You have a network plan. You know how you’re going to set everything up to make everything work. It’s time to do some purchasing.
Before you fill out your credit card information, take a minute to make sure you’re getting exactly what you need. By asking just six questions, you can avoid purchasing mistakes that limit networking capabilities or send you way over budget.
How Many Ports Do You Need?
This is the natural starting point. What is the purpose of the switch? How many devices will it directly support? Those questions tell you how many ports you need, and when browsing hardware, searching via port capacity is usually the easiest first step.
The majority of professional-grade Cisco switches are going to offer somewhere between 12 and 48 ports per switch, and if you need more than that in a single hub, you can consider stacking capacity, but we’ll talk more about that in a bit.
What Kinds of Speeds Do You Need?
Once you separate your options according to port capacity, it’s time to consider connection speeds. It’s often best to look at the switch’s total throughput first. This will tell you how much data transmission is possible across all of the connected devices, so ensure that you have sufficient capacity for the task at hand.
Once you consider throughput, you also need to compare speeds per port. A 48-port switch can have a lot of throughput, but if half of the ports are only 10/100 Ethernet (this is an unlikely example), then your connected devices are going to struggle. So, think about how much bandwidth the connected devices will really need and make sure each port is sufficient.
Are You Looking for Layer 2 or Layer 3?
Port numbers and speed capacities are the easy part. Now, it’s time to consider where the port will fit within the network. What kind of routing do you need the switch to manage? You can find comparable ports with the same throughput and port numbers that are designed for either Layer 2 or Layer 3 management.
For a quick recap, Layer 2 management administers connections according to MAC addresses. Layer 3 switches can juggle IP addresses. Also remember that Layer 3 switches can handle Layer 2 networking, but the reverse is not true.
Do You Need PoE?
Power over Ethernet is one of the most powerful features in a switch’s arsenal. By powering devices via Ethernet, you can simplify network designs and save tons of money on routing power to each endpoint device.
But, if you don’t need PoE, then you should get switches that don’t support it. After all, PoE capabilities often add to the price of each switch.
If you are using PoE, then you need to think about your power budget. Make sure the PoE capabilities of the switch are sufficient for all of the devices you intend to utilize with that specific switch.
Are You Using SFP or SFP+?
Many professional networks utilize fiber optics to do the heavy lifting and implement switches to connect Ethernet devices at the endpoints. If this is your strategy, then your switches need to be able to interface with your fiber optic systems.
Most commonly, you’ll want SFP or SFP+. Take a few minutes to see what connection types are supported by your existing fiber infrastructure. Then, you can make informed shopping decisions and purchase switches that are already compatible. It’s a few minutes to save a lot of pain.
Do You Need Stacking Capability?
Lastly, you want to compare stacking capacity. For simple networks, single switches might be sufficient, but for large networks (or networks that you expect to grow over time), switching capacity is essential.
You can find two switches that are nearly identical, but if they don’t use the same stacking management, they might have very different stacking capacities. As an example, Cisco makes a few different stacking management tools, and each has its own capacity. StackWise 80 has half the capacity of StackWise 160. You get the idea.
Remember that you don’t have to fill a stack to its capacity right away, so it’s usually better to purchase with room to grow rather than the other way around.
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