Efficient Any Source Overlay Multicast In CRTBased P2P Networks  A CapacityConstrained Approach In this work, we have considered designing a highly efficient capacityconstrained overlay multicast protocol; it is designed specifically for an existing Chinese Remainder Theorem (CRT)  based structured P2P architecture 9. Such an architecture has been the choice for its structural advantages over DHTbased architectures. It is worth mentioning its most important advantage from the viewpoint of speed of communication, that is its diameter, which is only 3 overlay hops. The protocol is not restricted to a single data source and it incorporates peer heterogeneity as well. We have also designed another any source capacityconstrained multicast protocol that incorporates the unique idea of transforming the multicast problem to a broadcast one 10. We have compared analytically the performance of the two protocols; it has led to the observation that use of this unique idea 10 cannot take advantage of all structural advantages of a CRTbased system resulting in decrease in performance. However, the proposed multicast source discovery protocol has used this unique idea offering good performance.

Improving P2P LiveContent Delivery using SVC P2P content delivery techniques for video transmission have become of high interest in the last years. With the involvement of client into the delivery process, P2P approaches can significantly reduce the load and cost on servers, especially for popular services. However, previous studies have already pointed out the unreliability of P2Pbased live streaming approaches due to peer chum, where peers may ungracefully leave the P2P infrastructure, typically an overlay networks. Peers ungracefully leaving the system cause connection losses in the overlay, which require repair operations. During such repair operations, which typically take a few roundtrip times, no data is received from the lost connection. While taking low delay for fastchannel tunein into account as a key feature for broadcastlike streaming applications, the P2P live streaming approach can only rely on a certain media prebuffer during such repair operations. In this paper, multitree based Application Layer Multicast as a P2P overlay technique for live streaming is considered. The use of Flow Forwarding (FF), a.k.a. Retransmission, or Forward Error Correction (FEC) in combination with Scalable video Coding (SVC) for concealment during overlay repair operations is shown. Furthermore the benefits of using SVC over the use of AVC single layer transmission are presented.