Time 0 T start-up Packet generation Servers # of packets Playback rate of Receiver All packets are assumed to be of the same size. The continuous playback at the client is also assumed. Each packet is associated with its playback time. In other words, all packets arriving at the client earlier than their playback times are stored at the buffer of the client; at time to playback a packet, the client fetches the packet from the buffer. In short, the data unit is a single packet, and it also has its playback time (the deadline before the packet should be received at the client). Multipath Live Streaming via TCP: Scheme, Performance and Benefits By Don Towsley’s group, ACM Trans. Multimedia Comp., Comm. and Apps. 2009

T T T GOP GOP 1 segments … Stream time T GOP T+T GOP T+2T GOP 0 GOP 2 segments GOP 3 segments T start-up

T GOP Stream time T+2T GOP T start-up Server 2 Server 1 T+T GOP T start-up Scenario I GOP 1GOP 2

T GOP Stream time T start-up Server 2 Server 1 T+T GOP T start-up Scenario II Server 3 Receiver 1 GOP 1 segments GOP 2 segments GOP 1GOP 2

* Any pairs of two edge nodes (src & dest) has packet transmissions (packets/sec) for a random amount of time (e.g., exponential rv). The offered traffic load for each pair can be also drawn from some distribution. In other words, for each random time, the offered traffic load will be changed. In this way, we can mimic the stochastic variations of network traffics (background traffic) in the core networks.  See if the Gaussian approximation makes sense. How To Do Simulations in ns-2 (tentative) ?From INFOCOM’10 by C.