Welcome!

@ThingsExpo Authors: Elizabeth White, Liz McMillan, Pat Romanski, Bob Gourley, Sematext Blog

Related Topics: @ThingsExpo, Java IoT, @CloudExpo, @BigDataExpo, SDN Journal, OpenStack Journal

@ThingsExpo: Blog Feed Post

PubSub and Other Disruptive Emerging Network Models

What's new with software-defined architectures is not just the logical separation but the physical decoupling

When people write about software-defined architectures being "disruptive" to the network they're doing a bit of a disservice to just how much change is occurring under the hood in the engine that drives today's businesses. The notion of separating control and data planes is superficial in that it describes a general concept and it isn't really all that radical a change, if you think about it.

The control and data planes have always been separate. We have, since the need for web-scale networks came about, implemented separate topological (and usually physical) networks specifically for the purpose of segregating control traffic from the data path. The reasons for this are many: to keep management (control) traffic from interfering with the delivery of applications (and vice versa), to enable a model in which control over the critical path for applications could be secured and to ensure access to necessary control functions in the face of failure or attack.

What's new with software-defined architectures is not just the logical separation but the physical decoupling and change in component responsibility. In traditional networks there is a logically separate control plane, but it is distributed; it resides on each physical component. In software-defined networks it is physically separate but it is centralized; control responsibility resides in a single component, the "controller".

Now, OpenStack and emerging models for scaling systems that will be responsible for managing communication with and for the Internet of Things (like MQTT) use a similar control model, but it's not as active as a software-defined architectural model, it's more a passive model. That's the nature of PubSub imposing itself on the network.

PubSub Control Modelpubsub-model

PubSub (publish / subscribe) is a familiar model to application developers. It's a middleware staple that's been used for a very long time to distribute messages to a variable set of systems. In a nutshell, PubSub is based on the notion of there existing a "queue" to which authorized components can publish events or messages of interest and to which interested components an subscribe. Events or messages have a life (like a TTL) and eventually expire. In the interim, it's expected that subscribed components check the queue for messages periodically. They poll for events or messages.

The queue itself is much like a switch or router's queue, except messages in the queue are duplicated until the TTL runs out and the message expires.

PubSub is passive; that is, it does not actively distribute messages. It merely serves as a kind of centralized repository, making available to those components that need it access to relevant information about the state of applications and/or the network.

Centralized Control Model

push-modelOpenFlow-based SDN, by contrast, is active. That is, it not only serves as a centralized repository for the state of applications and/or the network, but it actively distributes messages to components based on events. For example, a controller might receive a message from another system indicating the launch of a new application instance. That event triggers a series of actions on the controller that includes informing the affected network components of configuration changes. In a passive, PubSub model, the network components themselves might be polling for such an event and, upon receiving one, would initiate the appropriate configuration changes themselves.

We can simplify the description of the differences even more: a controller-based architecture uses a push model, while a pubsub-based architecture uses a pull model. What this doesn't illustrate well is that in a push model, the centralized controller must know how to communicate the desired changes to each and every component it is controlling. That's one of the reasons original models standardized on OpenFlow and were tightly focused on L2-4 stateless networking. It could be easily standardized down to a common forwarding table.While different components might internalize that differently, the basic information was always the same: IP addresses, ports and actions.

As we move up the stack into L4-7 stateful networking, however, this model becomes more burdensome because of the complexity of rule sets and differences in policy models across such a broad set of networking domains. Hence the plug-in support in controllers like OpenDaylight for "other" control protocols. But the basic premise of the model remains the same, regardless of the control protocol: the centralized controller dictates the changes to all components. It pushes those changes to the network. Both control and execution are centralized. The controller tells components to change their configuration.

PubSub centralizes control but decentralizes execution. The control plane is still centralized; there is one authoritative system responsible for disseminating change across the network, but each individual component (or domain controller but we'll get to that in a minute) is responsible for executing the appropriate changes based on their configured policies and services. A pubsub controller never tells a component "change this now"; that's up to the individual components (or domain controller).

The Integrated Control Model

To make things even more confusing (and disruptive), these models may be used simultaneously. A software-defined architecture might be based on a centralized control model with domain controllers for specific networking functions (like security and application delivery) integrated via a pubsub-based model.

integrated-model

This is where we start seeing models that combine emerging technologies like OpenStack and SDN architectures together. OpenStack manages at the data center level, and at its heart is pubsub model that can be used by domain controllers (stateless L2-4 SDN, stateful L4-7 SDN, etc...) to receive notification of changes in the network and subsequently push those changes using the appropriate control protocols to the components it is managing.

Needless to say, the term "disruptive" is really inadequate in describing the level of change in the network required to support either models (or both). Both require significant changes not just to the network itself but the way in which the network is fundamentally provisioned and managed. It's not just a new CLI or management console, these models dramatically change the design and management of networks.

Read the original blog entry...

More Stories By Lori MacVittie

Lori MacVittie is responsible for education and evangelism of application services available across F5’s entire product suite. Her role includes authorship of technical materials and participation in a number of community-based forums and industry standards organizations, among other efforts. MacVittie has extensive programming experience as an application architect, as well as network and systems development and administration expertise. Prior to joining F5, MacVittie was an award-winning Senior Technology Editor at Network Computing Magazine, where she conducted product research and evaluation focused on integration with application and network architectures, and authored articles on a variety of topics aimed at IT professionals. Her most recent area of focus included SOA-related products and architectures. She holds a B.S. in Information and Computing Science from the University of Wisconsin at Green Bay, and an M.S. in Computer Science from Nova Southeastern University.

@ThingsExpo Stories
In his general session at 19th Cloud Expo, Manish Dixit, VP of Product and Engineering at Dice, discussed how Dice leverages data insights and tools to help both tech professionals and recruiters better understand how skills relate to each other and which skills are in high demand using interactive visualizations and salary indicator tools to maximize earning potential. Manish Dixit is VP of Product and Engineering at Dice. As the leader of the Product, Engineering and Data Sciences team at D...
SYS-CON Events has announced today that Roger Strukhoff has been named conference chair of Cloud Expo and @ThingsExpo 2017 New York. The 20th Cloud Expo and 7th @ThingsExpo will take place on June 6-8, 2017, at the Javits Center in New York City, NY. "The Internet of Things brings trillions of dollars of opportunity to developers and enterprise IT, no matter how you measure it," stated Roger Strukhoff. "More importantly, it leverages the power of devices and the Internet to enable us all to im...
Whether your IoT service is connecting cars, homes, appliances, wearable, cameras or other devices, one question hangs in the balance – how do you actually make money from this service? The ability to turn your IoT service into profit requires the ability to create a monetization strategy that is flexible, scalable and working for you in real-time. It must be a transparent, smoothly implemented strategy that all stakeholders – from customers to the board – will be able to understand and comprehe...
"Once customers get a year into their IoT deployments, they start to realize that they may have been shortsighted in the ways they built out their deployment and the key thing I see a lot of people looking at is - how can I take equipment data, pull it back in an IoT solution and show it in a dashboard," stated Dave McCarthy, Director of Products at Bsquare Corporation, in this SYS-CON.tv interview at @ThingsExpo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
What happens when the different parts of a vehicle become smarter than the vehicle itself? As we move toward the era of smart everything, hundreds of entities in a vehicle that communicate with each other, the vehicle and external systems create a need for identity orchestration so that all entities work as a conglomerate. Much like an orchestra without a conductor, without the ability to secure, control, and connect the link between a vehicle’s head unit, devices, and systems and to manage the ...
Complete Internet of Things (IoT) embedded device security is not just about the device but involves the entire product’s identity, data and control integrity, and services traversing the cloud. A device can no longer be looked at as an island; it is a part of a system. In fact, given the cross-domain interactions enabled by IoT it could be a part of many systems. Also, depending on where the device is deployed, for example, in the office building versus a factory floor or oil field, security ha...
Amazon has gradually rolled out parts of its IoT offerings in the last year, but these are just the tip of the iceberg. In addition to optimizing their back-end AWS offerings, Amazon is laying the ground work to be a major force in IoT – especially in the connected home and office. Amazon is extending its reach by building on its dominant Cloud IoT platform, its Dash Button strategy, recently announced Replenishment Services, the Echo/Alexa voice recognition control platform, the 6-7 strategic...
Everyone knows that truly innovative companies learn as they go along, pushing boundaries in response to market changes and demands. What's more of a mystery is how to balance innovation on a fresh platform built from scratch with the legacy tech stack, product suite and customers that continue to serve as the business' foundation. In his General Session at 19th Cloud Expo, Michael Chambliss, Head of Engineering at ReadyTalk, discussed why and how ReadyTalk diverted from healthy revenue and mor...
As data explodes in quantity, importance and from new sources, the need for managing and protecting data residing across physical, virtual, and cloud environments grow with it. Managing data includes protecting it, indexing and classifying it for true, long-term management, compliance and E-Discovery. Commvault can ensure this with a single pane of glass solution – whether in a private cloud, a Service Provider delivered public cloud or a hybrid cloud environment – across the heterogeneous enter...
You have great SaaS business app ideas. You want to turn your idea quickly into a functional and engaging proof of concept. You need to be able to modify it to meet customers' needs, and you need to deliver a complete and secure SaaS application. How could you achieve all the above and yet avoid unforeseen IT requirements that add unnecessary cost and complexity? You also want your app to be responsive in any device at any time. In his session at 19th Cloud Expo, Mark Allen, General Manager of...
Financial Technology has become a topic of intense interest throughout the cloud developer and enterprise IT communities. Accordingly, attendees at the upcoming 20th Cloud Expo at the Javits Center in New York, June 6-8, 2017, will find fresh new content in a new track called FinTech.
The 20th International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held June 6-8, 2017, at the Javits Center in New York City, brings together Cloud Computing, Big Data, Internet of Things, DevOps, Containers, Microservices and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding business opportunity. Submit your speaking proposal ...
Bert Loomis was a visionary. This general session will highlight how Bert Loomis and people like him inspire us to build great things with small inventions. In their general session at 19th Cloud Expo, Harold Hannon, Architect at IBM Bluemix, and Michael O'Neill, Strategic Business Development at Nvidia, discussed the accelerating pace of AI development and how IBM Cloud and NVIDIA are partnering to bring AI capabilities to "every day," on-demand. They also reviewed two "free infrastructure" pr...
Unsecured IoT devices were used to launch crippling DDOS attacks in October 2016, targeting services such as Twitter, Spotify, and GitHub. Subsequent testimony to Congress about potential attacks on office buildings, schools, and hospitals raised the possibility for the IoT to harm and even kill people. What should be done? Does the government need to intervene? This panel at @ThingExpo New York brings together leading IoT and security experts to discuss this very serious topic.
More and more brands have jumped on the IoT bandwagon. We have an excess of wearables – activity trackers, smartwatches, smart glasses and sneakers, and more that track seemingly endless datapoints. However, most consumers have no idea what “IoT” means. Creating more wearables that track data shouldn't be the aim of brands; delivering meaningful, tangible relevance to their users should be. We're in a period in which the IoT pendulum is still swinging. Initially, it swung toward "smart for smar...
"Dice has been around for the last 20 years. We have been helping tech professionals find new jobs and career opportunities," explained Manish Dixit, VP of Product and Engineering at Dice, in this SYS-CON.tv interview at 19th Cloud Expo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
"ReadyTalk is an audio and web video conferencing provider. We've really come to embrace WebRTC as the platform for our future of technology," explained Dan Cunningham, CTO of ReadyTalk, in this SYS-CON.tv interview at WebRTC Summit at 19th Cloud Expo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
"At ROHA we develop an app called Catcha. It was developed after we spent a year meeting with, talking to, interacting with senior citizens watching them use their smartphones and talking to them about how they use their smartphones so we could get to know their smartphone behavior," explained Dave Woods, Chief Innovation Officer at ROHA, in this SYS-CON.tv interview at 19th Cloud Expo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
WebRTC is the future of browser-to-browser communications, and continues to make inroads into the traditional, difficult, plug-in web communications world. The 6th WebRTC Summit continues our tradition of delivering the latest and greatest presentations within the world of WebRTC. Topics include voice calling, video chat, P2P file sharing, and use cases that have already leveraged the power and convenience of WebRTC.
The many IoT deployments around the world are busy integrating smart devices and sensors into their enterprise IT infrastructures. Yet all of this technology – and there are an amazing number of choices – is of no use without the software to gather, communicate, and analyze the new data flows. Without software, there is no IT. In this power panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, Dave McCarthy, Director of Products at Bsquare Corporation; Alan Williamson, Principal...