TRILL (Transparent Interconnection of Lots of Links)
TRILL is an effort to overcome some of the limitations of Ethernet switching. The approach is to use the power of link-state routing protocols such as typically used in Layer-3 (e.g. IP) networks. In order to retain (or emulate) the simple and wildly popular model of Ethernet connectivity, TRILL uses encapsulation internally. The TRILL encapsulation includes a TTL (time-to-live) field, so that temporary loops don't lead to catastrophic accumulation of traffic as easily.
The protocols are standardized by the TRILL Working Group
in the IETF
. This standardization activity grew out of Radia Perlman's work on "RBridges" or routing bridges.