Jayshree Ullal
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Jayshree Ullal
The Ideal Cloud Network: SDN Overlays, Underlays or Both?
Enterprises are still a complex mix of legacy and newer cloud applications, yet smart use of universal SDN-based cloud networks is the great equalizer in bringing enterprises and the new applications of the cloud together. Evolutionary migration strategies from a mainframe to a client-server architecture can also be applied to the next phase of cloud and virtual age networking. To appreciate how they apply, one must better understand the diverse definitions of SDN, and its true applicability in next generation networks. Let’s review some of the terminology often used and confused in our industry.
Overlay SDN: The most visibly promoted controller for SDN overlays today is VMware’s NSX (Microsoft System Center, Juniper Contrail and Nuage Networks may also fall into this category). Some networking features and functions are moved into overlays to control the data, flow or forwarding path. This includes:
1. Software overlays to shift management functions from the control plane of the network to servers
2. Specific use-cases such as server virtualization, L4-L7 load balancing, security, Openflow etc.
Functional controllers leverage existing physical networks and apply features and functions such as provisioning that can be used via abstraction, APIs, a CLI and limited scripting.
Underlay SDN: Controllers do Continue reading
Separating Hype from Reality in SDN
Lately, two acronyms have been making the rounds: SDN (Software Defined Networking) and ACI (Application Centric Infrastructure – promoted by Cisco). Both have things in common which equate to great marketing: a delightful vision and being difficult to pin down in terms of a crisp definition. Let me try to clarify as best I can with the disclaimer that this is purely my perspective representing Arista, as we celebrate the deployment of our second million ports of cloud networking.
The common view is that SDN is a controller or a set of network management products based on Virtualization Technologies or OpenFlow. At Arista we have a more pragmatic view. To us, SDN is a programmatic suite of open interfaces that allows applications to drive networking actions. Unlike the misconception that SDN is just a controller, I believe SDN is about scaling the control, management and data plane with programmatic and open interfaces. This means customizing the network with high-level scripting and programmatic languages, structured and machine-readable APIs, and standards-based protocols as well as interoperability with controller-friendly networks.
As we enter 2014, we are witnessing the deployment of SDN via Arista EOS and associated programmable network applications such as Advanced Telemetry, Continue reading