Broadcasting (networking)

In computer networking, telecommunication and information theory, broadcasting is a method of transferring a message to all recipients simultaneously. Broadcasting can be performed as a high-level operation in a program, for example, broadcasting in Message Passing Interface, or it may be a low-level networking operation, for example broadcasting on Ethernet. All-to-all communication is a computer communication method in which each sender transmits messages to all receivers within a group. In networking this can be accomplished using broadcast or multicast. This is in contrast with the point-to-point method in which each sender communicates with one receiver. There are four principal addressing methods in the Internet Protocol: In computer networking, broadcasting refers to transmitting a packet that will be received by every device on the network. In practice, the scope of the broadcast is limited to a broadcast domain. Broadcasting is the most general communication method and is also the most intensive, in the sense that many messages may be required and many network devices are involved. This is in contrast to unicast addressing in which a host sends datagrams to another single host, identified by a unique address. Broadcasting may be performed as all scatter in which each sender performs its own scatter in which the messages are distinct for each receiver, or all broadcast in which they are the same. The MPI message passing method which is the de facto standard on large computer clusters includes the MPI_Alltoall method. Not all network technologies support broadcast addressing; for example, neither X.25 nor Frame Relay have broadcast capability. The Internet Protocol Version 4 (IPv4), which is the primary networking protocol in use today on the Internet and all networks connected to it, supports broadcast, but the broadcast domain is the broadcasting host's subnet, which is typically small; there is no way to do an Internet-wide broadcast.