Click here to close now.

Welcome!

SAP Authors: Elizabeth White, Liz McMillan, Plutora Blog, Carmen Gonzalez, Automic Blog

Blog Feed Post

It's On: Stacks versus Flows

#OpenStack #CloudStack #OpenFlow #SDN It's a showdown of model versus control – or is it?

 

stack-vs-flow

There's a lot of noise about "wars" in the networking world these days. OpenStack versus CloudStack versus OpenFlow-based SDN.

But while there are definitely aspects of "stacks" that share similarities with "flows", they are not the same model and ultimately they aren't even necessarily attempting to solve the same problems.

Understanding the two models and what they're intended to do can go a long way toward resolving any perceived conflicts.

The Stack Model

Stack models, such as CloudStack and OpenStack, are more accurately placed in the category of "cloud management frameworks" because they are designed with provisioning and management of the infrastructure services that comprise a cloud computing (or highly dynamic) environment.

Stacks are aptly named as they attempt to provide management and specifically automation of provisioning for the complete network stack. Both CloudStack and OpenStack, along with Eucalyptus and Amazon and VMware vCloud, provide a framework API that can (ostensibly) be used to provision infrastructure services irrespective of vendor implementation. The vision is (or should be) to enable implementers (whether service provider or enterprise) to be able to switch out architectural elements (routers, switches, hypervisors, load balancers, etc… ) transparently*. That is, moving from Dell to HP to Cisco (or vice-versa) as an environment's switching fabric should not be disruptive. Physical changes should be able to occur without impacting the provisioning and management of the actual services provided by the infrastructure.

And yes, such a strategy should also allow heterogeneity of infrastructure.

In many ways, such "stacks" are the virtualization of the data center, enabling abstraction of the actual implementation from the configuration and automation of the hardware (or software) elements. This, more than anything, is what enables a comparison with flow-based models.

The Flow Model

Flow-based models, in particular OpenFlow-based SDN, also abstracts implementation from configuration by decoupling the control plane from the data plane. This allows any OpenFlow-enabled device (mostly switches today, as SDN and OpenFlow focus on network layers) to be configured and managed via a centralized controller using a common API.

Flows are "installed" or "inserted" into OpenFlow-enabled elements via OpenFlow, an open protocol designed for this purpose, and support real-time updates that enable on-demand optimization or fault isolation of flows through the network. OpenFlow and SDN are focused on managing the flow of traffic through a network. 

Flow-based models purport to offer the same benefits as a stack model in terms of heterogeneity and interoperability. Moving from one OpenFlow-enabled switch to another (or mixing and matching) should ostensibly have no impact on the network whatsoever.

What flow-based models offer above and beyond a stack model is extensibility. OpenFlow-based SDN models using a centralized controller also carry with it the premise of being able to programmatically add new services to the network without vendor assistance. "Applications" deployed on an SDN controller platform (for lack of a better term) can extend existing services or add new ones and there is no need to change anything in the network fabric, because ultimately every "application" distills flows into a simple forwarding decision that can then be applied like a pattern to future flows by the switches.

The Differences

This is markedly different from the focus of a stack, which is on provisioning and management, even though both may be occurring in real-time. While it's certainly the case that through the CloudStack API you can create or delete port forwarding rules on a firewall, these actions are pushed (initiated) external to the firewall. It is not the case that the firewall receives a packet and asks the cloud framework for the appropriate action, which is the model in play for a switch in an OpenFlow-based SDN.

Another (relatively unmentioned but important) distinction is who bears responsibility for integration. A stack-based model puts the onus on the stack to integrate (via what are usually called "plug-ins" or "drivers") with the component's existing API (assuming one exists). A flow-based model requires the vendor to take responsibility for enabling OpenFlow support natively. Obviously the ecosystem of available resources to perform integration is a magnitude higher with a stack model than with a flow model. While vendors are involved in development of drivers/plug-ins for stacks now, the impact on the product itself is minimal, if any at all, because the integration occurs external to the component. Enabling native OpenFlow support on components requires a lot more internal resources be directed at such a project.

Do these differences make for an either-or choice?

Actually, they don't. The models are not mutually exclusive and, in fact, might be used in conjunction with one another quite well. A stack based approach to provisioning and management might well be complemented by an OpenFlow SDN in which flows through the network can be updated in real time or, as is often proffered as a possibility, the deployment of new protocols or services within the network.

The War that Isn't

While there certainly may be a war raging amongst the various stack models, it doesn't appear that a war between OpenFlow and *-Stack is something that's real or ever will be The two foci are very different, and realistically the two could easily be deployed in the same network and solve multiple problems. Network resources may be provisioned and initially configured via a stack but updated in real-time or extended by an SDN controller, assuming such network resources were OpenFlow-enabled in the first place.

 

* That's the vision (and the way it should be) at least. Reality thus far is that the OpenStack API doesn't support most network elements above L3 yet, and CloudStack is tightly coupling API calls to components, rendering this alleged benefit well, not a benefit at all, at least at L4 and above. 


Connect with Lori: Connect with F5:
o_linkedin[1] google  o_rss[1] o_twitter[1]   o_facebook[1] o_twitter[1] o_slideshare[1] o_youtube[1] google

Related blogs & articles:


 

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
GENBAND has announced that SageNet is leveraging the Nuvia platform to deliver Unified Communications as a Service (UCaaS) to its large base of retail and enterprise customers. Nuvia’s cloud-based solution provides SageNet’s customers with a full suite of business communications and collaboration tools. Two large national SageNet retail customers have recently signed up to deploy the Nuvia platform and the company will continue to sell the service to new and existing customers. Nuvia’s capabilities include HD voice, video, multimedia messaging, mobility, conferencing, Web collaboration, deskt...
The WebRTC Summit 2014 New York, to be held June 9-11, 2015, at the Javits Center in New York, NY, announces that its Call for Papers is open. Topics include all aspects of improving IT delivery by eliminating waste through automated business models leveraging cloud technologies. WebRTC Summit is co-located with 16th International Cloud Expo, @ThingsExpo, Big Data Expo, and DevOps Summit.
SYS-CON Media announced today that @WebRTCSummit Blog, the largest WebRTC resource in the world, has been launched. @WebRTCSummit Blog offers top articles, news stories, and blog posts from the world's well-known experts and guarantees better exposure for its authors than any other publication. @WebRTCSummit Blog can be bookmarked ▸ Here @WebRTCSummit conference site can be bookmarked ▸ Here
SYS-CON Events announced today that Cisco, the worldwide leader in IT that transforms how people connect, communicate and collaborate, has been named “Gold Sponsor” of SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Cisco makes amazing things happen by connecting the unconnected. Cisco has shaped the future of the Internet by becoming the worldwide leader in transforming how people connect, communicate and collaborate. Cisco and our partners are building the platform for the Internet of Everything by connecting the...
Temasys has announced senior management additions to its team. Joining are David Holloway as Vice President of Commercial and Nadine Yap as Vice President of Product. Over the past 12 months Temasys has doubled in size as it adds new customers and expands the development of its Skylink platform. Skylink leads the charge to move WebRTC, traditionally seen as a desktop, browser based technology, to become a ubiquitous web communications technology on web and mobile, as well as Internet of Things compatible devices.
SYS-CON Events announced today that robomq.io will exhibit at SYS-CON's @ThingsExpo, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. robomq.io is an interoperable and composable platform that connects any device to any application. It helps systems integrators and the solution providers build new and innovative products and service for industries requiring monitoring or intelligence from devices and sensors.
Wearable technology was dominant at this year’s International Consumer Electronics Show (CES) , and MWC was no exception to this trend. New versions of favorites, such as the Samsung Gear (three new products were released: the Gear 2, the Gear 2 Neo and the Gear Fit), shared the limelight with new wearables like Pebble Time Steel (the new premium version of the company’s previously released smartwatch) and the LG Watch Urbane. The most dramatic difference at MWC was an emphasis on presenting wearables as fashion accessories and moving away from the original clunky technology associated with t...
Docker is an excellent platform for organizations interested in running microservices. It offers portability and consistency between development and production environments, quick provisioning times, and a simple way to isolate services. In his session at DevOps Summit at 16th Cloud Expo, Shannon Williams, co-founder of Rancher Labs, will walk through these and other benefits of using Docker to run microservices, and provide an overview of RancherOS, a minimalist distribution of Linux designed expressly to run Docker. He will also discuss Rancher, an orchestration and service discovery platf...
SYS-CON Events announced today that Akana, formerly SOA Software, has been named “Bronze Sponsor” of SYS-CON's 16th International Cloud Expo® New York, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. Akana’s comprehensive suite of API Management, API Security, Integrated SOA Governance, and Cloud Integration solutions helps businesses accelerate digital transformation by securely extending their reach across multiple channels – mobile, cloud and Internet of Things. Akana enables enterprises to share data as APIs, connect and integrate applications, drive part...
SYS-CON Events announced today that Vitria Technology, Inc. will exhibit at SYS-CON’s @ThingsExpo, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Vitria will showcase the company’s new IoT Analytics Platform through live demonstrations at booth #330. Vitria’s IoT Analytics Platform, fully integrated and powered by an operational intelligence engine, enables customers to rapidly build and operationalize advanced analytics to deliver timely business outcomes for use cases across the industrial, enterprise, and consumer segments.
SYS-CON Events announced today that Solgenia will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY, and the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Solgenia is the global market leader in Cloud Collaboration and Cloud Infrastructure software solutions. Designed to “Bridge the Gap” between Personal and Professional Social, Mobile and Cloud user experiences, our solutions help large and medium-sized organizations dr...
SYS-CON Events announced today that Liaison Technologies, a leading provider of data management and integration cloud services and solutions, has been named "Silver Sponsor" of SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York, NY. Liaison Technologies is a recognized market leader in providing cloud-enabled data integration and data management solutions to break down complex information barriers, enabling enterprises to make smarter decisions, faster.
Cloud is not a commodity. And no matter what you call it, computing doesn’t come out of the sky. It comes from physical hardware inside brick and mortar facilities connected by hundreds of miles of networking cable. And no two clouds are built the same way. SoftLayer gives you the highest performing cloud infrastructure available. One platform that takes data centers around the world that are full of the widest range of cloud computing options, and then integrates and automates everything. Join SoftLayer on June 9 at 16th Cloud Expo to learn about IBM Cloud's SoftLayer platform, explore se...
@ThingsExpo has been named the Top 5 Most Influential M2M Brand by Onalytica in the ‘Machine to Machine: Top 100 Influencers and Brands.' Onalytica analyzed the online debate on M2M by looking at over 85,000 tweets to provide the most influential individuals and brands that drive the discussion. According to Onalytica the "analysis showed a very engaged community with a lot of interactive tweets. The M2M discussion seems to be more fragmented and driven by some of the major brands present in the M2M space. This really allows some room for influential individuals to create more high value inter...
The world's leading Cloud event, Cloud Expo has launched Microservices Journal on the SYS-CON.com portal, featuring over 19,000 original articles, news stories, features, and blog entries. DevOps Journal is focused on this critical enterprise IT topic in the world of cloud computing. Microservices Journal offers top articles, news stories, and blog posts from the world's well-known experts and guarantees better exposure for its authors than any other publication. Follow new article posts on Twitter at @MicroservicesE
SYS-CON Events announced today the IoT Bootcamp – Jumpstart Your IoT Strategy, being held June 9–10, 2015, in conjunction with 16th Cloud Expo and Internet of @ThingsExpo at the Javits Center in New York City. This is your chance to jumpstart your IoT strategy. Combined with real-world scenarios and use cases, the IoT Bootcamp is not just based on presentations but includes hands-on demos and walkthroughs. We will introduce you to a variety of Do-It-Yourself IoT platforms including Arduino, Raspberry Pi, BeagleBone, Spark and Intel Edison. You will also get an overview of cloud technologies s...
SYS-CON Events announced today that SafeLogic has been named “Bag Sponsor” of SYS-CON's 16th International Cloud Expo® New York, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. SafeLogic provides security products for applications in mobile and server/appliance environments. SafeLogic’s flagship product CryptoComply is a FIPS 140-2 validated cryptographic engine designed to secure data on servers, workstations, appliances, mobile devices, and in the Cloud.
Containers and microservices have become topics of intense interest throughout the cloud developer and enterprise IT communities. Accordingly, attendees at the upcoming 16th Cloud Expo at the Javits Center in New York June 9-11 will find fresh new content in a new track called PaaS | Containers & Microservices Containers are not being considered for the first time by the cloud community, but a current era of re-consideration has pushed them to the top of the cloud agenda. With the launch of Docker's initial release in March of 2013, interest was revved up several notches. Then late last...
SOA Software has changed its name to Akana. With roots in Web Services and SOA Governance, Akana has established itself as a leader in API Management and is expanding into cloud integration as an alternative to the traditional heavyweight enterprise service bus (ESB). The company recently announced that it achieved more than 90% year-over-year growth. As Akana, the company now addresses the evolution and diversification of SOA, unifying security, management, and DevOps across SOA, APIs, microservices, and more.
After making a doctor’s appointment via your mobile device, you receive a calendar invite. The day of your appointment, you get a reminder with the doctor’s location and contact information. As you enter the doctor’s exam room, the medical team is equipped with the latest tablet containing your medical history – he or she makes real time updates to your medical file. At the end of your visit, you receive an electronic prescription to your preferred pharmacy and can schedule your next appointment.