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Does Converging the LAN and SAN Make Sense?

November 29, 2011 - 2 Comments

Why exactly would IT organizations want to converge their LAN and SAN?

For years, organizations have been running separate, parallel networks in their datacenter: an Ethernet-based LAN to connect servers, clients, and a storage area network (SAN) to connect servers to the storage pool. Collapsing these networks down to a single common network infrastructure could save capital costs by eliminating redundant switches, cables, networking cards, and adapters.    Customers could immediately realize cost savings by simplifying the network administration.

Organizations can achieve these benefits:

  • Efficiency.  Eliminate   infrastructure redundancy.
  • Agility. Provides the ability to set up, move, and change both physical and virtual servers faster to   easily respond to ever changing business needs.  
  • IT transformation. Enables datacenter consolidation, and supports a capacity demand model that help IT organizations do more with less.

Now let us go back to the question “Does converging the LAN and SAN make Sense? 

As part of The Data Center LAN Evolution Series, Thought Leadership discussion Dr. Jim Metzler, Moderator, Ashton, Metzler & Associates posed the following 3 questions (The discussion was about the viability of converging the LAN and SAN and involved Arista, Avaya, Brocade, Cisco, Extreme and HP) 

1)    What advice can you give to IT organizations that are trying to plan for the possible convergence of the LAN and the SAN in their data center ?

2)    How will end to end LAN/SAN convergence benefit customers? What type of ROI can I expect and are there any tools to justify the savings?

3)    How do you manage and operate an end to end SAN / LAN converged network? 

Cisco took a multi-protocol approach; convergence is not just about FCOE,  it is about converging the end to end infrastructure.  All of the vendors except Arista claimed some sort of savings by implementing convergence.  Arista claims that for many enterprises the number one priority is to enable virtualization and they don’t see convergence as priority.  It is understandable why a vendor without a product portfolio to support end to end convergence   would not see convergence as a priority.

 IDC recently published a paper, “The ROI  of   Converged  Networking  Using Unified”  that stated that businesses with fully converged networks can achieve an ROI of up to 492% with an 11 month payback and a 45% CapEx saving. Cisco also provided a TCO tool which is based on the IDC research. 

HP suggested that IT organizations should carefully characterize  ” SAN/LAN consolidation and simplification opportunities as they consider   FCoE, NAS, DAS and iSCSI technologies . All are  potentially viable approaches. HP further recommended that IT organizations start at the server edge   when considering FCoE, and that customers   should look first to server vendors who have complete integrated solutions. 

To read the full discussion online:  or you can download a PDF version or summary by Jim.

Conclusion:  Do not take Cisco’s word for it. Independent analysts have confirmed via white papers that cost savings do exist when converging  LAN and SAN infrastructures!!!  Take a look at the End to End TCO calculator to see how much cost savings you can realize by converging your network.

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  1. Good point. Yes we need to remove the organizational barriers in order for transparent technology convergence. Good news is, most of the CIO’s are now onboard with the concept of Organizational Convergence in order to gain efficiency with IT/Technology convergence.

    Here is a third party paper on Removing organizational barriers for leveraging technology convergence ( )

    Also this is not just theoretical calculations – take a look at the long list of customers currently using Cisco technologies to converge. ( )

  2. What most vendors tend to overlook is that the technology is not the problem. The organization and culture is.. Most companies still work in seperate silo’s: storage – servers – network. Unifying the network seems cheaper on paper but you have to deal with something a simple networkmigration can’t replace overnight and that’s the culture change with each and everyone in the organization. It is logical the Cisco’s and HP’s of this world don’t deal with this kind of change, but for CTO’s its a very important factor in driving convergence. On the operations side and all the processes (e.g. ITIL and what have-you) accompanying this you have to make a far more fundamental change than pushing new technology.

    I challenge all vendors to forward this in their slideware. I do not expect them to have an answer for this (let the McKinseys deal with this 😉 ), but they should at least be aware of this. More than I see them do now..