emulate NAT
• Excessive call load
• Many profiles / scenarios
• Many different services

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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
• How are new / existing calls affected?
• Is the media degraded?

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Stress Factors

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

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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
• different signaling and media parameters for each

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Registration Rate

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

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Advanced Testing Requirements (1)

• Multiple users
• 100,000s UACs
• Configurable groups each with different behavior
  profiles
• Multiple IPs
• 1000s of IPs - both media and signaling
• Multiple MACs
• Multiple VLANs

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Advanced Testing Requirements -- 2

• Full SIP message customization
• Video generation
• DTMF generation
• Different call flows
• Hold, Consultation Hold, Music on Hold, 3-way
  Conference, Call redirect, Call reject
• Erroneous flows

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Key Traffic Generation Measurements

• Session success rates and GoS
• SIP method count and response code
• Registration history
• Presence and IM message statistics
• Incoming and outgoing RTP stream counters

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• Real Life Examples

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Common pitfalls

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

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Network Model Simple Test Lab

• Test Environment
• Multi-service solution
• Multi-technology VoIP PSTN

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Network Model Simple Test Lab (cont.)

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

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Testing Options

• Performance - under different levels of stress
• Signaling and media quality evaluation
• Call handling
• Media degradation
• Interoperability
• Different codec models
• PSTN and VoIP devices
• Reliability
• Quality evaluation
• Stability testing

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Firewall, SBC, CSCF Testing
Call Analysis
Call Analysis
Test bed 1
Test bed 2
Soft-Switch
Soft-Switch
Public IP
Session Boarder Controller
Session Boarder Controller
SIP Stress Generator
SIP Stress Generator
SIP Stress Generator
SP1
SP2

• Load scenarios
• BHCA 1,000,000s per hour
• CPS hundreds to thousands
• Concurrent calls gt 100,000s

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Firewall, SBC CSCF Test Lab

• SIP Stress Generation requirements
• Different levels of stress
• Different services
• Different media
• Different call flows
• QoS analysis
• Voice quality
• Transport

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Firewall, SBC CSCF Testing Needs

• QoS
• Delays, Jitter, Packet loss, MOS
• Stability (network elements / services)
• Benchmarking and comparisons

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Simultaneous test bed operation
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Elegant solution