Tag Archives: 24 port switch

Understanding Power Consumption of PoE Ethernet Switch

As PoE changes to meet today’s increasing application requirements like IP cameras or WiFi access points, it’s widely used for enterprises networks. Using a PoE or PoE+ switch, technicians can simplify the cabling installation because the PoE technology can support power and data transmission over the same cables. When choosing a PoE Ethernet switch, we always care about the ports and power consumption most. This article will introduce the power consumption of PoE Ethernet switch and take two PoE Ethernet switches as examples to explain power consumption.

What Is Power Consumption of PoE Ethernet Switch?

At present, PoE power consumption follows two standards, IEEE 802.3af and 802.3at. The original IEEE 802.3af rules that power consumption on each port of a PoE network switch can be up to 15.4W. The updated IEEE 802.3at standard also named PoE+, which is backward-compatible with IEEE 802.3af, provides up to 25.5W of power on each port. However, because the power dissipate exists in cables, the minimum output power assured on each port for PoE switch is 12.95W, and 25.5W for PoE+ switch.

power consumption standard

Figure 1: IEEE 802.3af and IEEE 802.3at standards.

The key to successful PoE installation is to ensure that the selected power over Ethernet switch provides the necessary watts of PoE required for each device, and the total power consumption also must be guaranteed for powering all devices. Simply put, the total power consumption of all the connected devices must be controlled in the range of the PoE switch max power consumption.

How Many Devices Can I Connect to My PoE Ethernet Switches?

Power consumption of 150W and 400W are the most popular choices on the market. The following are two switches from FS, 8 port PoE switch and 24 port PoE switch, and we’ll use them to further explain the question how many devices can we connect to my PoE Ethernet switches.

PoE Ethernet switches applications

Figure 2: How many devices can be connected to a PoE switch?

How Many Devices Can the 8 Port PoE Switch Connect?

FS S1150-8T2F switch is a managed PoE+ switch. It has 8 10/100/1000Base-T RJ45 ports, and 2 Gigabit SFP slots. Its PoE standard complies with IEEE802.3af/at. And designed with a max power consumption of 150W, each port can support up to 30W power. This means the switch provides the availability of PoE on all 8 RJ45 ports, and each port can potentially power devices that are connected. From the above, we know the standard PoE can supply 15.4W power for each port, and 30W for PoE+. Therefore, this switch can simultaneously connect 8(15.4W×8=123.2W<150W) devices that use IEEE 802.3af standard, and only 5(30W×5=150W) devices that use IEEE 802.3at standard. For example, if a typical outdoor IP camera needs a PoE power of 20W, the connection of 7 typical IP cameras will require 140W of PoE power (7×20W), which is well within the power consumption of this network switch.

How Many Devices Can the 24 Port PoE Switch Connect?

FS S1400-24T4F managed PoE+ switch is designed with 24 Gigabit PoE+ ports, 1 console port and 4 Gigabit SFP ports. This switch complies with IEEE 802.3af/at with a max power consumption of 400W and 30W for each port. Through a calculation, we know the 24 port switch can connect 24(15.4W×24=369.6W<400W) devices with PoE standard at the same time, and support 13(30W×13=390W<400W) devices with PoE+ standard. And as for the same outdoor IP camera with a power requirement of 20W, the 24 port switch can support 20(20×20W=400W) cameras.

Conclusion

Knowing the power consumption of PoE Ethernet switches is very important. If you want to connect multiple devices to a PoE switch, you need to calculate the total power consumption that all the devices require, and make sure you PoE switch can provide the needed current.

Ethernet Switches: to Stack or Not to Stack?

Over past years, stacking has escalated from a premium feature to a core constituent of an Ethernet switch. Stack switch has become more and more popular among users. When it comes to network design, you may often face two challenges: maximizing scalability and optimizing performance. Finding the right balance can be tricky. This is why you’ve considered stacking or not stacking when managing your Ethernet switches.

What Is Switch Stacking or Stack Switch?

Stack switch is a type of switch designed to be stacked on top of one another. Stackable Ethernet switch is now well established as a stable, standards-based connectivity technology to efficiently handle and manage bandwidth-hungry applications. Stacking allows you to manage multiple switches as a single entity and provides increased bandwidth between the switches. Stack switches can be placed in networking closets and stand alone as a whole unit. The feature sets of stack switch vary depending on vendor and platform. Most stack switches support advanced functions like QoS, multicasting, and VLAN management. For instance, the following FS S3800-24T4S stack switch gigabit is a 24-Port 10/100/1000BASE-T Gigabit switch with QoS flow control and IP subnet-based VLAN. It supports up to 4 switches stacking and up to 96 Gigabit ports and 8 10G SFP+ ports per physical stack, providing up to 512Gbps total switching capacity for the network.

stack switch

To Stack or Not to Stack – Think Twice Before Buying

Whether an enterprise outfits its wiring closets with stack switch or not will depend on what services are needed and how much redundancy is required at the network edge. Stacking multiple switches allows for efficiency and ease of management when you do it right. The switch capacity of a stack is the total port density of the combined switches that are stacked together. For example, when you stack four 24-port switches, you will get one large 96-port switch when it comes to configuration. All these switches in the stack share a single IP address for remote administration instead of each stack unit having its own IP address.

In a small business where access to data and resources are critical, it is a wise option to choose stackable switches because they can significantly reduce downtime and make your network more resilient. In mission critical networks, if a switch within the stack went down, another switch would take over, ensuring that your network remains up and running uninterruptedly. In this way, stackable switches provide additional protection and redundancy for your network. Moreover, you can replace the breakdown switch in the stack without having your network offline for extended periods and impacting employee productivity in the process.

Approaches to Stack Ethernet Switches

Generally, there are mainly two ways to stack multiple network switches into a group. For stack switch with dedicated stacking ports, a stack cable is used to realize switch stacking among them. But only approved cable can be used as stack cable, or else it would cause damage to the switches. The other approach is to use the uplink ports on the switch to connect each switch together in the stacking system. Most stack switches on the market today can be stacked using several types of Ethernet ports including 10GBASE-T copper port, 10G SFP+ fiber port and 40G QSFP+ port as an uplink. For example, FS S3800-24F4S gigabit ethernet switch uses 4 10G SFP+ ports as uplink ports to stack between switches. Up to four of the same type of models can be stacked together via SFP+ transceivers (with fiber patch cable) or DAC cables. Here’s the video to show you how to stack FS S3800 series switches step by step.

FS.COM Stackable Managed Switch List

Model Switch Class Switching Capacity Gigabit RJ45 Ports SFP Ports SFP+ Ports Combo Ports Price
S3800-24T4S Layer2+ 128Gbps 24 N/A 4 N/A US$369
S3800-24F4S Layer2+ 128Gbps N/A 20 4 4 US$389
S5900-24S Layer3 480Gbps N/A N/A 24 N/A US$1999

Note: Please be careful about Ethernet switches in the market which are sold as “stackable” when they merely offer a single user interface, or central management interface, for getting to each individual switch unit. This approach is not stackable, but really “clustering”. You still have to configure every feature such as ACLs, QoS, Port mirroring, etc, individually on each switch.

Conclusion

As your business grows, is your network prepared to grow accordingly? Stack switches have become extremely popular for good reasons. They can simplify management and enhance switching capacity for easy network expansion. But for most customers, achieving super high availability may not be the goal. Then standalone switches are already enough for you rather than stack switches. Thus the pay-as-you-grow stack switch model is suitable for those who need flexibility, not only in their physical network, but also in the amount of traffic that is going through it.

Related Article: FS S5900-24S Stackable Switch: Affordable Option for Network Expansion