Top of rack switching in a nutshell
Top of rack switching, often abbreviated as ToR, is a popular methodology for data center management and an alternative to end of row switching, or EoR. In a top of rack system, each server is connected to a switch mounted within the same cabinet making for a self contained arrangement. This switch is then connected to an external central aggregate switch. End of row switching, alternatively, requires each individual server to connect to the central aggregate switch directly. The servers in an end of rack switching scenario may be spread across different cabinets.
Advantages of top of rack switching
As the sheer density of servers per rack has skyrocketed over the past decade, both due to increased network data requirements as well as a general decrease in the size of the equipment, top of rack architecture is often the more appealing manner in which to arrange and build data centers. With the advantages offered by this method as opposed to end of row architecture, it’s no surprise to see why this is often the go-to solution for data centers the world over.
1. Less clutter
Top of rack architecture is a dream come true for those who wish to avoid the clutter and madness so often associated with data rooms as all of the servers in each cabinet are first connected to the switch located internally within the same rack. As a result, fewer cables run between the cabinets and the aggregate switch. A lower cable requirement also has the added benefit of being less expensive as it does not require the same extensive infrastructure of copper cabling running throughout the data center. The days of dozens of yards of cobwebbed, dusty cable runs could be put in the rearview mirror with the implementation of top of rack switching.
2. Flexibility in placement
As an added bonus, the “top” part of the term “top of rack” is not a hard and fast rule. While it generally holds true that people prefer the ease of access granted by mounting the switch around eye level, one can instead install the switch in the middle of their cabinet between their servers. This allows them to standardize cable lengths to more similar measurements as opposed to a bevy of extremely long and short runs. Cables of close lengths provide a tighter, more efficient environment yielding yet another often overlooked advantage made possible with top of rack switching architecture’s cable efficiency: there are fewer ventilation obstructions and restrictions when it comes to keeping equipment cool. More mess means more heat.
3. Easy to rearrange
Top of rack switching arrangements are more modular than the alternative. Having everything you need in one cabinet means you can deploy more easily and in less time. Cabinets can be moved relatively easily with only minor disconnections and inconvenience due, once again, to the minimized external cabling. Data centers can be rearranged to accommodate changes in the room layout as needed without the need for a tremendously time consuming overhaul.
4. Efficient troubleshooting
This modular characteristic makes it easier to diagnose, isolate, and remedy technical issues as well. In an end of row system, a problem could potentially affect an entire row of server cabinets and the source of said issue could be challenging to track down as a result. As opposed to a problem harming a significant portion of your data center, the previously mentioned modular nature of top of rack switching means if something goes wrong it will typically only affect the servers placed within that cabinet. This makes for a much less advanced game of troubleshooting whack-a-mole.
5. More futureproof
Additionally, upgrading a top of rack system is a more streamlined process than in the alternative. Parts can be swapped out and replaced with only a very slim possibility of a change having unexpected consequences outside of the specific cabinet that you’re working on. This makes top of rack architecture ideal for those who prioritize a more future proof data center in the ever changing world of IT.
In summary
While there is no one size fits all solution to improve the efficiency of the world’s data centers and no universally suitable layout for every situation, for those who are seeking an arrangement that allows for supreme efficiency, top of rack architecture could be a no brainer, especially for new builds. While it is true that adherents to end of row methodology will make note of the fact that more switches means more potential management costs and the modular nature of top of rack systems may require some rack spaces to go unfilled, these small trade-offs pale in comparison to the overall logistical advantages and potential financial savings associated with having a top of rack switching system in place.
Top of rack switching allows for:
- Significantly reduced cable complexity
- A greater possibility for lower overall cost
- A modular design that facilitates movement and deployability
- Far less clutter resulting in improved airflow
- Easier troubleshooting and upgrading due to cabinets behaving independently
