THE SINK TREE PARADIGM - CONNECTIONLESS TRAFFIC SUPPORT ON ATM LANS

Asynchronous transfer mode (ATM) is a connection-oriented technology i n which all communication is based on virtual connections established prior to the transfer of data. It is expected that the bulk of traffic carried by the ATM network will be data traffic, e.g., local area net work (LAN) internetwork traffic. Hence, a major issue regarding ATM is the support for connectionless (datagram) traffic. A scheme for the e fficient support for connectionless traffic in ATM LAN's based on tree s of virtual connections is proposed, In this scheme, a sink tree is b uilt for every switch in the LAN. Each tree provides an efficient mean s of routing connectionless traffic from any switch in the network to the sink switch (root) of the tree. The sink tree solution may also be used to broadcast connectionless messages in the reverse direction. T he trees can easily be updated to adapt to topological changes or cong estion in the network. A protocol for refreshing the tree structure us ing the ATM switch routing tables is described. An adaptive rate contr ol solution, in conjunction with fast back pressure at the ATM layer, is presented. It is shown that this scheme achieves high utilization o f available bandwidth for connectionless traffic, has low cell loss pr obability, and small overhead.