There are many questions we field every day here at NetworkTigers. Here, in the second part of two articles regarding what you should ask, as switching experts, we answer five more of the most burning questions people need to consider when considering buying a switch…
Networks are the backbone of every company, and key to network success is choosing the correct switch. But how do you choose the right switch when there are so many on the market?
Here is part two of a quick checklist you can use to help you navigate this complex market and decide which switch to buy. You can find the first part here.
What activities will end users be doing when accessing the network?
Imagine multiple traffic lanes lead up to a bridge. The amount of cars that move across the bridge depends on the car’s speed as well as the number of lanes on the bridge.
Similarly, the number of data packets that can be forwarded depends on the device’s packets per second (PPS) rate and the backplane bandwidth.
High performance switches allow you to connect multiple users with high data needs without any downtime. The data usage of your enterprise is a major factor you need to consider while deciding on which switch to purchase.
The amount of data that can be handled by a particular switch depends on its backplane bandwidth. This refers to the maximum amount of data that can be exchanged between a switch interface processor and a data bus. The total data transfer capacity of the switch is measured in Gbps. A higher bandwidth corresponds to a better capability to process larger data packets.
Bandwidth = Number of ports * Rate of the port * 2 (full-duplex mode).
The forwarding speed is calculated based on the number of packets of data that can be sent by the switch per second. The minimum size Ethernet packets are generally 64 bytes.
The packet forwarding rate of a 100Mbit/s interface is 1.488 Mpps.
Therefore, for a 24 gig port, you will need a speed of 24*1.488=65.4 Mpps
Where will you be installing the switch?
Outside? Inside a data cabinet? Inside the tech closet?
For care and nurturing of your switches, please consider an air conditioned, climate controlled environment, with a cold side of dust-cleaned air entering one side of the switch and warmer air coming out of the other side – and then removed from the room.
Unless you want to ensure a short life for your purchase, do not put your switch in a non-ventilated, dusty, hot, and humid area of your office.
If that is all you have, then the best way not to engage in pre-meditated switch murder is to get a fan and figure a way to put ventilation into the hot area. Then you should plan to have spares.
We have seen switches come back from near-ocean locations covered on the inside with salt dust as that is what is in the air. Plan intelligently for your location.
What types and quantity of ports will you need?
You can calculate the number of switch ports needed by your enterprise by recognizing the number of devices that need to be directly connected by cables on your LAN. Make sure you add at least 10 percent to your current port count to accommodate future needs. Very important to plan your purchase so that you do not have a single-point-of-failure.
If you have one switch and everyone is on it, at some point in the future, that switch will fail. If Murphy’s law holds true, it will fail at the worst possible moment. Best to prepare in advance for that time.
Common ports that are supported by modern enterprise switches include:
- 1 Gigabit Ethernet (1GB), 10GB, 40GB and 100GB ports. They can be a combination of RJ45 ports and SFP/QSFP/CFP uplink ports. RJ45 ports are copper based. Currently, copper connections are either 1GB or 10GB. These ports are less money per port.
- SFP/SFP+/QSFP/CFP are ports which have higher speeds and are 1GB/10GB/40GB/100GB speeds respectively.
What you already have at your office should determine what you buy. If you have a Cat6 or Cat6a cabling system installed in your corporate office, then copper is the way to go.
With fiber uplink ports, these are generally determined by what speeds you are being offered for internet access. Higher speeds would mean more powerful uplink connections. Most businesses generally do well with a 10GB uplink.
What port speed are you considering?
Switches do not produce speed in a network but they can certainly slow it down. For a high demand business, you may need 10GB to the desktop.
For most normal businesses, 1GB to the desktop may suffice. Buying 1GB for a 10GB business could kill the business. Putting 10GB to the desktop for a non-data intensive business would be overkill.
If you have a company of power users, you will need ports that will raise your budget to get to 10GB per port.
Will you be stacking the switches?
Ten years ago, you could walk into any mid-size business data center and see several large 200lb chassis in cabinets with full on air conditioners that would cool a town. Those chassis were expensive to buy and expensive to maintain and operate. The OEMs morphed this “chassis” to the stacked switch option.
Rather than planning a data center around a chassis, one can now buy a switch and add it to the stack of switches to expand a network. Expanding a network can be easy and one does not need to pay the electric company a fortune to cool the stack.
When stacked together, these stackable switches become virtually one switch. This simplifies operational and management tasks by integrating it into a single interface.
It also provides better bandwidth and reduces the complexity of network design architecture. You can also merge ports with different speeds, capabilities and models which increases the flexibility of your network.
When do you need the switches delivered?
The pandemic has disrupted the global supply chain. Without the continuous flow of new switches into the market, used switches have been bid up in value and some are very hard to find.
Some switches that you may be used to finding everywhere, may be expensive now and hard to find. Others will take longer to deliver than the others. Please ask your supplier before making a decision.
For all these options or to get help in working out what you would need, visit NetworkTigers for all your switch needs – and with overnight shipping until 5pm PT.