performance characterization of voice over wireless lans
DESCRIPTION
Performance Characterization of Voice over Wireless LANs. Lionel PEREZ June 2nd, 2005. Agenda. Abstract Specific Tasks Available Material Achieved Tasks References Support Related Work. Abstract. VoIP over WLANs, the « killer application » Inexpensive and convenient mobile telephony - PowerPoint PPT PresentationTRANSCRIPT
Performance Characterization of Voice over Wireless
LANsLionel PEREZ
June 2nd, 2005
Master Thesis Project - Lionel Perez – June 2005 — 2
Agenda
> Abstract
> Specific Tasks
> Available Material
> Achieved Tasks
> References
> Support
> Related Work
Master Thesis Project - Lionel Perez – June 2005 — 3
Abstract
> VoIP over WLANs, the « killer application »
> Inexpensive and convenient mobile telephony
> Good voice quality required for success
> Can IEEE 802.11 WLANs provide such quality?
Master Thesis Project - Lionel Perez – June 2005 — 4
More parameters than wired LAN !
> Loss, Delay, Jitter
> Impact of rate adaptation, power management on loss, delay, jitter
> Impact of encrypction on loss, delay, jitter
> Impact of RTS/CTS on loss, delay, jitter
> Association performance, Authentication performance,
> Roaming time, Rate adaptation time,
> QoS (EDCF, WMM, WMM-SA)
> Packet size
Master Thesis Project - Lionel Perez – June 2005 — 5
Abstract
> Purposes of the project:
• Characterize the performance of a telephony solution based on Voice over IP over Wireless LANs (VoWLAN)
• Conduct measurements and simulation to identify the most significant parameters impacting voice quality
• Market and Strategy requirements:– Avoid time and cost-intensive tests– Independence from OEMs
Master Thesis Project - Lionel Perez – June 2005 — 6
Proposed Tasks 1/2
> Learn about the relationship between traffic parameters (delay, jitter, packet losses) and voice quality (MOS ,E-model: R-Value)
> Explore different scenarios that directly impact these parameters:• the QoS mechanisms implemented (802.11e)?• the security features (802.11i)?• 802.11a,b or g ?• the codec (opt)?• the signalling protocol (opt)?
Master Thesis Project - Lionel Perez – June 2005 — 7
Proposed Tasks 2/2
> Perform measurements of these parameters under the different possible considerations
> Use the ns2 network simulator or other (OMNET++?) to model and simulate some of these configurations
>Define key tests to be conducted in order to ensure a given performance
Master Thesis Project - Lionel Perez – June 2005 — 8
Available Material
> The « alpha test »: the VoWLAN solution deployed in our premises
> The «platform» (testing lab)
> PCs and laptops equiped with NICs
> Wireless Switches, Access Points, Wifi phones
> Professional measurement tools:• 2 Veriwave Tests Units• Wildpacket’s Airopeek• Airmagnet Laptop• Ixia Ixchariot
Master Thesis Project - Lionel Perez – June 2005 — 9
Achieved Tasks
> Bibliographical Research Complete
> Read the key articles
> Understand the available tools
> Discover ns2
> During the internship:• Discover Alcatel’s VoWLAN Solution• Evaluate Sigmum Wiplan (Planning Software)• Conduct Site Surveys• Basic mock-up configuration• The VoWLAN toolkit
Master Thesis Project - Lionel Perez – June 2005 — 10
Related Work
> “Can I add a VoIP call?”, S. Garg and M. Kappes
> Voice over IEEE 802.11b Capacity, Coupechoux, Kumar, Brignol (Alcatel), 2004
> Simulation of 802.11e
> Basic security features (WEP)
> New QoS mechanisms?
> New Security mechnisms?
> New Power Management mechanisms?
Master Thesis Project - Lionel Perez – June 2005 — 11
Support
> Supervisor:• Michel Mouton
> Additional Support:• Jean-Michel Lauriol• Daniel Le Bars• The WLAN team: Architecture, QoS, Security,
Interoperability, OXE/OXO
Master Thesis Project - Lionel Perez – June 2005 — 12
Thank you.
Master Thesis Project - Lionel Perez – June 2005 — 13
OXE-WLAN solution
UA 850000
ACS 172.25.115.226
WLAN OmniAccess
SLK0 855000172.25.114.2109D:28
OmniSwitch Router
SVP Server (with GK)172.25.114.196
Management: Port 1 172.25.115.229Vlan 99Voice:Port 1 172.25.114.197Vlan 31Data:Port 1 172.25.114.34Vlan 30
CS 172.25.114.194GD 172.25.114.195
UA 850001
172.25.114.193
NAT : 172.25.114.210-.219
172.25.114.220-.229
SLK1 855001172.25.114.2119E:69
SLK2 855002172.25.114.212BE:01
IP 853000172.25.114.230
IP 853001172.25.114.231
SLK3 855003172.25.114.213DD:30
172.25.114.33
Vlan Voice:172.25.114.192255.255.255.192
Vlan Data:172.25.114.32255.255.255.240
Vlan Management:172.25.115.229255.255.255.240
172.25.115.225
Laptop172.25.114.35
Radius, TFTP172.25.115.232
OXE