Dell-Proprietary Aggregation

Dell PowerConnect switches use IEEE 802.1AX-2008 for Link Aggregation.

Standardization process

By the mid 1990s, most network switch manufacturers had included aggregation capability as a proprietary extension to increase bandwidth between their switches. But each manufacturer developed its own method, which led to compatibility problems. The IEEE 802.3 group took up a study group to create an inter-operable link layer standard in a November 1997 meeting.[2] The group quickly agreed to include an automatic configuration feature which would add in redundancy as well. This became known as "Link Aggregation Control Protocol".

Initial release 802.3ad in 2000

As of 2000[update] most gigabit channel-bonding schemes use the IEEE standard of Link Aggregation which was formerly clause 43 of the IEEE 802.3 standard added in March 2000 by the IEEE 802.3ad task force.[3] Nearly every network equipment manufacturer quickly adopted this joint standard over their proprietary standards.

Move to 802.1 layer in 2008

David Law noted in 2006 that certain 802.1 layers (such as 802.1X security) were positioned in the protocol stack above Link Aggregation which was defined as an 802.3 sublayer.[4] This discrepancy was resolved with formal transfer of the protocol to the 802.1 group with the publication of IEEE 802.1AX-2008 on 3 November 2008.

Pulled from this article:

http://en.wikipedia.org/wiki/Link_aggregation

Hope this helps with your question.