Top of Rack Networking: Employing Software-Defined Networking for Optimization with Flexibility

- Iain Kenney, Director of Product Marketing at LG Ericsson USA (www.lgericssonus.com), says:

In today’s world, where access to information is king, the ‘palace’ is under constant renovation. Data centers are expanding at a rate beyond what anyone would have predicted while the 21^st century data center makes the “massive server farms” of the information age seem like so much wasted space. Data centers today are optimized to the nth degree and careful planning is critical to ensuring that these massive data centers are protected from potential failures and hazards.

Ensuring that accessibility to the servers and data is as efficient as the floor plan is critical to success; enabling easy adjustments and optimization is paramount. Software-defined networking (SDN) will be key to unlocking the full potential of the next generation 21^st century data center.  SDN facilitates on-the-fly network reconfiguration, and even enables creative server placement for highly-responsive expansion and just-in-time capacity adjustment. Top of Rack (ToR) architecture, set-up and managed via software, sets the stage for responsiveness, efficiency and, ultimately, cost-effectiveness, makes good sense for business.

Evolving for Efficiency

Today’s networks must be built for the ultimate in efficiency; software-defined networking is the key to achieving that efficiency.  Whereas it used to be that servers were organized by specific application or data types or sets, today, due to the amazing volume of data and activity, every bit of processing power and every bit of data on every server in every data center needs to be optimized. Networks have evolved from being composed of small numbers of single-purpose networked servers to large numbers of highly virtualized servers, all of which can share pieces of the same application or data set. 

To accommodate that need for efficiency, the network itself needs to evolve—beyond the networking hardware itself.  Bandwidth and ‘speed’, the buzzwords for efficient networking in the past, don’t cut it any more: networking hardware that has all of the right features to enable speed gets bogged-down by a large, proprietary code base.  That code base overcomes the ‘specs’, slowing the network’s responsiveness and aggravating users.

The Search is On

Now, data that used to reside on a single server in an ‘organized’ fashion can be distributed in an ‘optimized’ form across multiple massively high-performance servers—sometimes all in one physical data center, sometimes across town, sometimes around the globe.  Use of those servers, which are doing lots of things—and lots of parts of things—needs to be optimized and the left hand, so to speak, needs to know what the right hand is doing. And, of course, in addition to use and storage, redundancy and backup need to be managed and tracked, too. With everything so spread out, information location becomes more complex.   Virtualization holds the key.

Word of the Day: Hadoop

Introduced as a standard, then absorbed into the ever-growing collection of trendy tech jargon, Hadoop, quite simply, describes the distributed processing and cross-sharing of application data across servers. Designed as an open standard by the Apache Group, Hadoop helps a server farm full of machines act as one: like a borg, its single consciousness means that killing one will not affect another.  Any server can be a master to or a servant of any other.  This construct makes for the ultimate in efficiency – in storage usage, and in access.

Factoring-in Failure
Servers are cheap, so building a data center that can ensure redundant storage and fail-safe availability is easily accomplished with simple replication. Access is a different story.  The network enables users to access all of that replicated data, so the ToR switches are critical to getting at the data: no matter how many copies of the data are stored, if users can’t access it, it isn’t ‘there.’

In, Across and Between the Racks
Connecting all of those servers through a core networking system gets users to the data and applications they need, re-routes requests when servers go down, and keeps data flowing.  Point-to-point networking doesn’t make sense, because the cabling nightmare to make it all happen would be overwhelming.  Top of Rack networking facilitates access across racks and racks of servers, often each with 50 or more servers running 10 or more virtual machines—500 devices— each in a single 72U rack.  Keeping track of a single rack, let alone a data center full of rows of racks, is a formidable task.  Network switches—ToR switches—are the critical link –that connects everyone to everything.

Network switches don’t fit the server model of cheap redundancy.  Cheap, so-called ‘white-box’ switches can’t be relied upon to shoulder the weight of a mission-critical network, but buying the most expensive isn’t the best alternative, either.  Ironically, high-priced solutions come not just with a higher initial price tag, but also incorporate proprietary solutions that can lock the data center into unintentional allegiance that locks-up the budget.

In today’s high-volume, high-accessibility data center, density is so massive that the cables alone for a traditional point-to-point network would be overwhelming.  ToR networking aggregates access at each rack, connecting all of the servers in the rack to each and every other rack.  Managing the access within and across racks is a challenge accommodated by solid switching solutions: 1G or 10G connections accomplish efficient server-to-server links within the rack; 1G and 10G manage Northbound traffic, rack to core; and connections of up to 40G manage East-West (rack to rack) traffic, in a 2-3 level mesh network.

Putting the Pieces in Place: High-Capacity, High-Performance, High-Availability Switches

Evolution is bringing us to the next generation of network devices.  Those devices will take better advantage of the advanced, high-speed network hardware architecture—and advances to it—by using a slimmer and more open code base that enables data center managers to define and implement new architectures and change the architecture as business needs change. And, it will make it easy to make those changes by utilizing SDN.

Whereas it used to be that server capacity and network bandwidth were the critical factors.  Now, being constrained by inability to make efficient use of the massive capacity and bandwidth that are available, we need more sophisticated solutions for traffic management.  Constant monitoring and on-the-fly adjustment are the way to efficient computing, and that can best be accomplished when data center managers have the tools to expand, contract, and re-configure the data center architecture easily and without waiting for a vendor to act on a tech support or modification request job ticket. 

No one knows what will work best for a given network better than that network’s administrator—and fine-tuning, combined with a little bit of trial and error, often makes good even better.  High-quality, high-capacity, highly-reliable, standards-based, SDN configurable network switches, within, on top of and between racks of servers, are the answer.  SDN provides the potential for a ‘do-it-yourself’ framework with dynamic drag-and-drop configurability that makes the most dynamic, responsive network a reality. Acknowledging the reality of today’s dynamic data center, SDN provides a responsive platform for data center growth and adjustment.  Separating the configuration and programming of ”the network” from the underlying hardware enables managers to avoid vendor lock-in, lower costs and, most importantly, to be more responsive to user needs.

Commodity Plus: LG-Ericsson USA – Solid Hardware and Warranties with SDN
Designed for Dynamic Environments

LG-Ericsson USA brings the best of both worlds to bear for Top of Rack switching in today’s dynamic data center with high-density, ultra-high bandwidth, standards-based ToR switches, backed with great software and firmware, superior warranties and US-based support.  

LG-Ericsson USA’s powerful, high-bandwidth ToR switches keep it all flowing—inside the central office and out to the mobile universe.  The company’s 1G, 10G, 10G + 40G and 40G energy-efficient, rack-mountable, hot-swappable, standards-compliant OpenFlow-ready switches ensure efficient, reliable data centers.  With OpenFlow enabling circuit-switched networks in packet-switched environments for easy software-driven management of data flow, our ToR switches bring simplification, reliability, support and hot-swappable components to software-controlled networks.  And, LG-Ericsson shows our commitment to the customer by bringing all of this functionality, efficiency in an affordable, standards-based, software configurable (SDN) solution.