Windows Sockets 2 Interface Elements for Multipoint and Multicast

The mechanisms that have been incorporated into Windows Sockets 2 for utilizing multipoint capabilities can be summarized as follows:

  • Three attribute bits in the WSAPROTOCOL_INFO structure.
  • Four flags defined for the dwFlags parameter of WSASocket.
  • One function, WSAJoinLeaf, for adding leaf nodes into a multipoint session.
  • Two WSAIoctl command codes for controlling multipoint loopback and the scope of multicast transmissions.

The following sections describe these interface elements in more detail: