|By Karthikeyan Subramaniam||
|May 3, 2013 03:11 PM EDT||
Software Defined Networking (SDN) has become a famous paradigm and also the bandwagon in the networking industry today. SDN is primarily considered to be a methodology or approach to solving some of the wider-known problems in the enterprise and service provider networking space. It's also a tool to create some exciting new features today. The term "Software Defined Networking" provides a green-field opportunity for vendors to define, promote and customize it in their own way. End users don't care so much about the definition; they are more concerned about its contribution in optimizing and solving real problems.
The initial protocol that is considered to be a precursor to SDN is "OpenFlow." Open Networking Foundation (ONF) defines SDN as a new approach to networking, whereby, network control is decoupled from the data-forwarding function and is directly programmable. OpenFlow allows the traditional layer 2 switches to examine headers in the packet/frame and make forwarding decisions. OpenFlow-supported switches examine the packet headers through the transport layers and can match more than 13 fields that span across layer 2 to layer 4.
How Exactly Is It Going to Be Useful?
There are some interesting use cases defined by various vendors that utilize the IP and TCP header look-up to make forwarding decisions. Even though these use cases are not fully established, they may be useful to perform traffic redirection and traffic engineering by merely using switches. Some practical uses of traffic engineering would be to isolate the malicious traffic at the switch level for further analysis and containment. Another example would be the ability to divert traffic through multiple ISP connections based on applications and specific computers (users). Many vendors are focusing on getting these use cases established by creating controllers and switches. Controllers push the rules onto the switches. Switches perform the packet processing, rule lookup and makes forwarding decisions. OpenFlow controllers and switches are considered to be the two main pieces of SDN by many vendors. Other software is currently being developed and promoted under the SDN umbrella such as Orchestration/Automation software.
Why Do We Need Orchestration/Automation Software?
Orchestration/automation software is primarily considered to be a component that sits on top of the controller and uses the controller's northbound APIs to execute sets of tasks in sequence based on events and monitoring. Usually these tasks are performed by scripts that run on either a time-bound or situation-bound way manually set in place by system administrators. As an example, scripts could be a weakened configuration script, a flash crowd-specific network, server configuration script, etc. It provides the ability to perform scenario-specific, time-specific, or business-policy-specific infrastructure setup and configuration. Orchestration software brings these scripts under a single umbrella of SDN and masks the error-prone programming needs from the system administrators to provide a user-friendly and easy-to-configure, easy-to-monitor graphical user interface.
One of the most important uses of Orchestration/Automation software is in cloud computing. The cloud is in essence a data center that runs services on top of physical servers directly or on virtual machines that share a single physical server and provides a user-friendly interface to manage the services, the virtual machines (VM), the servers and the whole infrastructure. The main idea behind consolidating the VMs on a single physical server is to maximize the utilization of the hardware resources that are invested and minimize the operational expenses (OPEX) such as energy costs by running the fewest possible physical servers for a given load. As loads increase, more VMs require enabling to balance the load and provide optimum service. Hardware virtualization software (hypervisors) makes the process of preserving a running operating system as a snapshot or image easy and automatic. When a snapshot is created as a virtual machine, it's important to get the underlying networking also reconfigured automatically. This is where OpenFlow comes into play to enable network virtualization.
Here's how it works. When the VM is booted up and sends the first Ethernet frame outbound, the switch captures it and sends layer 2 and layer 4 header information to the controller and checks where to forward the packets. Controller creates the dynamic "vlan-like" port grouping based on predefined policies using MAC addresses or IP addresses. Without any administrative intervention, the newly created VM is already part of the existing network and is part of the pre-configured load balancer server pool. This practical and exciting approach makes good use of the SDN. The automation is generally done through the hypervisor or management software that runs above the hypervisor. While this automation seems magical, there are some important points to consider.
What's the Catch?
Like expert magicians, SDN vendors misdirect the users about the features and opportunities of control and data plane separation while not revealing some important facts. When lots of promotional and inaccurate information about SDN prevails in the market, we should also learn to look behind the curtains to fully understand the price that is paid for the new features. When we look closely, the price of enabling OpenFlow is obvious; it's performance. Traditional switches are meant to look up the layer 2 fixed length headers. Conversely, OpenFlow switches look up variable length headers such as IP and TCP. While the effort to examine length-delimited lookup and parsing is obvious, there are some good readings that detail the performance penalties of handing variable length headers compared to fixed-length headers.
Although OpenFlow switches open up an exciting new approach and bring a huge momentum to the networking industry, the illusion of them replacing all the layer 2 switches will not hold up very well when you actually put them to test and compare the results. OpenFlow should complement the existing infrastructure and should not attempt to replace traditional switches since OpenFlow switches try to solve a different set of problems. Pricing what we pay to automatically detect the newly created VM or newly created application session is actually impacting the packet/frame forwarding performance immensely. While OpenFlow is still useful as traffic engineering and as a flow management tool, it should not be considered a replacement for a layer 2 switch. It's not just based on the OpenFlow protocol maturity at this point; it's based on its design itself.
One of the important aspects of the SDN that does not get much traction on the specifics is northbound APIs. While ‘application-oriented' and ‘application-defined' software and networking product promotions have been swamping the industry, this is really about engineering application traffic based on TCP port numbers. But correctly implemented northbound APIs can bridge the gap between the application and networking worlds. Industry brilliance should be applied to solve the real age-old problem: TCP. Applications utilize TCP. Application developers consider networking as a one big pipe of unlimited bandwidth and speed of light connectivity. Applications have limited visibility into the underlying networking or server infrastructure. In the SDN world, controller vendors are pondering and developing northbound APIs. Most controller developers are considering these APIs only as a CLI replacement. They are also viewing it as a southbound interface to another network automation or management software.
Let the Application Be the Controller
Think of the gravity hydro-dams. When counties around the state are requesting more water for irrigation, what happens if the dam's controller decides to honor every request for the needed amount? Should it open the water-gate to its fullest to serve all the required quantity without considering how much the distribution pipes can handle? Although most people will not think of doing this, this is exactly what is happening in the software world today.
When the application receives the incoming requests, it assumes the network has unlimited capacity and light-speed connectivity to the one making the request. Applications start creating packets by spending CPU, memory and disk resources. Later, the network optimization or QoS device finds out that the links are overused and decides to drop the packets to inform the applications to slow down. All of the resources consumed were not only going to waste, it also created more congestion on the network. Instead of using ancient smoke-signaling approaches like packet drops to inform the applications about the network congestion, SDN vendors should build more robust northbound APIs to provide more network visibility to the applications. It will be a paradigm shift in the way applications are developed. It will address the problem at its source. The promise relies on the simplicity and standardization of the northbound APIs.
Although the northbound APIs are not well defined and left for vendors to implement their own sets of rules, the power to make the SDN succeed lies in the northbound APIs. It is the real disruption in the industry not the data and control plane separation.
Northbound APIs for Policy Plane
As the controller's northbound API is to the underlying infrastructure, the needs for northbound APIs for the policy plane are also growing. Policies change all the time to align with business goals as they drive the infrastructure both directly and indirectly. When the policy plane also exposes the APIs for applications to consume the priorities and service level agreements (SLA), the same occurs between the forwarding plane and control plane today on the networking side.
Northbound APIs should allow the application to query the system, network, and server infrastructure to optimize the network globally. It should also be able to interact with the policy layer to get the priorities and SLA before committing to any resources. This will exceed the end user's investment on applications and networking infrastructure while avoiding shifting problems between each other and truly begin to collaborate and complement one another.
The real customers and end users want practical and usable solutions, not definitions. We should think beyond defining the jargon and start creating focused and useable solutions.
As organizations shift towards IT-as-a-service models, the need for managing & protecting data residing across physical, virtual, and now cloud environments grows with it. CommVault can ensure protection & E-Discovery of your data - whether in a private cloud, a Service Provider delivered public cloud, or a hybrid cloud environment – across the heterogeneous enterprise.
Nov. 29, 2015 06:00 PM EST Reads: 230
Today air travel is a minefield of delays, hassles and customer disappointment. Airlines struggle to revitalize the experience. GE and M2Mi will demonstrate practical examples of how IoT solutions are helping airlines bring back personalization, reduce trip time and improve reliability. In their session at @ThingsExpo, Shyam Varan Nath, Principal Architect with GE, and Dr. Sarah Cooper, M2Mi’s VP Business Development and Engineering, explored the IoT cloud-based platform technologies driving t...
Nov. 29, 2015 06:00 PM EST Reads: 439
In his General Session at DevOps Summit, Asaf Yigal, Co-Founder & VP of Product at Logz.io, explored the value of Kibana 4 for log analysis and provided a hands-on tutorial on how to set up Kibana 4 and get the most out of Apache log files. He examined three use cases: IT operations, business intelligence, and security and compliance. Asaf Yigal is co-founder and VP of Product at log analytics software company Logz.io. In the past, he was co-founder of social-trading platform Currensee, which...
Nov. 29, 2015 04:00 PM EST Reads: 251
The Internet of Things (IoT) is growing rapidly by extending current technologies, products and networks. By 2020, Cisco estimates there will be 50 billion connected devices. Gartner has forecast revenues of over $300 billion, just to IoT suppliers. Now is the time to figure out how you’ll make money – not just create innovative products. With hundreds of new products and companies jumping into the IoT fray every month, there’s no shortage of innovation. Despite this, McKinsey/VisionMobile data...
Nov. 29, 2015 02:00 PM EST Reads: 485
Culture is the most important ingredient of DevOps. The challenge for most organizations is defining and communicating a vision of beneficial DevOps culture for their organizations, and then facilitating the changes needed to achieve that. Often this comes down to an ability to provide true leadership. As a CIO, are your direct reports IT managers or are they IT leaders? The hard truth is that many IT managers have risen through the ranks based on their technical skills, not their leadership ab...
Nov. 29, 2015 01:00 PM EST Reads: 414
Just over a week ago I received a long and loud sustained applause for a presentation I delivered at this year’s Cloud Expo in Santa Clara. I was extremely pleased with the turnout and had some very good conversations with many of the attendees. Over the next few days I had many more meaningful conversations and was not only happy with the results but also learned a few new things. Here is everything I learned in those three days distilled into three short points.
Nov. 29, 2015 01:00 PM EST Reads: 353
DevOps is about increasing efficiency, but nothing is more inefficient than building the same application twice. However, this is a routine occurrence with enterprise applications that need both a rich desktop web interface and strong mobile support. With recent technological advances from Isomorphic Software and others, rich desktop and tuned mobile experiences can now be created with a single codebase – without compromising functionality, performance or usability. In his session at DevOps Su...
Nov. 29, 2015 12:45 PM EST Reads: 419
As organizations realize the scope of the Internet of Things, gaining key insights from Big Data, through the use of advanced analytics, becomes crucial. However, IoT also creates the need for petabyte scale storage of data from millions of devices. A new type of Storage is required which seamlessly integrates robust data analytics with massive scale. These storage systems will act as “smart systems” provide in-place analytics that speed discovery and enable businesses to quickly derive meaningf...
Nov. 29, 2015 12:30 PM EST Reads: 425
In his keynote at @ThingsExpo, Chris Matthieu, Director of IoT Engineering at Citrix and co-founder and CTO of Octoblu, focused on building an IoT platform and company. He provided a behind-the-scenes look at Octoblu’s platform, business, and pivots along the way (including the Citrix acquisition of Octoblu).
Nov. 29, 2015 12:00 PM EST Reads: 527
In his General Session at 17th Cloud Expo, Bruce Swann, Senior Product Marketing Manager for Adobe Campaign, explored the key ingredients of cross-channel marketing in a digital world. Learn how the Adobe Marketing Cloud can help marketers embrace opportunities for personalized, relevant and real-time customer engagement across offline (direct mail, point of sale, call center) and digital (email, website, SMS, mobile apps, social networks, connected objects).
Nov. 29, 2015 11:45 AM EST Reads: 327
The buzz continues for cloud, data analytics and the Internet of Things (IoT) and their collective impact across all industries. But a new conversation is emerging - how do companies use industry disruption and technology enablers to lead in markets undergoing change, uncertainty and ambiguity? Organizations of all sizes need to evolve and transform, often under massive pressure, as industry lines blur and merge and traditional business models are assaulted and turned upside down. In this new da...
Nov. 29, 2015 11:30 AM EST Reads: 275
In recent years, at least 40% of companies using cloud applications have experienced data loss. One of the best prevention against cloud data loss is backing up your cloud data. In his General Session at 17th Cloud Expo, Sam McIntyre, Partner Enablement Specialist at eFolder, presented how organizations can use eFolder Cloudfinder to automate backups of cloud application data. He also demonstrated how easy it is to search and restore cloud application data using Cloudfinder.
Nov. 29, 2015 10:00 AM EST Reads: 203
The Internet of Everything is re-shaping technology trends–moving away from “request/response” architecture to an “always-on” Streaming Web where data is in constant motion and secure, reliable communication is an absolute necessity. As more and more THINGS go online, the challenges that developers will need to address will only increase exponentially. In his session at @ThingsExpo, Todd Greene, Founder & CEO of PubNub, exploreed the current state of IoT connectivity and review key trends and t...
Nov. 29, 2015 09:45 AM EST Reads: 453
Two weeks ago (November 3-5), I attended the Cloud Expo Silicon Valley as a speaker, where I presented on the security and privacy due diligence requirements for cloud solutions. Cloud security is a topical issue for every CIO, CISO, and technology buyer. Decision-makers are always looking for insights on how to mitigate the security risks of implementing and using cloud solutions. Based on the presentation topics covered at the conference, as well as the general discussions heard between sessi...
Nov. 29, 2015 09:15 AM EST Reads: 345
We all know that data growth is exploding and storage budgets are shrinking. Instead of showing you charts on about how much data there is, in his General Session at 17th Cloud Expo, Scott Cleland, Senior Director of Product Marketing at HGST, showed how to capture all of your data in one place. After you have your data under control, you can then analyze it in one place, saving time and resources.
Nov. 29, 2015 08:45 AM EST Reads: 223