SDN Journal Authors: John Walsh, Elizabeth White, Liz McMillan, Sven Olav Lund, Simon Hill

Related Topics: SDN Journal, Containers Expo Blog, @CloudExpo

SDN Journal: Blog Post

Requirements for Data Center Networks By @MatMathews | @CloudExpo [#SDN]

It's important when understanding what is needed for a data center network, to think about all six of these functional areas

The Six Requirements for Data Center Networks

One way or another, all data center networks exhibit at least six different functional areas that their operators need to engineer, implement, and operate with a differing set of needs and requirements. Similarly, in one way or another, most of the available SDN and virtualized network solutions available today or in progress aim to deal with issues in one or more of these areas to improve their functional effectiveness, cost, automated-ness, or integrated-ness. Yet some areas receive an inordinate amount of focus/attention and those areas may not necessarily have the most opportunity for improvement. Let’s take a look at these six requirements in order of the opportunity value to bring new levels of effectiveness to data centers.

1. Edge Switching (inter-server or more generically, inter-end point)
Edge switching loosely covers the function of providing switching between end points, whether they be virtual servers, physical servers, storage devices, or terminating services devices (load balancers, firewalls, etc.) It is important to note that in a virtualized server environment, there is typically 2 layers of edge – a set of virtual switches that connect together VMs and a set of physical switches that connect the physical hosts.

Much of the attention and focus in the industry has revolved around edge switching, possibly because this is the area that is most visible to customers in terms of cost. Technologies like distributed virtual switches, network overlays, and trends like white box switching / disaggregated switching software all aim to lower either the capital or operational costs of the edge. Much of this effort is predicated on the decades of near-monopolistic control of major incumbents on the switching infrastructure – yet it is important to note that in the age of merchant silicon (which is not largely offered through a single vendor and is pretty much common to every edge switch on the market), open source (or semi open source) switching operating systems/stacks and virtual switches, much of that control has been mitigated and costs have rightly come down. It will be interesting to see if the industry starts to move its attention to some of the other areas that could offer more potential gain in overall cost savings.

2. Edge Policy
Edge policy refers to the implementation of configuration of those edge switches that allows some type of policy to be enacted on the endpoints that are connecting to the network. The term “policy” here can refer to basic port configuration, all the way up to SLA-level configuration that effects the behavior of the traffic emanating from the connecting end points.

Edge policy has long been a troublesome area for networks (or really any system) because enforcing a policy across a disparate set of systems creates consistency challenges. The key for most policy efforts are a simplified way to express the policy, and a highly efficient way to distribute the policy to many edges. The virtual switching layer (vSwitches) seem like a natural place to solve edge policy due to the ability to quickly iterate the software in the edge devices. The folks at VMWare seem to understand this and are busily working on providing policy enforcement capabilities in their NSX product and tying that to a policy expressing capability in OpenStack (the Congress project). The important point to consider there is if their approach can easily be stretched across both physical and virtual environments for a truly seamless edge policy approach.

3. Fabric Switching (inter-[rack | row | cage | pod | data center]
Fabric switching refers to the switching of traffic for non end-point connected devices or functional blocks. This could be the spine switches connecting multiple ToR leafs together, or could be a core switching layer that connects multiple pods, or even could be a switching capability that connects multiple data centers together. The basic differentiating attribute of core switching versus edge switching is that typically the core does not connect directly to end points, except for ones providing transit services (like firewalls or load balancers).

There has been a surprising lack of attention (and similar lack of concern?) regarding fabric switching in the industry. The default path seems to be higher density spine switches leveraging the commodity silicon cost/performance curves. While “brute forcing” it seems like the path of least resistance here, we can probably look at the history of the “scale up” approach in other IT contexts to notice that it usually works, until it breaks. I’ll have a future post on this in more detail, but suffice it to say that we ought to see more attention paid here to scale-out solutions that attempt to bring to the network the same capabilities that multi-core processors brought to servers/compute.

4. Fabric Policy
Similar to edge policy, fabric policy refers to the implementation of configuration of fabric devices that allows some type of policy to be enacted in the inter-* network. Since most connectivity policy (like access control, port/VLAN configuration) happens on the edge devices, much of fabric policy relates specifically to how the overall network behaves in accordance with specific business imperatives, such as service level agreements or treatment of regulated data in transit.

Fabric policy can be done implicitly (or basically deferred) by treating all paths through the network as equal, and load balancing all traffic equally across all paths (e.g. Equal Cost Multipathing is an example of this implicit or deferred fitting). Or it can be done explicitly with complex mechanisms such as call admission control (CAC) that are typically not found in most data oriented networks. Fabric policy can also be done algorithmically (see “fitting” below), and increasingly as networks become “Software Defined” with a central controller entity and the applications/users of the network require more heterogeneous treatment, this function not only becomes more easily accomplished but also more important, and in conjunction with the concept of fitting, can be a very powerful area to drive effective utilization of network resources.

Surprisingly, there has been almost no talk in the industry about fabric policy, which is very surprising. After all, the guts of the resources that the network has to offer reside in the fabric and controlling those resources via a policy seems to be an area ripe for efficiency and performance improvements. Fabric policy would allow a user to express how inter-rack, inter-pod, or even inter-data center capacity is allocated not in a pre-determined / engineered way, but in a just-in-time or even a predictive way that follows that actual usage patterns of the data center network.

5. Fitting
Fitting is not a term that is generally familiar to folks that think about networking, and may currently be something that is completely unique to Plexxi’s view on the world (although Cisco’s “declarative networking” concept is similar at least in philosophy). Yet fitting it is something that is almost always done even if it is done implicitly. Most networks are built today with a gross level understand of capacity needs, segmentation needs, etc. The network is then engineered to provide, in aggregate, these capabilities via a set of network resources. The concept of fitting is that we explicitly define what each user of the network (a user could be an application, a set of applications, a site, or really any arbitrary grouping) and based on its business-centric attributes, best fit the network resources to that user. The concept of fitting is hard to do manually, or in traditional legacy networks with traffic is looked at on a packet-by-packet or flow-by-flow basis. But in more evolved “software-defined” networks, it becomes much easier to build a higher level view of the users of the network, and allow the software entities (i.e. the controller) to algorithmically determine how best to dole out the resources based on the information it has about the users.

The concept of fitting is extremely power, especially in a software-defined world. As we want and need to be able to leverage networks for a variety of users with a broad spectrum of business criticality, fitting allows us to explicitly put resources where they can have the most benefit rather than the typically networking approach of “spray and pray”, and this presents enormous opportunities not only for cost savings, but for driving business differentiation.

6. Integration and Automation
Finally, all networks need to be integrated to the rest of the world, and increasingly are being automated by the rest of the world. Integration is typically thought of as the way to drive edge policy – e.g. things like leveraging OpenStack Neutron or ML2 plug-ins to automate VLAN provisioning on an edge port. However, integration can not only drive edge policy, but can also drive fabric policy and fitting if done correctly. Ultimately, most companies are moving toward a data center model that is completely “lights out” and the network need not be an exception. Ultimately the data center network provides a services to applications, and as long as those applications can express their needs across the edge and the fabric, a network should be able to provide those services with a minimal amount of hand holding.

A well-integrated network ought to have the ability to express its capabilities across the edge and the fabric in a set of abstract “primitives” that can be easily driven from external systems. The network also should be able to effect different behaviors via policy and have the ability to efficiently fit available network resources to the most critical business needs. And all of this needs to be done in ways that can easily automatable.

It's important when understanding what is needed for a data center network, to think about all six of these functional areas and the potential opportunity to drive cost savings or business differentiation in each of these areas. While much of the industry attention is pointed right now on reducing the costs of the first layer of switching (edge switching), there are many more areas that provide more drastic areas of both cost savings and differentiation opportunity for businesses looking for an IT advantage.

The post The 6 Requirements for Data Center Networks appeared first on Plexxi.

Read the original blog entry...

More Stories By Mat Mathews

Visionary solutions are built by visionary leaders. Plexxi co-founder and Vice President of Product Management Mat Mathews has spent 20 years in the networking industry observing, experimenting and ultimately honing his technology vision. The resulting product — a combination of traditional networking, software-defined networking and photonic switching — represents the best of Mat's career experiences. Prior to Plexxi, Mat held VP of Product Management roles at Arbor Networks and Crossbeam Systems. Mat began his career as a software engineer for Wellfleet Communications, building high speed Frame Relay Switches for the carrier market. Mat holds a Bachelors of Science in Computer Systems Engineering from the University of Massachusetts at Amherst.

@CloudExpo Stories
DX World EXPO, LLC, a Lighthouse Point, Florida-based startup trade show producer and the creator of "DXWorldEXPO® - Digital Transformation Conference & Expo" has announced its executive management team. The team is headed by Levent Selamoglu, who has been named CEO. "Now is the time for a truly global DX event, to bring together the leading minds from the technology world in a conversation about Digital Transformation," he said in making the announcement.
"Space Monkey by Vivent Smart Home is a product that is a distributed cloud-based edge storage network. Vivent Smart Home, our parent company, is a smart home provider that places a lot of hard drives across homes in North America," explained JT Olds, Director of Engineering, and Brandon Crowfeather, Product Manager, at Vivint Smart Home, in this SYS-CON.tv interview at @ThingsExpo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
SYS-CON Events announced today that Conference Guru has been named “Media Sponsor” of the 22nd International Cloud Expo, which will take place on June 5-7, 2018, at the Javits Center in New York, NY. A valuable conference experience generates new contacts, sales leads, potential strategic partners and potential investors; helps gather competitive intelligence and even provides inspiration for new products and services. Conference Guru works with conference organizers to pass great deals to gre...
DevOps is under attack because developers don’t want to mess with infrastructure. They will happily own their code into production, but want to use platforms instead of raw automation. That’s changing the landscape that we understand as DevOps with both architecture concepts (CloudNative) and process redefinition (SRE). Rob Hirschfeld’s recent work in Kubernetes operations has led to the conclusion that containers and related platforms have changed the way we should be thinking about DevOps and...
In his Opening Keynote at 21st Cloud Expo, John Considine, General Manager of IBM Cloud Infrastructure, led attendees through the exciting evolution of the cloud. He looked at this major disruption from the perspective of technology, business models, and what this means for enterprises of all sizes. John Considine is General Manager of Cloud Infrastructure Services at IBM. In that role he is responsible for leading IBM’s public cloud infrastructure including strategy, development, and offering m...
The next XaaS is CICDaaS. Why? Because CICD saves developers a huge amount of time. CD is an especially great option for projects that require multiple and frequent contributions to be integrated. But… securing CICD best practices is an emerging, essential, yet little understood practice for DevOps teams and their Cloud Service Providers. The only way to get CICD to work in a highly secure environment takes collaboration, patience and persistence. Building CICD in the cloud requires rigorous ar...
Companies are harnessing data in ways we once associated with science fiction. Analysts have access to a plethora of visualization and reporting tools, but considering the vast amount of data businesses collect and limitations of CPUs, end users are forced to design their structures and systems with limitations. Until now. As the cloud toolkit to analyze data has evolved, GPUs have stepped in to massively parallel SQL, visualization and machine learning.
"Evatronix provides design services to companies that need to integrate the IoT technology in their products but they don't necessarily have the expertise, knowledge and design team to do so," explained Adam Morawiec, VP of Business Development at Evatronix, in this SYS-CON.tv interview at @ThingsExpo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
To get the most out of their data, successful companies are not focusing on queries and data lakes, they are actively integrating analytics into their operations with a data-first application development approach. Real-time adjustments to improve revenues, reduce costs, or mitigate risk rely on applications that minimize latency on a variety of data sources. In his session at @BigDataExpo, Jack Norris, Senior Vice President, Data and Applications at MapR Technologies, reviewed best practices to ...
"ZeroStack is a startup in Silicon Valley. We're solving a very interesting problem around bringing public cloud convenience with private cloud control for enterprises and mid-size companies," explained Kamesh Pemmaraju, VP of Product Management at ZeroStack, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
Large industrial manufacturing organizations are adopting the agile principles of cloud software companies. The industrial manufacturing development process has not scaled over time. Now that design CAD teams are geographically distributed, centralizing their work is key. With large multi-gigabyte projects, outdated tools have stifled industrial team agility, time-to-market milestones, and impacted P&L stakeholders.
Enterprises are adopting Kubernetes to accelerate the development and the delivery of cloud-native applications. However, sharing a Kubernetes cluster between members of the same team can be challenging. And, sharing clusters across multiple teams is even harder. Kubernetes offers several constructs to help implement segmentation and isolation. However, these primitives can be complex to understand and apply. As a result, it’s becoming common for enterprises to end up with several clusters. Thi...
"Infoblox does DNS, DHCP and IP address management for not only enterprise networks but cloud networks as well. Customers are looking for a single platform that can extend not only in their private enterprise environment but private cloud, public cloud, tracking all the IP space and everything that is going on in that environment," explained Steve Salo, Principal Systems Engineer at Infoblox, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Conventio...
In his session at 21st Cloud Expo, James Henry, Co-CEO/CTO of Calgary Scientific Inc., introduced you to the challenges, solutions and benefits of training AI systems to solve visual problems with an emphasis on improving AIs with continuous training in the field. He explored applications in several industries and discussed technologies that allow the deployment of advanced visualization solutions to the cloud.
The question before companies today is not whether to become intelligent, it’s a question of how and how fast. The key is to adopt and deploy an intelligent application strategy while simultaneously preparing to scale that intelligence. In her session at 21st Cloud Expo, Sangeeta Chakraborty, Chief Customer Officer at Ayasdi, provided a tactical framework to become a truly intelligent enterprise, including how to identify the right applications for AI, how to build a Center of Excellence to oper...
"IBM is really all in on blockchain. We take a look at sort of the history of blockchain ledger technologies. It started out with bitcoin, Ethereum, and IBM evaluated these particular blockchain technologies and found they were anonymous and permissionless and that many companies were looking for permissioned blockchain," stated René Bostic, Technical VP of the IBM Cloud Unit in North America, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Conventi...
In his session at 21st Cloud Expo, Carl J. Levine, Senior Technical Evangelist for NS1, will objectively discuss how DNS is used to solve Digital Transformation challenges in large SaaS applications, CDNs, AdTech platforms, and other demanding use cases. Carl J. Levine is the Senior Technical Evangelist for NS1. A veteran of the Internet Infrastructure space, he has over a decade of experience with startups, networking protocols and Internet infrastructure, combined with the unique ability to it...
22nd International Cloud Expo, taking place June 5-7, 2018, at the Javits Center in New York City, NY, and co-located with the 1st DXWorld Expo will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud ...
"Cloud Academy is an enterprise training platform for the cloud, specifically public clouds. We offer guided learning experiences on AWS, Azure, Google Cloud and all the surrounding methodologies and technologies that you need to know and your teams need to know in order to leverage the full benefits of the cloud," explained Alex Brower, VP of Marketing at Cloud Academy, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clar...
Gemini is Yahoo’s native and search advertising platform. To ensure the quality of a complex distributed system that spans multiple products and components and across various desktop websites and mobile app and web experiences – both Yahoo owned and operated and third-party syndication (supply), with complex interaction with more than a billion users and numerous advertisers globally (demand) – it becomes imperative to automate a set of end-to-end tests 24x7 to detect bugs and regression. In th...