Software Defined Networking (SDN) A Review

Transcription

1 RESEARCH PAPER Software Defined Networking: The solution s here, but nobody s listening April 2014 Sponsored by

2 CONTENTS Executive summary Scoping the survey Surveying the network Planning for change The network without SDN The network with SDN A problem solved? A solution shunned Conclusion About the sponsor, HP p3 p3 p4 p6 p7 p8 p8 p9 p10 p11 This document is property of Incisive Media. Reproduction and distribution of this publication in any form without prior written permission is forbidden. 2 Computing research paper sponsored by HP

3 Executive summary Courtesy mainly of regular increases in raw bandwidth plus advances in traffic shaping and routing technology, networks have, until recently, managed to keep pace with most IT developments. However, that may not be true for much longer. Faced with the triple whammy of cloud computing, spiralling mobile demand and, more recently, the Internet of Things, infrastructures designed for an era of more modest and predictable traffic growth are starting to show their age and run out of steam. Not only are these trends becoming increasingly important and onerous and bear in mind we ve only seen the start of the Internet of Things so far they are all completely dependent on the underlying network technology. No network equals no cloud, no mobile apps, no BYOD or Internet of Things and, you might add, no big data, distributed computing, social media or any of those other good things. Forward thinking developers and vendors spotted this weak link some time ago and began to apply the same virtualisation technologies that revolutionised server processing and storage to the networks that connect servers, storage and clients together. As a result the major networking vendors have all lined up behind what has been dubbed Software Defined Networking (SDN) confident that it will be the next big thing rolling down the tracks and into the data centre. Customers, however, seem reluctant to give up their traditional network comfort blanket. Indeed it is fair to say that, apart from a few large data intensive sectors such as telecoms, SDN has yet to make its mark in the wider corporate world. Possibly because of an impression of it as a high-end solution suited only to telcos and other large organisations or, perhaps, because of worries over being locked into proprietary protocols, potential teething problems or the cost of having to rip and replace existing hardware. All of which is perplexing as, the issues SDN is designed to address are real and pressing with companies across the board actively looking for solutions and wanting them now. The aim of this white paper, therefore, is to firstly understand the networking problems companies face and the plans they have for addressing them. But secondly, to discuss how SDN can help, why vendors believe it should be a credible part of those plans and why customers appear not be listening. Scoping the survey This investigation into why Software Defined Networking has yet to capture the corporate imagination is based on an online survey of 100 Computing subscribers. Over half were from companies with 500 to over 5,000 employees, spread across multiple sectors from education and healthcare through banking to manufacturing and public sector organisations. Respondents were also selected as involved in the specification, deployment or management of networking technology and their organisations all had in-house server rooms or data centres of some description. Computing research paper sponsored by HP 3

4 Surveying the network Unsurprisingly the survey reflected widespread adoption of the kind of technologies now regarded as essential within the modern data centre. To this end the companies involved were found to employ multiple servers with 45 percent of respondents reporting populations of 100 or more across their localities. As might be expected, too, the use of server virtualisation now a very mature technology was equally widespread (Fig. 1), with virtualisation now very much a way of life for most. Fig. 1 : Physical and virtual severs HOW MANY PHYSICAL SERVERS DOES YOUR ORGANISATION OPERATE? 45% 9% 2% 2% 13% 15% Don t know 13% HOW MANY VIRTUAL SERVERS DOES YOUR ORGANISATION OPERATE? 48% 5% 11% 4% 4% 18% 12% Don t know 4 Computing research paper sponsored by HP

5 Looking further afield MPLS and VPLS were found to predominate when it came to wide area networking. Plus there was a high take-up of cloud services, despite the relative immaturity of the technologies and services available in this field. Indeed, around two-thirds reported routine deployment of some kind of cloud technology, with private clouds in the majority (52%) while 35 percent said they used public Software as a Service (SaaS) solutions and 12 percent Infrastructure as a Service (IaaS) implementations (Fig. 2). Fig. 2 : Which types of cloud computing does your organisation use? Private cloud Public cloud - SaaS Public cloud - IaaS Don t know Public cloud - Paas We don t use cloud 52% 35% 12% 7% 7% 28% *Respondents could select multiple answers. Respondents also reported good awareness of an even more recent trend that of Bring Your Own Device (BYOD) and the need to be clear as to where the organsiation stood on the connection of personal mobile devices to the corporate network. In fact over half (52%) said they had a BYOD or mobile access policy already with a further 23 percent planning to develop one over the next 12 months (Fig. 3, see next page). Computing research paper sponsored by HP 5

6 Fig. 3 : Do you have a BYOD or mobile access policy? 25% 52% Yes No but we are planning to within 12 months No 23% Again this was far from surprising and, as confirmed in other Computing surveys mobile access continues to be a major networking trend with machine-to-machine communication and the Internet of Things further adding to the burden being placed on network in infrastructures. Planning for change When asked if they were planning to upgrade their network infrastructures to cope with increasing complexity and demand, respondent answers were very illuminating. Not least because those definitely not doing so were in the minority. A mere 17 percent said they had no plans to upgrade their networks with a third (33%) planning an upgrade within 12 months, many sooner rather than later. Another 11 percent expected upgrades to get the green light within an 18 month window and a further 21 percent likely to follow suit thereafter (Fig. 4). Fig. 4 : Are you planning to upgrade your network infrastructure? 18% 7% 7% Yes within 3 months Yes within 6 months 17% 19% Yes within 12 months Yes within 18 months Yes at some point beyond 18 months No Don t know 20% 11% 6 Computing research paper sponsored by HP

7 When it came to reasons why they were upgrading the top two answers were the need to replace infrastructure at the end of its life, i.e. replacing old and outdated kit, and the perennial problem of needing more bandwidth. Better application performance was also cited with, as a result, the majority of upgrades reasonably likely to include the adoption of the latest 10GbE switching fabrics with many going further to 40GbE and beyond. Support for converged communications proved yet another popular reason for upgrading. And it is fairly safe to assume that many will also be enhancing and extending their wireless infrastructure to cope with burgeoning mobile demands, possibly switching to the new but now ratified ac technology, also referred to as Gigabit WiFi. Mergers and moving to larger (or in some cases smaller) data centres were among the other reasons why networks needed to be upgraded. Whatever the reason, however, the general picture is one of widespread and ongoing infrastructure upgrades in progress across the whole corporate spectrum. A picture which begs the question why, when it would seem like the ideal time to, at the very least, evaluate SDN, so few companies seem to be lining up to take advantage of what it has to offer? A mere six percent of respondents to the survey were actively considering SDN with a worrying 39 percent claiming that they had never heard of it, clearly highlighting the need for more education and marketing efforts from the vendors involved. Unfortunately we can t fill that void in one short white paper, but we can briefly summarise what SDN is all about and prompt a discussion as to how it can be used to address the issues causing such frenetic upgrading activity. The network without SDN If you re reading this then, chances are, you will be familiar with how traditional networks are constructed. Essentially the hardware involved is self-contained and does everything itself. Not just the physical switching and routing of network traffic but also the hosting of software to decide where, when and how that traffic should be directed, the priority given to different traffic streams, the level of security to apply and so on. In the jargon of the trade, every switch and every router on a network contains both a forwarding plane (to handle the physical task of forwarding network traffic) and a control plane (to manage how, when and where traffic is forwarded). The problem is that this integrated and self-contained approach doesn t scale well and, on larger deployments especially, can be very cumbersome. Not least because of the need for an additional layer of communication between switches and routers to make sure they all handle traffic in the same way, applying the same forwarding and security policies and so on. Changing the way the network is structured and works can, as a result, be a complex, labourintensive task with a high risk of service disruption. Plus, because the control plane operates in isolation on the forwarding hardware itself, the network lacks visibility and understanding of what it s being used for, particularly, when it comes to application requirements. Computing research paper sponsored by HP 7

8 The network with SDN On a network based on SDN technology the forwarding plane is dedicated solely to that one task forwarding traffic around the network. The control plane managing the process, meanwhile, is virtualised and implemented in software. This makes for a much more scalable and flexible network, for example allowing rapid, even, dynamic topology changes to be made without the need to over-provision ports as with traditional network architectures. Administration also becomes much simpler with SDN as traffic management and security policies only have to be defined once. Moreover, common management tasks can be automated and with visibility of network traffic at the application level, business logic used to manage network structure and behaviour. With SDN the network morphs from a static monolith to a much more fluid beast able to dynamically adapt to changes in demand. At least that s the theory. A problem solved? Of course there s a lot more to SDN than summarised above. But, assuming the benefits outlined, let s just consider how it stacks up when compared to what the recent Computing survey identified as the issues keeping network managers awake at night. As already mentioned, the top reasons for upgrading a network appear to be hardware coming to the end of its life and the need for more bandwidth. In which case it would seem logical to look at alternatives, like SDN, rather than simply continuing with more of the same stuff unable to meet current bandwidth needs, let alone cope with long term growth with any certainty. A further but less obvious inference to be made is the amount of change there is with continual and ongoing need for network upgrades just about everywhere. Networks need to change all the time, an issue SDN addresses by making it possible to restructure and add to the network without having to over provision up front or continually rip and replace infrastructure components simply to provide more bandwidth. SDN scores highly in that extra bandwidth can be dynamically assigned by the virtualised control plane and traffic flows prioritised to optimise the available switching capabilities. Plus, where extra hardware is needed, additions and changes can be made without the need for labourintensive cabling and complex configuration work. Next on the list, just over a third (35%) of respondents also highlighted a desire to improve application performance as a reason for upgrading their networks. By which, of course, most mean throwing bandwidth at the problem, which may or may not land on target. Similarly, although it is possible to logically segment and prioritise traffic on a conventional network, a great deal of experimentation and skill is required to get the right balance without disrupting existing levels of service. Again, this is an issue SDN is expressly designed to address, through APIs that allow the virtualised control plane to communicate directly with applications wanting to use the network. More than that, it can dynamically assign bandwidth and adapt the way traffic is prioritised to suit, and do so automatically using simple business-based policies to cope with new as well as existing application requirements. 8 Computing research paper sponsored by HP

9 Those respondents who said they were considering SDN seemed well aware of these benefits. Indeed, when asked why they were investigating SDN, the top answer was increased scalability and agility, followed by the ability to automate manual functions, increase network flexibility and make their networks application aware. Paradoxically, however, companies considering SDN at all were in the minority so of equal interest are the responses given by those not looking to deploy SDN in the near future. As already reported, over a third claimed not to have even heard of the term while the remainder highlighted a variety of misconceptions as well as general lack of understanding of the technologies involved. A solution shunned The top reason for eschewing SDN was a lack of in-house skills, but that would be the case with any new development and, by its very nature, managing an SDN infrastructure should be easier than having to grapple with a traditional set-up. A similar number also thought it too new a technology for them, while others saw it as too expensive or, more likely, that there was no clear ROI argument something vendors clearly need to address (Fig. 5). Fig. 5 : Why do you think you will not deploy SDN in the near future? Lack skills in house It s immature standards are not settled yet Too expensive, unclear ROI We d have to rip and replace our current infrastructure Other (please specify) It will add complexity in our multi-vendor environment Disruption and downtime while deploying It s only suitable for really big players, like telecoms companies Possible performance issues It s cumbersome to deploy 33% 31% 29% 22% 20% 16% 13% 11% 9% 7% *Respondents could select multiple answers. Computing research paper sponsored by HP 9

10 Others thought they would need to rip and replace their existing infrastructure to implement SDN. An argument that has an element of truth, but much the same claim could be levelled at a conventional network uplift. Moreover, the rejoinder from SDN vendors would be that, once on the SDN path, future changes should be much less disruptive. Similarly, any network upgrade can cause disruption and downtime yet another concern a risk that would, likewise, be greatly minimised post-sdn deployment. A mere 11 percent saw SDN as a high-end solution solely for big companies, indicating that part of the message at least seems to be getting through. A larger number, however, thought it would add complexity, especially in a multi-vendor environment. And that despite the majority of SDN vendors lining up to support open technologies and standards, such as OpenFlow from the Open Networking Foundation (ONF). Some respondents even imagined SDN to be little more than a marketing term, illustrating the breadth of ignorance that exists when it comes to what others see as the next big thing as far as networking is concerned. The networking vendors appear to have the answers, unfortunately their customers have yet to be convinced of the questions and just aren t listening. Conclusion The overriding inference to be drawn from the results of the Computing survey on which this white paper is based is that vendors keen to promote the benefits of SDN need to address what appears to be a fundamental paradox. Potential customers quite clearly exist and, quite clearly face issues when it comes to networking bandwidth, change management and application awareness that SDN is designed to address. At the very least, SDN ought to be on the list of possible upgrade paths for such customers, but that isn t the case. Instead a lack of awareness and understanding is leading those with the most to gain to stick with the devil they know and, some would say, perversely compound their problems by upgrading to more of the same rather than try what many see as a new and unknown quantity. Blame for this paradox needs to be apportioned equally. SDN is a relatively new technology and vendors, resellers and other experts could do a lot more to educate users, not just to the benefits but to the nuts and bolts of how SDN works, how best to implement it without disrupting services and how much it will actually cost. Customers, though need to work a little harder as well and take their heads out of the traditional network sand to discover not just what SDN can do for them but what they can do with SDN. Maybe then it really will become the next big thing and take what may claim as its rightful place in corporate datacentres everywhere. 10 Computing research paper sponsored by HP

11 About the sponsor, HP As a global leader in information technology, HP applies new thinking and ideas to help remove complexity and simplify technology experiences. We strive to continuously improve the way our customers live and work through sophisticated technology that is easy to use and manage. HP s quality engineering and reliable service and support gives all of our customers from individual consumers to the largest enterprises greater freedom to focus on their priorities and confidence to reach their goals. Because ultimately we know that each time we create a truly valuable experience, we are helping people achieve results that really count. For more information: Visit: Computing research paper sponsored by HP 11