Netergy - Stanford - VoIP A Show-and-Tell After the First 12 Month Niko Färber, Yi Liang, Mack Hashemi Bernd Girod, Balaji Prabhakar

Nikolaus FärberNetergy – Stanford - VoIP Growth in VoIP Traffic  VoIP is one of the fastest-growing technologies in communications  900%  5000% billion minutes 2.7 billion minutes 310 million minutes Source: IEEE Spectrum, May 2000

Nikolaus FärberNetergy – Stanford - VoIP Scenario  Legacy LANs often do not support priority queuing mechanisms  DiffServ in Internet backbone is still evolving WAN R S... Host  VoIP has to deal with best-effort service of IP LAN IP Phone T2  Use Netergy’s Audacity T2 as platform for VoIP deployment

Nikolaus FärberNetergy – Stanford - VoIP Netergy Networks’ Audacity T2  Highly integrated OEM solution  Single chip, minimal extension components  Two Ethernet ports  Local PC  Network  Audio functionality  G.711, G.72x  Echo cancellation  Comfort noise  VoIP software stacks  H.323  MGCP  SIP Source:

Nikolaus FärberNetergy – Stanford - VoIP Networked Multimedia  Signal Processing  Improve tolerance to delay variations and loss  Adaptive playout  Loss concealment best-effort VoIP Make Application Network friendly Make Network Application friendly  Networking  Control traffic on LAN to reduce delay variations and loss  Reduced TCP window size exploit interactions, strength, weaknesses

Nikolaus FärberNetergy – Stanford - VoIP Agenda 10:30 Welcome 10:45 Niko Färber Reduced TCP Window Size for VoIP in Legacy LAN Environments 11:30 Yi Liang Adaptive Playout Scheduling Using Time-Scale Modification 12:30 Lunch at Faculty Club 13:30 Mack Hashemi Netergy Network’s Perspective, Open Issues, and Future Work 14:30 End