Home Connected

Part 1: Storage as a Service – Clouds of Data

Welcome back, readers.  It’s been a while since I have been online, the past several months have been quite busy.  And now summer is over, the kids are back in school, and Avaya’s new fiscal year is about to begin in a couple of weeks.

A couple of weeks ago, Avaya made its first appearance at VMworld in Las Vegas, sharing a booth with one of our reseller partners, CRI (Communications Solutions Inc) of Red Bank, NJ.  CRI has taken many of the Aura components and applications, and virtualized them so they are able to run in as VMWare virtual machines.  Really impressive work.  And left some of us to wonder what other cloud services you, our interested readers, might like to hear about.  So, this week we are starting a four-part series on Storage as a Service with guest blogger, Ed Koehler, one of our most talented and knowledgeable systems engineers.

Ed has 23 years in the networking industry.  He has held various roles from being a regional Systems Engineer to being an Area and Theater Specialist expert for Network Management, Video, IP Multicast and IPv6.  For eight years, Ed was a member of the CTO group at Nortel as a Senior Technology Architect and expanded his expertise in Digital Identity and Management. Ed served as a subject matter expert to the ITU-T and presented on major issues of both identity and federation in Geneva, Switzerland on several occasions.
In his spare time, Ed authored eight patents on IPv6, Security, Identity and Federation. Ed also has several years as a dedicated SAN and Data Center consultant for large enterprises.  Ed is an evangelist on SPB (Shortest Path Bridging) and how we leverage that technology in our networking solutions fabric.  He is currently a US Theater expert in Avaya Virtual Enterprise Network Architecture and SPB supported by Brian Smith of the US Theater Networking Consulting SE team.

And now, here is Ed’s first installment of Storage as a Service – Clouds of Data.


Storage as a Service (SaaS) - How in the world do you? There is a very good reason why cloud storage has so much hype. It simply makes sense. It has an array of attractive use case models. It has a wide range of potential scope and purpose making it as flexible as the meaning of the bits stored. But most importantly, it has a good business model that has attracted some major names into the market sector. If you read the blog posts and articles, most will say that Cloud Storage will never be accepted due to the lack of security & accountability. The end result is that many CISO's & CIO's have decided that it is just too difficult to prove due diligence for compliance. As a result, they have not widely embraced the cloud model. Now while this is correct, it is not totally true. As a matter of fact most folks are actually using Cloud Storage within their environment. They just don't equate it as such. This article is intended to provide some insight into the use models of SaaS as well as some of the technical and business considerations that need to be made in moving to a SaaS environment.

Types of SaaS Clouds

It is commonly accepted that there are two types of clouds; public and private. It is the position of this architect that there are in reality three major types of clouds and a wide range of manifestations of them. There are reasons for this logic and the following definitions will clarify why. Public SaaS Clouds
Public clouds are clouds that are provided by open internet service providers. They are truly public in that they are equally available to anyone who is willing to put down a credit card number and post data to the repository. Examples of this are Google, Amazon & Storage Planet. While this is a popular model, as attested by its use, many are saying the honeymoon is fading along with issues of accountability, reports of lost data and lack of assurances for security and integrity of content. Semi-Private SaaS Clouds
These are clouds that are more closed in that they usually require some sort of membership or prior business subscribership. As a result the service is typically less open to the general public. Also, the definition of semi-private can have a wide range of embodiments. Examples are, network service providers like cable and telco companies, then slightly more closed might be an educational clouds for higher education to store, post and share vast quantities of content; finally the most closed would be government usage where say in the example of a county that provides a SaaS cloud service to the various agencies within its area of coverage.

Private SaaS Clouds
These are the truly private SaaS services that are totally owned and supported by a single organization. The environment is totally closed to the outside world and access is typically controlled with the same level of diligence as corporate resource access. The usual requirements are that the user has secure credentials and his department is accounted for usage by some of type of cost center. As indicated earlier these can occur in a variety of embodiments and in reality there is no hard categorization between them. Rather a continuum of characteristics that range from truly private to truly public. While placing data up into a truly public cloud would cause most CISO's and CIO's to cringe, many are finding that semi-private and private clouds are totally acceptable in dealing with issues of integrity, security and compliance. Concern about security and integrity of content is one thing. Another more teasing issue is knowing exactly where your data is in the cloud. Is it in New York? California? Canada? Additionally, if the SaaS provider is doing due diligence in protecting your data then they are replicating it to a secondary site. Where is that? India? As you can see in a totally public cloud service there are a big set of issues that prevent large scale serious use. Additionally, often performance is a real issue. This is particularly the case for critical data or for system restores, when the disappointed systems administrator finds that it will be a day and a half before the system is back on line and operational. These are serious issues that are not easily addressable in a true public cloud environment. Semi-private and Private Clouds on the other hand can often answer these requirements and can provide fairly solid reporting about the security and location of posted content. The important thing to realize is that it is not all or nothing. A single organization may use multiple clouds for various purposes, each with a different range of scope and usage. As an example, the figure below shows a single organization that has two private clouds one of which are used exclusively by a single department and one of which spans the whole organization. Additionally, that same organization may have semi-private clouds that are used for B2B exchange of data for use in partnerships, channel relationships, etc. Then finally, the organization may have an e-Commerce site that provides a fairly open public cloud service for its customer and prospect communities.
Part 1 figure1SaS.jpg
Figure 1. Multiple-tiered Clouds If you really boil it down, you come to a series of tiered security environments that control what type of data gets posted, by whom and for what purpose. Other issues include data type and size as well as performance expectations. Again, in a Semi-private to private usage model these issues can effectively be addressed in a fashion that satisfies both user and provider. The less public the service, the more stringent the controls for access and data movement and the tighter the security boundaries with the outside world. It is for this reason that I think truly public SaaS clouds have too much stacked against them to be taken as a serious tool for large off site data repositories. Rather, I think that organizations and enterprises will more quickly embrace semi-private and private Cloud storage because of the more tractable environment to address the issues mentioned earlier. There are also different levels of SaaS offerings. These can vary in complexity and offered value. As an example, a network drive service might be handy for storing extra data copies but might not be too handy as a tool for disaster recovery. As a result, most SaaS offerings can be broken into three major categories.
  • Low level - Simple Storage Target
  • Easy to implement
  • Low integration requirements
  • Simple network drive
  • Mid level - Enhanced Storage Target
  • VTL or D2D
  • iSCSI
  • Good secondary 'off-site' use model
  • High level - Hosted Disaster Recovery
  • VM failover
  • P2V Consistency Groups
  • Attractive to SMB sector
As one moves from one level to the next the need for more control and security becomes more important. As a result, the higher the level of SaaS offering the more private it needs to be in order to satisfy security and regulatory requirements.


The Value of the First Point of Presence in SaaS
As traffic leaves a particular organization or enterprise it enters either a private WAN and at some point there is boundary to the public Internet. Often these networks are depicted as clouds. We of course realize that there is in reality a topology of networking elements that handle the various issues of data movement. These devices are often switches or routers that operate at L2 or L3 and each imposes a certain amount of latency to the traffic as it moves from one point to another. As are result, the latency profiles to access data in a truly public SaaS becomes longer and less predictable due to increasing variables. The figure below illustrates this effect. As data traverses across the Internet it intermixes with other data flows at the various points of presence where these network elements route and forward data.
Part 1 figure2SaS.jpg
Figure 2. Various 'Points of Presence' for SaaS In a semi-private or a private cloud offering, the situation is much more controlled. In the case of a network provider, they are the very first point of presence or 'hop' that their customer's traffic crosses. It only makes sense that hosting a SaaS service at that POP will offer significantly better and more controlled latency and as a result far better throughput than will a public cloud service somewhere on the network. Also consider that the bandwidth of the connection to that first POP will be much higher than the average aggregate bandwidth that would be realized to the public storage provider on the Internet. If we move to a private cloud environment such as that hosted by a University as a billed tuition service for its student population, very high bandwidth can be realized with no WAN technologies involved. Obviously, the end to end latency in this type of scenario will be minimal when compared to pushing the data. This in addition to the security and control issues mentioned above will in the opinion of the author result in the dramatic growth in semi-private and private SaaS. Ed Koehler

William Seifert is the former Chief Technology Officer of Data Solutions at Avaya. He has served on numerous corporate boards, and holds a Bachelor and Master of Science, Electrical Engineering from Michigan State University. more

Leave a Reply