VOIP Troubleshooting using ClearSight Analyzer

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VOIP Troubleshooting using ClearSight Analyzer
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Agenda

• ClearSight Company Overview
• ClearSight Analyzer Overview
• VoIP Analysis with ClearSight Analyzer
• Signaling Protocols
• Media Protocols
• Hands on Examples
• Q A

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ClearSight Company Overview

• Founded March, 2001 as AppDancer
• Founders created Sniffer Pro
• Name/Product Launch October, 2003
• HQ San Mateo, California
• Fiscal 2004
• 6 Figure Operating Income, on
• Mid-7 Figure Revenues
• Worldwide Partnership - Spirent Communications
• Received Key Editorial Accolades

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ClearSight Analyzer Overview
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Traditional Network Analyzers

• Use The Bottom-Up Approach
• Troubleshooting Based Upon Raw Packets Not
  Necessarily Real-Time
• Focus on lower-layer elements
• Physical Errors
• Host Tables
• Top Talkers
• Utilization
• Neither Intuitive Nor Easy!

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Traditional Analyzer GUI
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The ClearSight View
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Bridging The Gap

• ClearSights Analyzer Enhances the IT
  Professionals Ability To
• Quickly Identify Trends, Issues and Problems
• Determine if Theyre
• Physical
• Environmental
• User - Related
• Facilitates Deployment of Optimum Resource Levels

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Product Portfolio
ClearSight Analyzer
10 Gigabit
1 Gigabit
Distributed
Hardware Performance
Full Duplex
Software-Only
Special Edition
NEM
Operator
Enterprise
SMB
Segment Appeal
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VoIP Technology
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VoIP Technology
(The conventional telephone)
PBX
PBX
PSTN
Fixed-line telephone
Fixed-line telephone
Difficult to Troubleshoot
(VoIP)
PBX/GW
PBX/GW
IP network
Fixed-line telephone
Fixed-line telephone
IP phone
IP phone
IP packet
VoIP (Voice over IP) PBX (Private Branch
Exchange) GW (Gate Way) PSTN (Public Switched
Telephone Network)
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VoIP Signaling Protocols

• The protocols which manage setup, transfer,
  maintenance, and disconnect of a call in an IP
  telephone
• Protocols which exchange information on terminal
  capabilities and/or CODECs
• Typical VoIP signaling protocols
• SIP
• H.323
• Cisco Skinny
• MGCP
• MEGACO

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VoIP Protocol Stack (SIP example)
Media protocols
Signaling protocols
SDP (Session Description Protocol)
Movie H.26x
Voice G.7xx
SIP (Session Initiation Protocol)
RTCP
RTP
UDP
UDP(TCP)
Network Layer(IP)
Data Link Layer
Physical Layer
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ClearSight Creates a Call List

• ClearSight creates a group of associated protocol
  sessions for each call
• Also automatically creates a call list

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SIP Request Method Response
ltMethodgt INVITE Used to initiate the
session ACK Used as a confirmation that the
final response has been received BYE Used to
terminate a session REGISTERUsed by a user-agent
client to log in and register its address
with a SIP server OPTIONSQueries
a server as to its capabilities Cancel Used to
terminate a pending
ltResponsegt 1xx Provisional 2xx Success 3xx
Redirection 4xx Request Failure 5xx Server
Failure 6xx Global Failure
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SIP Ladder Display
lt Direct communication between two terminals gt
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SIP Server Example
ltCommunication through a SIP servergt
SIP
SIP
SIP server 172.17.0.20
RTP
IP phone [phone]
IP phone [phone]
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SIP Ladder Display
lt Communication through a SIP servergt
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Media Protocols RTP RTCP
RTP
Voice ( A lt- B )
RTCP
RTP
Voice ( B -gt A )
RTCP
RTP
Video( A lt- B )
A
RTCP
B
RTP
Video ( B -gt A )
RTCP
?RTP (real time transport protocol)RFC1889 RTP is
designed to provide end-to-end network transport
functions for applications transmitting real-time
data, such as audio, video, or simulation data,
over multicast or unicast network services.
?RTCP (RTP control protocol) RFC1889 RTCP is
companion protocol of RTP. This is used for
quality feedback of the voice packets.
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RTP Flow Statistics
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Major Elements of Voice Quality

• Packet loss
• lt 1 Negligible impact
• 3-5 Momentary pauses in conversations
• 10 Considerable deterioration of quality
• gt 20 Difficult to carry on any conversation
• Latency
• gt 25ms Requires echo cancellation
• lt 150ms Typically no discernable problem
• 150-400ms Although the voice quality of user
  application is affected, use is
  possible if you understand it.
• gt 400 ms Unsuitable for most applications.
• Jitter
• Echo

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Voice Quality Evaluation Method

• The subjective evaluation method
• MOS (Mean Opinion Score) ITU-T recommendation
  P.800
• The objective evaluation method using Perception
  model
• PSQM (Perceptual Speech Quality
  Measurement) ITU-T recommendation
• PAMS (Perceptual Analysis Measurement
  System) British telecom
• PESQ (Perceptual Evaluation of Speech
  Quality) ITU-T recommendation P.862
• The objective evaluation method using Calculation
  model
• R-Value (E-Model) ITU-T recommendation G.107

It Talks
It Talks
IP Network
Intermediate device
Intermediate device
Phone
Phone
Intermediate device
IP Network
Intermediate device
Voice File
Original Voice Signal
Deteriorated Voice Signal
Test Equipment
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Scoring R-Value and MOS
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VoIP Analysiswith ClearSight Analyzer
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ClearSight VoIP Advantages

• Multiple Physical Segment Correlation (Real-time
  and post analysis)
• The next generation trouble-shooting tool for
  data and voice convergence
• Real-time VoIP playback including distributed
  remote
• The only trouble-shooting tool supporting video
  playback
• Extensive playback CODEC support
• Real time QOS, VoIP alarms and triggers
• Integrated VoIP SLA
• Reporting VoIP Summary, SLA Trending, and
  Per-conversation QOS Report
• VoIP Application level filter Eg. phone number
• VoIP/WiFi QOS analysis over AP and WiFi LAN switch

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VoIP QoS Report
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VoIP Playback

• ClearSight Supported CODECs for playback
• Audio CODECsG711(U-law / A-law), G.729, G.723,
  G.722, etc.
• Video CODECsJPEG(411, 422, 111), H.263 Mode A/B

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VoIP Reporter

• ClearSight Supported CODECs for playback
• Audio CODECsG711(U-law / A-law), G.729, G.723,
  G.722, etc.
• Video CODECsJPEG(411, 422, 111), H.263 Mode A/B

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ClearSight AnalyzerHands on Examples
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Solving a Typical VoIP Problem
SIP Phones can ring each other, however, Phone
A?B No problem Phone B?A I cant hear you
! Q. WHY ?
I cant hear anything !
I can hear you.
Ring!!
OK!
NG!
Phone B
Ring!!
OK!
OK!
Phone B
Phone A
Phone A
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VoIP System
Phone B ?10.0.2.10?
SIP Server 192.168.0.3
L3 Switch
L3 Switch
ClearSight
Hub
C
Cloud
Phone A ?10.0.0.10?
Router
Router
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Signaling Flow
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ClearSight solution for VoIP over WLAN Switch
SIP Server
WLAN Switch- AirSpace- Aruba Etc.
ClearSight
WLAN packets over Ethernet encapsulated with
special header

• Voice quality analysys
• VoIP signaling analysis
• Roaming analysis

HUB
AP1
AP2
Initial RTP flow
RTP flow after roaming
move
WLAN SIP phone 1
WLAN SIP phone 2
WLAN SIP phone 2
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AireSpace Decode Sample packets between AP and
WLAN Switch
LWAPP Encapsulation header
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VoIP ladder display of WLAN VoIP phone traffic
traffic between AP and WLAN Switch
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The Next Generation VoIP Trouble-shooting Tool