http://www.lightreading.com/carrier-sdn/sdn-architectures/opendaylight-unveils-open-source-sdn-controller/d/d-id/707559?f_src=lightreading_lightreading_weekly_newsandviews&cid=NL_LRWeekly_20140206

Hydrogen's architecture was announced last fall. Today's release is functional code that acts as a service abstraction layer that can provide the northbound capabilities to a wide range of routers and switches, and comes in a basic edition and two more advanced editions, one targeting the datacenter and another specifically adapted for service providers. The basic edition of the platform incorporates an OpenFlow Plugin and an OpenFlow Protocol Library, as well as Open vSwitch Database (OVSDB) support and YANG tools that enable NETCONF for automatic network configuration.

The service provider edition adds support for protocols such as BGP-LS, LISP, and SNMP, all used in service provider networks, along with APIs for controlling Ethernet switches and Defense4All, a distributed denial of service attack detection and mitigation framework

​.​