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Highlight 1: AER/NCA

Highlight 1: AER/NCA. Active Packet. Traditional Error Recovery (TCP). Active Error Recovery (AER). Sender. Conventional Routers. Retransmitted message. Active Routers. Active Node. Link causing loss of original message. Active Packet ‘. Lost message retransmission request.

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Highlight 1: AER/NCA

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  1. Highlight 1: AER/NCA

  2. Active Packet Traditional Error Recovery (TCP) Active Error Recovery (AER) Sender Conventional Routers Retransmitted message Active Routers Active Node Link causing loss of original message Active Packet ‘ Lost message retransmission request Loss detected by nearest router downstream from loss Message retransmitted by nearest router upstream from loss Receiver Repair latency is a complete round trip time Repair latency much less than one round trip Active Multicast Repair Services • Base premise: • Active Networking can significantly improve latency, efficiency, and scalability of transport protocols

  3. Sender Repair Servers Routers Receivers AER/NCA AER Repair Servers (RSs) • Co-located with routers AER loss handling: • rcvrs and RSs unicast NAKs • RSs subcast NAKs one level downstream • subcast repairs, NAK supression NCA • Estimating worst receiver • TCP friendliness • Decoupled from AER

  4. AER/NCA Send Applications (Sun Ultra 5s/Solaris) NIST Net WAN Emulators (200 MHz Pentium Pros/LINUX) CANEs Active Node (Dual Processor Sun Ultra 2/Solaris) NIST Net WAN Emulator (733 MHz Pentium III/LINUX) CANEs Active Node (Dual Processor Sun Ultra 2/Solaris) AER/NCA Receive Apps (Windows NT with HW MPEG2 Decoders) Team 4 Demonstration Configuration

  5. AER Demo: Enhanced Reliable Transport Unicast MPEG-2 Video Client Unicast MPEG-2 Video Client Video Server (Unicast) Emulated bottleneck link With repair servers inactive, dropped packets repaired by video server - increased latency delays playout With repair servers active, dropped packets repaired locally - decreased latency speeds playout

  6. Demo Performance Indicators Total AER Packets Received Short-term average “goodput” in packets/sec Short-term average of error recovery ratio -> dropped packets recovered / dropped packets detected Short-term average delay in packet recovery

  7. AER Demo: Semi-reliable Multicast Multicast MPEG-2 Video Client Multicast MPEG-2 Video Client Video Server (Multicast) Emulated bottleneck link With repair servers inactive, dropped packets not repaired before playout time: quality suffers With repair servers active, dropped packet repaired before playout time: quality improved

  8. AER Demo: Bandwidth Sharing Multicast Data Clients Multicast Data Clients Data Server (Multicast) Emulated bottleneck link Independent sessions share bandwidth fairly as number of sessions is increased

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