In parallel computing, all-to-all (also known as index operation or total exchange) is a collective operation, where each processor sends an individual message to every other processor. Initially, each processor holds p messages of size m each, and the goal is to exchange the i-th message of processor j with the j-th message of processor i. Depending on the network topology (fully connected, hypercube, ring), different all-to-all algorithms are required.
