ExtremeXOS OpenFlow

To implement OpenFlow, Extreme Networks has ported the Open Virtual Switch open source OpenFlow implementation to ExtremeXOS to create an OpenFlow 3.1-compliant solution.

Feature highlights include:

• Ability to Dynamically Add OpenFlow—ExtremeXOS is designed as an extensible operating system with an important resiliency capability that enables dynamic loading of new features without having to reboot or disrupt network operation, helping maintain system uptime.
• Hybrid Mode Support for Both OpenFlow and Classic Ethernet Networks—ExtremeXOS supports OpenFlow hybrid switch functionality. The default behavior for packets arriving on a switch port is to process the packet using standard Ethernet switching techniques (FDB learning and forwarding, ACL and QoS processing, VLAN isolation, and L3 routing). ExtremeXOS CLI commands are used to enable OpenFlow and to assign physical ports and LAGs belonging to specific VLANs to the OpenFlow domain for external control by an SDN controller. Extreme Networks switches support hybrid mode on a per VLAN basis. A single port can support both OpenFlow-controlled VLANs and VLANs with traditional networking services.
• LAG for Resiliency and Redundancy ExtremeXOS—OpenFlow supports LAGs for system redundancy and bandwidth scaling. ExtremeXOS represents an entire LAG as a single high capacity link to an SDN controller, enabling existing SDN applications to use the bandwidth scaling, load balancing, and resiliency characteristics of a LAG without being required to manage the individual member of the LAG directly. A LAG is used to incrementally increase bandwidth between switches as needed. For example, as a 1 GE port becomes oversubscribed, a second 1 GE port can be added into the LAG to increase the bandwidth between switches, without having to make the jump directly from 1 GE to 10 GE.
• Hardware Queuing—Extreme Networks' OpenFlow feature includes a rich set of OpenFlow-controlled QoS/slicing capabilities based on an extensive set of existing QoS capabilities. ExtremeXOS enables the definition of QoS profiles for OpenFlow packet egress queuing control. ExtremeXOS QoS profiles support rate limiting and rate shaping with single and dual rate QoS policies in addition to configurable drop policies. Using the ExtremeXOS CLI, interface queues are configured based on operator-defined service policies, and then assigned to physical ports. When those same physical ports are also configured as OpenFlow ports, the Extreme Networks switches report configured profile queues to the SDN controller with the Queue_Get_Config_Reply message. This enables the SDN controller to dynamically program the flows that are mapped to those configured queues, providing a rich set of traffic-differentiated services.
• Automated Flow Management for Increased Flow Table Size—ExtremeXOS OpenFlow fully supports platform-based hardware capabilities. ExtremeXOS intelligently classifies and maps controller flow-mods to the appropriate platform hardware resources to ensure maximum flow scaling. Complex flows requiring combinations of L2 and L3 match conditions are instantiated in platform TCAM ACL hardware. Simple L2-only flows are mapped to the more scalable platform L2 forwarding table. ExtremeXOS OpenFlow also fully supports OpenFlow idle_timeout and hard_timeout flow mods to evict flows from the hardware resources efficiently and effectively, allowing new flow entries as required.