Extending Virtual Networks with SDN

SDN can take you to a place where the existing network is not there, but you may want to reconsider forwarding the post.

SDN is considered as the main way for enterprises to realize full virtualization network, and even the main way to realize full virtual data center.

One of the main benefits of all of these virtualization is scale. Without hardware limitations, the SDN environment will be able to change depending on the user's changes, which brings the era of data connectivity anywhere.

However, if so, why are there so many scalability restrictions around the virtual network platform?

Transfer restrictions

It turns out that while the separation of control plane and forwarding plane can bring a lot of benefits, the virtual network is still limited by the ability to transfer, and the virtual networks need to be published to record the MAC address and other network data needed to drive the packet to its final destination. In fact, this challenge continues to grow as commands and requests from the physical layer infrastructure and the fast-changing virtual infrastructure are flooded with publications. So far, we have developed technologies to address this problem, such as shortest path bridging and IP packet drowning, but the question is whether the current virtual network platform can provide scalability for the enterprise.

Obviously, the first solution we can think of is to improve the flow table itself. This is the approach Corsa technology has taken in its new OpenFlow hardware data plane (DP6420 and DP6440), which are designed to be used in both data center and carrier environments. The device provides local OpenFlow 1.3 support and is capable of handling multiple traffic tables and millions of traffic, enabling rapid creation of flow tables and tens of thousands of traffic modification per second. They also support a variety of network port configurations, including 48x10gbe, 4x40gbe, and 4x100gbe.

What if the tens of thousands of flow command turns into tens of millions of (the enterprise is likely to deploy a very large architecture)? How can you accommodate (at reasonable cost) a large number of TCP connections and UDP traffic? In fact, these problems are beyond your reach, and you should use the destination based forwarding method currently deployed on most 2-tier and 3-tier network switches. With an intelligent architecture, SDN devices can be configured correctly through automatic querying and API programming. The rate of change in the publication itself is negligible. In fact, you'll see smaller forwarding than now, because the controller will continue to remove the dead link instead of overwriting the MAC address to each virtual switch.

Virtual network Visibility

However, extending the network outward will not only affect the issue of forwarding, but also visibility. Tilera and Procera Network have teamed up with new SOC solutions to extend the DPI in an outward-extending virtual network that combines the TLENCORE-GX adapter and the Procera network to apply a visual library. The goal here is to provide wire-speed application intelligence directly on the server's 4 to 7-tier network to achieve depth threat monitoring, QoS management, and other capabilities. The system also provides up to 225,000 unique URLs per second and 7-tier network traffic classification, which can be used to forward specific traffic to optimize the host.

No matter how you extend a virtual network, there are two facts that are undeniable: one is that even the most efficient resource utilization does not ensure that the software definition architecture can be extended indefinitely. At some point, the hardware will play some role, although through the appropriate design, this hardware impact can be controlled in the minimum range.

The second is that all network structures must find a way to discover and map other resources, even those outside the enterprise's direct control. And as SDN becomes more pervasive, the need to automate these processes will increase.

In essence, virtual networks are designed to be extensible, which certainly goes well beyond the physical network. But that doesn't mean you can get unlimited resources.