One of the key trends that we see is that the network architecture in the data center is changing, and quite rapidly.  It is also the network that is driving the purchase decisions in both the server market and in the storage systems market.

Our analysts recently discussed this topic.  Here is what they had to say.

Tam Dell’Oro:  Let’s talk about what you are seeing in network architecture in the data center.  What are the changes taking place?

Alan Weckel:  Sure, so I think the best way to look at this is to use a couple of specific examples.  First, look at enterprise architectures.  They really haven’t changed a great deal – the real difference here is that organizations are looking more at converged and integrated systems—that is putting servers, storage and networking together for ease of management and ease of use in deployments within enterprises.  So a natural speed migration from 1-to-10 Gbps, and storage and servers following a similar trend regarding speeds, with storage also having a decent amount of Fibre Channel attached.

If we look at the Cloud, or the large Cloud Providers, it’s a completely different architecture.  This is where the leaf spine starts to become very popular.  The largest Cloud Providers are migrating to 40 Gbps server access as we speak, and therefore, to 40 Gbps top-of-rack leaf switches.  That technology is all Ethernet, end-to-end; how it connects to servers, storage, and everything else.  Therefore, we have a completely different class of product and a completely different architecture driving the cloud.

But in each of these cases I’ve described, the network really is the focal decision point on how the data center is going to be built and architected.  All the components come together based on what the network can do and what the network can drive.

Tam Dell’Oro:  Sameh, please share your thoughts here. How do you see the data center network architecture impacting how servers are being purchased?

Sameh Boujelbene:  Well, as Alan has mentioned, when we look at the server market, we are really looking at two different segments that are completely divergent in terms of their requirements.  On one hand you have the Cloud—the Cloud is moving rapidly to higher speeds, and is already moving to 40 Gbps.  The cloud will also be the first to move to 25 Gbps, 50 Gbps, and 100 Gbps, and here mostly rack servers are being deployed.  In some cases they are also deploying rack scale architecture which is really disaggregating the compute nodes, from the storage nodes, from the network.  The compute nodes within this rack scale architecture can sometimes be accessed at 100 Gbps speeds.  Also for some types of highly scalable workloads, the cloud is using or deploying high density servers, shipping with either low speed or high speed connections and the network connection sometimes sits on the SoC or CPU, and sometimes it sits on separate adapter cards.  These are the common types of network deployment that go with the different server form factors within the Cloud market.

Server Migration Chart

On the other hand, we have the Enterprise market.  Most of the Enterprise servers are still on 1 Gbps.  They are starting to move to 10 Gbps on rack and tower servers and we see 40 Gbps only on the highly virtualized blade servers.  That is what we are seeing.

Tam Dell’Oro:  Chris, please share your thoughts about how the network architecture is impacting storage systems and how they are purchased.

Chris DePuy:  Thanks, Tam.  Yes, I’d like to share with you something that I find interesting, after listening to Alan and Sameh talk about 40 Gbps and other high speeds that we are seeing in the Cloud, it’s actually not what’s happening to the storage market.  If you look through our research in the storage systems report, you will see approximately no 40 Gbps in the storage market.

So, it begs the question…what’s going on?!  Well, in the Cloud, what we are seeing with the storage trends is that these devices are connected directly to the servers, and then it’s the servers that are connecting off to the network at these higher speeds.  It turns out that the storage devices are not really using networked ports in the Cloud, almost at all.

So that’s a very different architecture to the architecture we saw in the Enterprise, and still do see in the Enterprise.  In the Enterprise, typically, the external storage is connected using Fibre Channel, as Alan was mentioning, at 8 Gbps and 16 Gbps Fibre Channel speeds, as well as Ethernet which are at 1 Gbps and 10 Gbps speeds; and there we are seeing convergence along the lines of what Alan was talking about.  So, we have really two different architectures.

Now, here’s what’s interesting, the architecture for storage that’s being used in the Cloud is in the early stages of migrating back to the Enterprises.  It’s some cool new technology that we see in the Cloud, and it’s working its way back to the Enterprise.  And so there are start-ups now that are making systems that are of that Cloud architecture, and these are working their way back to the Enterprise.

Alan Weckel

Posted by Alan Weckel on July 1, 2015

About Alan

Alan Weckel is Vice President of Enterprise Telephony and Ethernet Switch market research at Dell’Oro Group. He joined Dell’Oro Group in early 2006 and is also in charge of the firm's Enterprise and Data Center coverage areas.