Hi,
The Modular Layer 2 (ml2) plugin is a framework allowing OpenStack Networking to simultaneously utilize layer 2 networking technologies. It currently works with the existing openvswitch, linuxbridge, and hyperv L2 agents, and is intended to replace and deprecate the monolithic plugins associated with those L2 agents. The ml2 framework is also intended to greatly simplify adding support for new L2 networking technologies, requiring much less initial and ongoing effort than would be required to add a new monolithic core plugin. A modular agent may be developed as a follow-on effort.
Hope thats helps,