Distributed Split Multi-Link Trunking (DSMLT) or Distributed SMLT is a computer networking technology developed at Nortel to enhance the Split Multi-Link Trunking (SMLT) protocol. DSMLT allows the ports in a trunk to span multiple units of a stack of switches or to span multiple cards in a chassis, preventing network outages when one switch in a stack fails or one card in a chassis fails. US 6496502, Fite, Jr., David B.; Nicholas Ilyadis & Ronald M. Salett, "Distributed Multi-Link Trunking Method and Apparatus", issued 2002-12-17
Fault-tolerance is a very important aspect of Distributed Split Multi-Link Trunking (DSMLT) technology. Should any one switch, port, or more than one link fail, the DSMLT technology will automatically redistribute traffic across the remaining links. Automatic redistribution is accomplished in less than half a second (typically less than 100 milliseconds) so no outage is noticed by end users. This high speed recovery is required by many critical networks where outages can cause loss of life or very large monetary losses in critical networks. Combining Multi-Link Trunking (MLT), DMLT, SMLT, DSMLT and R-SMLT technologies create networks that support the most critical networks.