Power over Ethernet (PoE) is the ability to control devices such as IP phones, IP surveillance cameras, and wireless access points with the same cable as data traffic. One of the advantages of PoE is that its flexibility makes it easy to deploy terminals anywhere in the company. This allows you to place the end point in a place where it is difficult to install an outlet. For example, you can place a wireless access point inside a wall or ceiling.
The switch supplies power in accordance with various standards. IEEE 802.3af provides up to 15.4 watts of power at the switch port, while IEEE 802.3at, also known as POE +, provides up to 30 watts of power at the switch port. 802.3af is sufficient for most terminals, but some devices have higher power requirements, such as video phones and multiple wireless access points. Some Cisco switches also support 60W PoE or UPoE (Universal Power over Ethernet), providing up to 60W of power from the switch ports. The new PoE 802.3bt standard provides a higher level of power for future applications.
To find the correct Network switch, choose the switch based on your power requirements. When connecting to a desktop computer or other type of device that does not require PoE, it is more cost effective to use a regular switch.
Comparison of stacked and autonomous switches
As the network expands, more and more switches are needed so that an increasing number of network devices can connect to the network. If you use independent switches, each switch is managed / configured as a separate entity.
On the other hand, stackable switches provide an easy way to configure your network and increase availability. That said, with stackable switches, you can manage 8 switches as a single unit instead of individually configuring / managing and troubleshooting 8 48-port switches. In a fully stacked switch, 8 switches (384 ports total) act as one switch. So you have an SNMP / RMON agent, spanning tree domain, CLI, or web interface all in one (single management plane). You can create a link aggregation group that includes all devices in the stack, create port mirroring traffic between devices in the stack, or set an ACL / QoS that applies to all devices. There are several operational benefits to using this approach.
However, when choosing a "stacked" product on the market today, you should check the detailed specifications. Some products provide only one user interface (central management interface) that can be used for individual switch devices. This approach can be called "clustering" instead of a stack. That said, with these products, all features like ACL, QoS, and port mirroring must be configured individually on each Network Switch.
There are other advantages to fully stacked switches as well. If a port or cable fails to connect a stack member to the ring, the stack is typically automatically routed within nanoseconds and is not affected by that error. You can also add or subtract members from the stack and then add them to the stack using automatic recognition.
