Number of access channels on the switch

A limitation of EtherChannel is that all the physical ports in the aggregation group must reside on the same switch except in the case of a, where they can reside on different switches on the stack. protocol removes this limitation by allowing the physical ports to be split between two switches in a triangle configuration or 4 or more switches in a mesh configuration. Cisco's (VSS) allows the creation of a Multichassis Etherchannel (MEC) similar to the protocol. [pdf]