Multicore Packet Processing Forum

By Yann Rapaport, 6WIND Customer Support and Service Manager

This is the fifth post of a series about High Availability capabilities for packet processing software. In the first post the HA requirements for high performance packet processing software were presented, Then, the synchronization of Control Plane protocols, packet processing monitoring and graceful restart were discussed in more detail. This fifth post discusses how to enhance system availability by using the redundant interfaces of a HA equipment.

Starting from the architecture described in the first post, The figure below shows that the second Fast Path can be turned to active. If all the ports of the system are visible from the active Control Plane, it extends the system capabilities.

To implement this architecture, the following extensions have to be provided:

• To be visible, all the ports should have a unique identifier,
• Communication is required between Fast Paths to forward an incoming packet on a port located on the remote Fast Path; chassis generally provide such capabilities with backplane switches,
  Control Plane should be able to send and receive packets through the interface of a remote Fast Path,
• The exception mechanism that informs the networking stack of the Slow Path an incoming packet cannot be processed by the Fast Path also has to be extended. Now, the active Fast Path associated with the inactive Control Plane has to send exceptions to the active Control Plane.

Once interface visibility has been provided, protocols using redundant links such as Link Aggregation (LAG) or ECMP (Equal Cost Multi-Path) can be used to enhance system availability.

More information about 6WINDGate architecture can be found here.

6WINDGate High Availability Architecture Overview is available here.

You can check 6WINDGate FAQ here.