Information Technology Reference
In-Depth Information
Figure 1.30
Push-pull streaming.
(a) Pull Method
1. Buffer map
2. Data request
3. Data packet
Sender
Receiver
(b) Push Method
Data packet
Sender
Receiver
Figure 1.31
Differences between push and pull methods.
the video chunks to the receiver once it has received them. A pull mecha-
nism is then used as a packet loss resilience mechanism.
Gridmedia [49,50] tries to reduce the delay incurred during the informa-
tion exchange and proposes a push-pull mechanism. Once a peer finds that
it regularly pulls video chunks from the same peer, it will then try to switch
to the push mode to reduce the delay.
Gridmedia uses a centralized tracker server. The server records the history
data of the connected peers. When a new peer tries to request the initial peer
list, the tracker server tries to respond with a peer list where half of the peers
are closer to the new peer and the remaining peers are randomly selected by
