Reliable Multicast

Tree based multicast protocols often use hierarchical loss recovery where some special routers called proxy are assigned for retransmission handling. This leads to traffic redundancy and latency. The existing approaches of loss collected retransmission based on X-OR selective principle, which minimizes the number of packets to be retransmitted. However, the receivers send NACKs to the source expecting the retransmission from the source. This overwhelms the source affecting the throughput and processing time. In this paper we analyze the processing time of sender in loss collected retransmission by placing proxies at the intermediate router. The simulation results reveal that our framework minimizes the processing time of sender than simple loss collected retransmission model.

Summary The capacity gain of active networks has been extensively studied in the reliability of multicast. It has been shown that active networks improve the network reliability by reducing the number of packet retransmission between the source and receivers in lossy networks. However, the existing active reliable multicast protocols are based on the receiver-initiated class that attributes the responsibility of

The Pragmatic General multicast (PGM) and Elastic Reliable Multicast (ERM) are reliable multicast protocols. The difference between reliable and unreliable multicast protocol is that they make sure that the multicast data packets gets to its destinations. Both the PGM and ERM sends flood messages to the Rendezvous Point source (RPS) from the source node towards the stub nodes which then forward it to leaf nodes, leaf nodes that are not interested sends a prune message while any leaf node that misses a packet sends a message to the RPS through the stub node requesting for the multicast packet. A repair multicast packet is then forwarded to all leaf nodes that requested for it. In the reliable hybrid multicast protocol (RHMP) being proposed the stub nodes originates the flood message to the leaf and uninterested leaf sends prune message, any stub that has one or more interested leaf sends a join message to the RPS. If a leaf node in the multicast distribution misses a multicast packet it requests a repair packet from its stub node and the stub node sends the repair data. A simulation model was developed to mimic the behaviour of PGM, ERM and RHMP in different network size using hierarchical network and the control bandwidth overhead (CBO) for each of the multicast protocols was calculated, the CBO was use as the cost metric. The result shows that the RHMP uses less CBO than PGM and ERM in a sparsely and densely populated network. For state storage it was discovered that the RHMP uses more resources at the stub nodes than at the source / RPS or leaf node when compared with PGM and ERM, but since the stub nodes are present in a distributed way it does not necessarily affect the multicast process.

Abstract-This paper presents a novel loss recovery scheme, Active Re-liable Multicast (ARM), for large-scale reliable multicast. ARM is “active” in that routers in the multiciist tree play an active role in loss recovery. Ad-ditionally, ARM utilizes soft-state storage within the ...

The impetus for our work is the scalability, availability, and manageability challenges in commercialdeployments of open systems. The speci#c application we target is the operational information system usedby Delta Airlines. Systems like these must facilitate new application development, as well as enable Delta'slegacy infrastructuretoparticipate in the emerging electronic commerce world. In this paper, we de#nethe problems faced by such Operational

Reliable multicasting takes help of re-transmissions from the source, to recover lost packets .This imposes a huge overhead on the bandwidth-constrained ad hoc network. In On Demand Multicast Routing Protocol (ODMRP), the multicast members send Join Replies to the ...

In this paper, we study reliable multicast at the MAC layer for IEEE 802.11 Wireless LANs. In IEEE 802.11, multicast transmissions are unreliable in the sense that multicast frames are transmitted from the access point (AP) without an ACK being returned from each receiver as in unicast transmissions. As a result, transmitted multicast frames may be lost due to collisions or errors. There are two types of reliable multicast at the MAC layer proposed for 802.11 in the literature: one is ACK-based and the other is a leader-based mechanism. For the ACK-based mechanism, the AP monitors the frame reception progress of all receivers and retransmits frames whenever no ACK is received from any receiver; for leader-based mechanism, the AP retransmits frames only when no ACK frame is received from the selected leader. We analyze their performance in terms of frame holding time at the AP, and conduct simulation to validate our analytical model. We also propose a new channel acquisition and multicast notification mechanism called RTS/CTS/SEQ to improve the performance of existing work for reliable multicast in IEEE 802.11 WLANs.

AB STRAC T As the field of embedded networked sensing matures, useful abstractions are emerging to satisfy the needs of increasingly complex applications. This paper demonstrates Statesync, an abstraction for reliable dissemination of application state through a multi-...

This paper contains a detailed description of the congestion control algorithm of TRAM, a tree-based reliable multicast protocol. This algorithm takes advantage of regular acknowledgements from the receivers that propagate back to the sender via the repair tree. This scalable feedback mechanism is used to collect receiver credits. Complementing the windowing mechanism, packet transmission is smoothed by using a data rate commensurate with the window size.