Abstract
The article presents an approach to optimize the multicast transport protocols. The main constraint of this procedure is the orthogonality (linear independence) of protocol parameters. Protocol parameters are variables defined for protocol classes, where the possible values of each parameter are protocol mechanisms, which serve the same goal in the multicast transport protocol. A multi-dimensional hyperspace of protocol parameters is stated, as a mathematical model of the optimization process where every transport protocol is represented as an individual point. A multicast transport Simulator for multiCast (SimCast) has been developed to describe the performance of the transport protocols and to simulate the operation of these protocols for reliable multicasting. The simulator supports the protocol analysis in the hyperspace of protocol parameters.
TopDecomposition Of The Multicast Transport Protocols
Multicast transport protocols have many different properties for data delivery. These attributes can be represented by the previously mentioned protocol parameters (Hosszú, 2005). Each protocol parameter specifies different reliability mechanisms for the same delivery attribute. Such a protocol parameter is, for instance, the repair method, which can have the values like “retransmission”, “forward-error correction”, “interleaving”, or different ways of “local receiver-based repairs” (Luby & Vicisano, 2004). Another parameter is the acknowledgement type, which could hold the possible values “tree-based”, “ring-based” or a “simple direct form”.
Key Terms in this Chapter
Multicast Routing Protocol: In order to forward the multicast packets, the routers have to create multicast routing tables using multicast routing protocols.
Hyperspace of Protocol Parameters: This abstract space is composed of the possible values of each property of the multicast transport protocols. The values represent various protocol mechanisms.
Congestion Window Size: This is the maximal allowed amount of unacknowledged data to be sent to the network.
Socket: A socket is an abstraction, designed to provide a standard application programming interface for sending and receiving data across a computer network. Sockets are designed to accommodate virtually any networking protocol.
Pre-Emptive Scheduling: In case of this scheduling method scheduler can take away execution right from an active object at any time.
Unicast Transport Protocol: They handle the ports in each computer, or improve the reliability of the unicast communication. As examples, the U ser D atagram P rotocol ( UDP ) is a simple unicast transport protocol mainly for the port-handling, and the T ransmission C ontrol P rotocol ( TCP ) is intended for the reliable file transfer.
IP-Multicast: Network-level multicast technology, which uses the special class-D IP-address range. It requires multicast routing protocols in the network routers. Its other name: Network-level Multicast (NLM) .
Multicast Transport Protocol: To improve the reliability of the multicast delivery special transport protocols are used in addition to the unreliable U ser D atagram P rotocol ( UDP ).
FIFO: This is the way packets stored in a queue are processed. Each packet in the queue is stored in a queue data structure. The first data to be added to the queue will be the first data to be removed, then processing proceeds sequentially in the same order.