© WildPackets, Inc.#wp_wireless Wireless Network Analysis 101 - VoFi
Administration
• All callers are on mute
‒ If you have problems, please let us know via the Chat window
• There will be Q&A
‒ Feel free to type a question at any time
• Slides and recording will be available
‒ Notification within 48 hours via a follow-up email
2

Agenda
• Why VoFi? Why now?
• Collecting data for VoFi analysis
• Assessing the WLAN landscape for VoFi
• Using VoIP metrics with VoFi
• VoIP/VoFi – one more call and you’re over the cliff
• Demo – anatomy of a VoFi call
• Key wireless factors in VoFi quality
• Corporate overview
• Product line overview
3

Why VoFi? Why Now?
4

Why VoFi?
Quality Convenience Cost

Why Now?
• Smart phones support 802.11 - period
• VoFi systems have already found wide acceptance in
some areas: manufacturing, medical, retail
• The Wi-Fi alliance supports 2 certification programs:
‒ Voice-Enterprise: 44 certified products
‒ Voice Personal: 69 certified products
“802.11ac is being pushed into smart phones by key carriers’
device requirements that are in sync with 802.11ac hotspot
plans for more robust Wi-Fi offloading.” ABI Research

Collecting Data for VoFi Analysis
7

Flexible Data Collection - Portable
• Network analysis software (OmniPeek) with
supported NIC
‒ 802.11a/b/g/n USB adapter
‒ VoIP, VoFi, full Expert Analysis
‒ Simultaneous Wired and Wireless Capture
• Multi-channel aggregation
‒ 802.11a/b/g/n USB adapters
‒ USB hub
‒ Powered USB hub for captures on 3 or more channels

Remote Captures with OmniEngine
Remote Software
Probe for 24x7
Operation
Using USB Adapters Using APs
RemotePcap
Custom
Remote
Adapters

Assessing the Wireless Landscape
11

It’s All One Network
12

And It’s Wireless and Wired
13

Using VoIP Metrics with VoFi
14

Key RTP (VoIP/VoFi) Issues
CAMP IT Pinpointing the Problem 15
Jitter
Latency
Packet
Loss

Assessing the Monster's Impact
• While traditional network applications are very tolerant of jitter,
latency, and even some degree of packet loss, VoIP/Video/VoFi
are very sensitive to these troubles
• Levels of jitter, latency, and packet loss that would be easily
tolerated on a data network can be devastating on a converged
VoIP/Video network
• Pre- and post-deployment network assessments are critical
‒ You must understand your network’s ability to accommodate VoIP
• Current latency, jitter, and packet loss
• QoS capabilities
• Current bandwidth utilization (is there any room for VoIP)
‒ You must maintain a constant vigil after deployment to watch for
imminent troubles

Latency
Queue Latency &
Decision Latency
Network
Propagation
Delay
Encoding / Decoding
Compression / Decompression
Jitter Buffer Latency
0 ms
100 ms
200 ms
300 ms
400 ms
500 ms
600 ms
700 ms
800
ms
The ITU
recommends a
maximum one-
way delay of
150 ms for
VoIP

Latency's Effects
• Talkover
‒ Occurs when excessive latency delays audio
– Conversation cadence is not natural or comfortable
– Callers feel as if they must “push to talk” or say “over” to control the
conversation
• Echo
‒ The speaker’s voice feeds back into the listener’s microphone
‒ The speaker then hears his own voice returning from the listener’s end,
but delayed due to latency
‒ Most callers find it difficult to maintain normal speech when echo delay
is prolonged
‒ Some VoIP systems attempt to cancel echo, but are not always
successful
High latency may also cause additional troubles such as loss of
synchronization between audio and video for multimedia sessions.

Jitter
• Jitter is the variance in packet delivery intervals to the listener
• Jitter buffer adds additional delay to voice reaching the ear piece in
case other packets need to catch up
• Packets delayed too long in the network are not allowed to enter the
jitter buffer
Packets delayed more than the buffer delay
(100 ms as an example) are dropped
. . .. .. . . ........
......
Packets are buffered and
delayed at the Receiver
The “jitter” buffer releases
a G.711 packet every 20 ms
A G.711 packet sent
every 20 ms
Packet jitter and drops
31
2
4

Jitter's Effects
• Jitter causes weird “sound effects” that vary with
jitter severity and environmental factors
• Examples include:
‒ Static
‒ Stuttering or uneven audio – abnormal speech rhythm
‒ For multimedia systems, video may be “jerky” or irregular
• If jitter levels are high, packet loss can result
‒ In some cases, severe jitter may sound similar to packet loss,
even if no packets are actually dropped

Packet Loss and Effects
• Most commonly caused by:
‒ Packet dropped due to physical layer corruption
‒ Congestion without adequate QoS provisions
‒ Jitter buffer discards due to excessive latency
• Causes missing sounds, syllables, words, or phrases
‒ DSP algorithms may compensate for up to 30 ms of missing
data
‒ More than 30 ms of missing audio (e.g. 2 RTP packets for
G.711) is noticeable by listeners
• Losing only a few packets can still be very noticeable
‒ Loss rates ≥ 2% will have a strong impact on quality
‒ Losses of 5 – 10% make calls all but intolerable
‒ Bursty periods of packet loss are worse than more dispersed
loss

Quality Scoring for VoIP
• Mean Opinion Score (MOS) – several flavors
‒ Algorithmic simulation of subjective audio assessment
‒ Most commonly used varieties are MOS-LQ (listening quality)
and MOS-CQ (conversational quality)
‒ Possible range of 1 (poor) to 5 (excellent)
‒ Maximum possible MOS = 4.4 with G.711
‒ Typical range in most networks is 3.5 – 4.2
• R-Factor – several flavors
‒ Based on latency, jitter, packet loss, bit rate, and signal-to-noise
ratio, codec effects (for low bit-rate codecs)
• The ITU algorithms consider about 20 quality inputs
‒ Possible range of 0 (poor) to 100 (excellent)
‒ Provides LQ, CQ, and other score variants

Crunching the Voice Score
OmniPeek does the hard part…
… so you can see the bottom line
Source: ITU Recommendation G.108 – E-Model Guidelines

A Picture is Worth a 1000 Words
• A graph of latency, jitter, or
packet loss can speak volumes
about network health, either for
proactive or reactive
troubleshooting
• Overlaying graphs with
network utilization or total
throughput can reveal even
more about the causes of VoIP
troubles
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
4.50
5.00
8:45
9:15
9:45
10:15
10:45
11:15
11:45
12:15
12:45
13:15
13:45
14:15
14:45
15:15
15:45
16:15
16:45
17:15
MeanOpinionScore
Time
MOS

Video vs. VoIP
• Video is more difficult to manage than voice
‒ more “bursty”
‒ bandwidth intensive
‒ more sensitive to latency, jitter, and packet loss
‒ Includes several different applications with distinct demands
• Video packets vary greatly in size
• Tremendously compressed amount of visual information (99%
compression ratio typical)
• One HD video stream can consume up to 20Mbps of bandwidth
• Video apps require millisecond-level network service recovery

One More Call and You're over the
Cliff

The Impact of "Just One More Call"
• Although a network link may be able to support a
number of concurrent calls, one additional call is
often enough to cause quality problems…
x1113
x2111
x1112
x1111
1st Call
2nd Call
3rd Call
x2112
x2113
Example: The WAN can support 2 simultaneous calls.
What happens when a third call is attempted???
Call #3 Causes Poor Quality for ALL Calls

Demo: Anatomy of a VoFi Call

Packet-by-Packet
VoFi Call
Wired VoIP Call

Just the Stats, Mam

Key WLAN Factors for VoFi

Additional Factors to Consider
• Interference
• CRCs vs. retransmissions
• QoS (WMM)
• Roaming
• AP load
32

Quantitative Interference Impacts on VoFi
Source: Farpoint Group

Quantitative Interference Impacts on VidFi
Source: Farpoint Group

CRCs vs. Retransmissions
35

Ready for QoS/WMM?
• QoS provisions are based on the “weakest link”
concept
‒ If any device in a data path does not support QoS, then media
streams will not be afforded the preference they require for good
performance
• Pre-deployment assessment must ensure that ALL
devices can recognize and respond to QoS
parameters in packet headers
‒ Switches, routers, firewalls, proxies, and any other devices that
touch RTP packets must be “VoIP-friendly”

Client Roaming
• Occurs when a handset moves out of range of one
AP and into another – typically changes channel
• Client roaming = Fast Basic Service Set (BSS)
Transition
• Legacy systems deal poorly with roaming – they’re
not fast enough
• Standards help:
‒ 802.11i with Opportunistic Key Caching (OKC)
‒ 802.11r-2008 – Fast BSS Transition
‒ 802.11k-2008 – Radio Resource Measurement of WLANs

Roaming in Action
• Multichannel Analysis
• Roaming Analysis
‒ Detailed and accurate
measurements from many
perspectives
• End-user and device
manufacturer
‒ Summary data for roaming from
each AP or each client

AP Load
39

Q&A
Show us your tweets!
Use today’s webinar hashtag:
#wp_networkforensics
with any questions, comments, or feedback.
Follow us @wildpackets
Follow us on SlideShare!
Check out today’s slides on SlideShare
www.slideshare.net/wildpackets

WildPackets Corporate Overview
Optimizing Network and Application Performance

Corporate Background
• Experts in network monitoring, analysis, and troubleshooting
‒ Founded: 1990 / Headquarters: Walnut Creek, CA
‒ Offices throughout the US, EMEA, and APAC
• Customers spanning leading edge organizations
‒ Mid-market and enterprise lines of business
‒ Financial, manufacturing, ISPs, major federal agencies,
state and local governments, universities
‒ Over 7,000 customers / 60+ countries / 80% of Fortune 1,000
• Award-winning solutions that improve network performance
‒ Internet Telephony, Network Magazine, Network Computing awards
‒ United States Patent 5,787,253 issued July 28, 1998
• “Apparatus and Method of Analyzing Internet Activity”

Why Our Customers Need Us
• VoIP, video, cloud, virtualization, and key business
applications are saturating critical network services
• Evolving network technologies create discontinuities
‒ 1 Gig  10 Gig  40 Gig  100 Gig networks
‒ Wireless, BYOD initiatives
• Users and business can not tolerate network
problems for mission critical services
Increasing demand for better real-time network visibility,
network analytics, network forensics, and DPI

How We Create Value
We provide innovative, industry-leading, real-time
network performance management solutions
‒ Easy-to-use, easy-to-learn user interface
‒ Uniquely extensible solutions
‒ Wireless network leadership
‒ Detailed analytics related to network applications
‒ Fastest network traffic capture appliance in its class
‒ Technical superiority at competitive price point
WildPackets has continually advanced its solution to meet the needs of its
customers

Unprecedented Network Visibility
ROOT-CAUSE ANALYSIS
OmniPeek network analyzer performs deep packet inspection
and can reconstruct all network activity, including e-mail and
IM, as well as analyze VoIP and video traffic quality.
PINPOINT NETWORK ISSUES ANYWHERE
Omnipliance Portable can rapidly identify and troubleshoot
issues before they become major problems—wired or
wireless—down the hall or across the globe.
UNDERSTAND END-USER PERFORMANCE
Omnipliance network analysis and recorder appliances monitor
and analyze performance across critical network
segments, virtual environments, and remote sites.
NETWORK HEALTH
WatchPoint can manage and report on key
device performance and availability across
the entire network, from anywhere on the network.
GLOBAL
DISTRIBUTED
PORTABLE
DPI

A History of Innovation
2003
Distributed real-time
troubleshooting
2001
• First 802.11
wireless analyzer
• First network
analyzer with
automated expert
analysis
2005
Combined
distributed
network and
VoIP
network
analysis
2008
Enterprise-wide
Monitoring and Reporting
2009
Innovative
dashboard
with drill-down for
VoIP
and video
2012
• Capture, record, and
analyze from 40G
network segments
• First wireless network
analyzer to support
801.11ac, k, r, u, v, w
2011
• Total visibility with
zero packet loss
• First wireless
network analyzer to
support capture and
analysis of 802.11n
3-stream wireless
2010
First to achieve 11
Gbps sustained
capture-to-disk
2013
Industry
leading
network
analysis and
recorder
appliances

Product Line Overview

Omni Distributed Analysis Platform
OmniPeek
Enterprise Packet Capture, Decode and Analysis
• Ethernet,1/10 Gigabit, 802.11, and voice and video over IP
• Portable capture and OmniEngine console
• Aggregate analysis data across multiple capture points
Omnipliance
Network Analysis and Recorder Appliances
• High-performance packet capture and real-time analysis
• Stream-to-disk for forensics analysis
• Integrated OmniAdapter network analysis cards up to 40G
WatchPoint
Centralized Enterprise Network Monitoring Appliance
• Aggregation and graphical display of network data
• WildPackets OmniEngines
• NetFlow and sFlow

Omni Distributed Analysis Platform
Software and Turnkey Solutions
• Enterprise monitoring and reporting
‒ WatchPoint Server
‒ OmniFlow, NetFlow, and sFlow Collectors
• Network Analysis and Recorder Appliances
‒ Omnipliance CX, MX, TL
‒ Optional OmniStorage
‒ OmniAdapter analysis cards
• Distributed analysis software
‒ OmniPeek – Enterprise, Professional, Basic, Connect
‒ OmniPeek Remote Assistant
‒ OmniEngine Enterprise
• Portable solutions
‒ OmniPeek network analyzer
‒ Omnipliance Portable

OmniPeek Network Analyzer
• Distributed analysis manager
– Connect to and configure distributed OmniEngines and Omnipliances,
• Comprehensive dashboards present network traffic in real-time
– Vital statistics and graphs display trends on network and application
performance
– Visual peer-map shows conversations and protocols
– Intuitive drill-down for root-cause analysis of performance bottlenecks
• Visual Expert diagnosis speeds problem resolution
– Packet and payload visualizers provide business-centric views
• Automated analytics and problem detection 24/7
– Easily create filters, triggers, scripting, advanced alarms, and alerts

OmniPeek Remote Assistant
Distributed, End-user Packet Capture Made Simple
• Simple to deploy, simple to use
‒ Remote push, download from server, or even
email
‒ Simple user interface - eliminates confusion for
end user
‒ Full fidelity capture - see exactly what the PC
sees
‒ Wired or wireless
• Encrypted file
‒ Only the analyst can open it
‒ Different encryption keys for different locations
or customers
• Detailed client-side/end-user experience
analysis
• Perfect for Tech Support or IT Desktop
support
Trouble call from remote site -
network response is slow.
User downloads and installs
OmniPeek Remote. Encrypted capture
data sent back for analysis.
Network analyst uses OmniPeek
Enterprise to quickly troubleshoot
problem without leaving the office.

OmniWiFi USB WLAN Capture Adapter
• A single device for all WLAN packet capture needs
• Driver included with Omni v7.9 CDs
• Tested and supported with OmniPeek and OmniEngine
• Product features:
• USB device with extension cable
• Dual band operation – 2.4GHz and 5GHz
• Supports all standard international 802.11 channels (a/b/g/n)
• Supports 802.11n - 3 transmit/receive streams (450Mbps)
• Supports 802.11n 20MHz and 40MHz channel operation
• Supports multi-channel aggregation and roaming
• Technical Details:
‒ Size (LWH): 6 inches, 1.5 inches, 5.5 inches
‒ Weight: 5.6 ounces
• Available via Amazon - $99/each
NOTE:
• Capture ONLY – no network services
• Does not capture 802.11ac

New Network Analysis and Recorder Appliances
Powerful Precise
Affordable
The new family of WildPackets Network Analysis and Recorder
appliances gives IT organizations powerful and precise analysis of
high-speed networks in an affordable solution with half the
hardware footprint of rival offerings.

Powerful
‒ Fastest network recorder in its class! Captures traffic up to 20Gbps of real-
world traffic (all size packet distribution)
‒ Scales up to 128 TB of storage
‒ Provides simultaneous real-time analysis and a comprehensive Forensic
Search that rapidly searches through terabytes of captured traffic for the
details relevant to an investigation
Precise
‒ Captures complete network traffic, so you can analyze everything, not just
samples or high-level statistics
‒ Doesn’t drop packets or sacrifice accuracy for speed
‒ Supports rich, detailed analysis, including VoIP and video-over-IP traffic
Affordable
‒ Delivers outstanding price/performance (lower price; half the rack space)
‒ Allows mix of 1G/10G/40G interfaces without buying extra appliances
‒ Solutions start at $16,995
Your network is bigger and faster. Now your analysis solution is, too.

Omnipliance TL
Industry Leading Network Analysis and Recorder Appliance
• Sets a new standard in capture-to-disk speeds
‒ 20Gbps sustained capture to disk rate with zero packet drop
• Best price/performance Network Analysis Appliance
in the market
‒ 20Gbps with only one Omnipliance TL + OmniStorage
‒ Consuming less rack space, less cooling, less electrical power
• Most flexible network interface offering
‒ 1G/10G/40G interfaces supported in a single unit eliminates
additional unit requirement
• Most accurate real-time analytics
‒ Packet-based processing and analysis vs. inaccurate sample-
based calculation

WildPackets Network Analysis Recorder Appliances
Price/Performance Solutions for Every Application
Portable Omnipliance CX Omnipliance MX Omnipliance TL
Ruggedized
Troubleshooting
Less Demanding Networks
Remote Offices
Datacenter Workhorse
Easily Expandable
Enterprise, Highly-
Utilized Networks
Aluminum chassis / 17” LCD 1U rack mountable chassis 3U rack mountable chassis 3U rack mountable chassis
24GB RAM 16GB RAM 32GB RAM 64GB RAM
2 PCI-E Slots 2 PCI-E Slots 4 PCI-E Slots 4 PCI-E Slots
2 Built-in Ethernet Ports 2 Built-in Ethernet Ports 2 Built-in Ethernet Ports 2 Built-in Ethernet Ports
6TB Storage 4/8/16TB Storage 16/32TB Storage 32/48/64TB Storage
Optional OmniStorage:
32/48/64TB
Up to 128TB total Storage
OmniAdapter 1G and 10G OmniAdapter 1G/10G MX OmniAdapter 1G/10G MX OmniAdapter 1G/10G/40G
6.5Gbps CTD 3.8Gbps CTD 8.8Gbps CTD 20Gbps CTD with
OmniStorage

WatchPoint
Centralized Monitoring for Distributed Enterprise Networks
• High-level, aggregated
view of all network
segments
– Monitor per campus, per
region, per country
• Wide range of network
data
– NetFlow, sFlow, OmniFlow
• Web-based, customizable
network dashboards
• Flexible detailed reports
• Direct link to detailed,
packet-based analysis

Comprehensive Support and Services
Standard Support
 Maintenance and upgrades
 Telephone and email contacts
 Knowledgebase
 MyPeek Portal
Premier Support
 24 x 7 x 365
 Dedicated escalation manager
 2 customer contacts per site
 Plug-in reconfiguration assistance
WildPackets Training Academy
 Public, web-based, and on-site classes
 Complete curriculum: technology and product focused
 Practical applications and labs covering network analysis,
wireless, VoIP monitoring and advanced troubleshooting
Consulting and Custom Development Services
 Deployment, configuration, and assessment engagement
 Systems integration and testing
 Application integration, driver, decode, interface development

WildPackets Key Differentiators
• Visual Expert intelligence with intuitive drill-down
– Let computer do the hard work, and return results, real-time
– Packet /payload visualization is faster than packet-per-packet diagnostics
– Experts and analytics can be memorized and automated
• Automated capture analytics
– Filters, triggers, scripting, and advanced alarming system combine to provide
automated network problem detection 24x7
• Multiple issue network forensics
– Can be tracked by one or more people simultaneously
– Real-time or post capture
• User-extensible platform
– Plug-in architecture and SDK
• Aggregated network views and reporting
– NetFlow, sFlow, and OmniFlow

24x7 Network Monitoring,
Analysis, and Troubleshooting

Thank You!
WildPackets, Inc.
1340 Treat Boulevard, Suite 500
Walnut Creek, CA 94597
(925) 937-3200

Wireless Network Analysis 101 VoFi (Voice over Wi-Fi)

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (18)

Similar to Wireless Network Analysis 101 VoFi (Voice over Wi-Fi)

Similar to Wireless Network Analysis 101 VoFi (Voice over Wi-Fi) (20)

More from Savvius, Inc

More from Savvius, Inc (20)

Wireless Network Analysis 101 VoFi (Voice over Wi-Fi)