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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
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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 • Good voice quality required for success • Can IEEE 802.11 WLANs provide such quality?
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
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
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)?
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
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
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
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?
Support • Supervisor: • Michel Mouton • Additional Support: • Jean-Michel Lauriol • Daniel Le Bars • The WLAN team: Architecture, QoS, Security, Interoperability, OXE/OXO
Vlan Voice: 172.25.114.192 255.255.255.192 Vlan Data: 172.25.114.32 255.255.255.240 NAT : 172.25.114.210-.219 172.25.114.220-.229 Vlan Management: 172.25.115.229 255.255.255.240 OXE-WLAN solution SLK0 855000 172.25.114.210 9D:28 SLK1 855001 172.25.114.211 9E:69 Radius, TFTP 172.25.115.232 172.25.114.33 172.25.115.225 SLK2 855002 172.25.114.212 BE:01 172.25.114.193 SLK3 855003 172.25.114.213 DD:30 OmniSwitch Router ACS 172.25.115.226 Laptop 172.25.114.35 WLAN OmniAccess OXE IP 853000 172.25.114.230 Management: Port 1 172.25.115.229 Vlan 99 Voice: Port 1 172.25.114.197 Vlan 31 Data: Port 1 172.25.114.34 Vlan 30 CS 172.25.114.194 GD 172.25.114.195 IP 853001 172.25.114.231 UA 850000 SVP Server (with GK) 172.25.114.196 UA 850001