Advanced Computing in the Age of AI | Monday, October 3, 2022

Cumulus, Midokura Team Up On Open Networks 

There is more than one way to skin the software-defined network cat, and Midokura and Cumulus Networks are teaming up to provide an alternative to various OpenFlow implementations as well as VMware's NSX overlay method.

Cumulus Networks, as EnterpriseTech has previously reported, is on the point of an open networking movement that is being encouraged by Facebook and other members of the Open Compute Project to encourage switch makers to create more industry standard switch platforms and to allow companies to install various network operating systems on them. Cumulus has donated its Open Network Install Environment to the OCP to plunk a network operating system on a whitebox switch, and is obviously hoping that its own Cumulus Linux switch operating system will be the one of choice. Through November 2013, the last time that the company gave out numbers, it had over 10,000 switches, mostly in hyperscale datacenters, running Cumulus Linux.

Midokura is one of several SDN software providers, and unlike many companies in this space, it is not married to the OpenFlow protocol and therefore switch hardware that must be tweaked so it can support OpenFlow. With OpenFlow, the control plane and the data plane are separated from each other in the switch, and a central OpenFlow controller actually manages all of the forwarding tables externally for that control plane. With this level of virtualization in the switch, forwarding tables can be updated instantly as traffic patterns moving north-south from servers (and possibly storage) out to users and east-west between servers and or storage change.

Midokura is not the only one who is not focusing solely on OpenFlow. Juniper Networks is peddling an SDN stack called Contrail that similarly relies on other network protocols to accomplish the same task, and switching juggernaut Cisco Systems is baking its SDN software, called the Application Policy Infrastructure Controller, into its switch chips and a streamlined version of its NX-OS network operating system.


The way the MidoNet overlay works, explains Dan Conde, product manager at Midokura, the network overlay is not relying on any particular hardware and it supports both VMware's VXLAN and Microsoft's NVGRE Layer 2 overlays for Layer 3 networks to extend a virtualize networks across clusters and datacenters. This overlay is what allows for virtual machines to move between multiple clusters and datacenters without losing their connection to the network. In the past, when you did a live migration outside of the virtual switch inside of a single server host, network settings would be lost and had to be reset by hand by network administrators. In effect, MidoNet is akin to a network hypervisor, providing virtual networks and routers that in actuality run on physical switches and routers.

The partnership between Cumulus Networks and Midokura does several things. First, the MidoNet SDN software is based on the Open vSwitch open virtual switch created by Nicira (now owned by VMware) that is becoming something of a standard for open switching. Midokura is adapting MidoNet so it can talk through the Open vSwitch Data Base agent in Cumulus Linux to manage and provision any physical switch that runs this network operating system.

Looking farther out into the future, Midokura is thinking about how it might run various network functions in virtual machine slices atop Cumulus Linux, right on the switching hardware itself. These days, an open switch design as well as some closed ones include X86 engines for precisely this purpose.

One key thing Conde wanted to stress is that on switches that use Broadcom's Trident-II switch ASICs, which support VXLAN overlays in their circuits, can push data at line speed between the virtual switches and physical switches.


Midokura and Cumulus Networks say they will have an integrated stack in technology preview by May and a combined solution ready for market by the third quarter.

While the software tools that Cumulus Networks and Midokura have created are referred to as open networking and are based on many pieces of open source software (such as Linux and Open vSwitch), the funny bit is that neither Cumulus Linux nor MidoNet are themselves open source products.

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