Power over Ethernet

Chapter 1: Overview

The twisted pair ports on the AT-GS900/8POE Gigabit Ethernet switch feature Power over Ethernet (PoE). PoE is a mechanism for supplying power to network devices over the same twisted pair cables used to carry network traffic. This feature can simplify network installation and maintenance by allowing you to use the switch as a central power source for other network devices.

A device that receives its power over an Ethernet cable is called a powered device. Examples of such devices can be wireless access points, IP telephones, web cams, and even other Ethernet switches. An example of the latter is the unmanaged AT-FS705PD Ethernet switch from Allied Telesis. A powered device connected to a port on the switch will receive both network traffic and power over the same twisted pair cable.

There are several advantages that the PoE feature of the AT-GS900/ 8POE Gigabit Ethernet switch adds to the installation and maintenance of your network. First, because the switch acts as the central power source for your powered devices, adding an uninterruptible power source (UPS) to the switch increases the protection not just to the switch itself from possible power source problems but also to all of the powered devices connected to it. This can increase the reliability of your network by minimizing the impact to network operations from a power failure.

PoE can also simplify the installation of your network. A frequent issue in selecting a location for a network device is whether there is a power source nearby. This often limits equipment placement or requires the added cost and time of having additional electrical sources installed. With PoE, you can install PoE-compatible network equipment wherever they are needed without having to worry about whether they are near a power source.

The switch automatically determines whether or not a device connected to a port is a powered device. A powered device has a signature resistor or signature capacitor that the switch can detect over the Ethernet cabling. If the resistor or capacitor is present, the switch assumes that the device is a powered device.

Power Budgeting The AT-GS900/8POE Gigabit Ethernet switch provides a maximum of

15.4W of power per port on four of the eight ports for a total power consumption of 65 W, while at the same time furnishing standard 10/100 Mbps Ethernet functionality.

The AT-GS900/8POE smart power management functionality supports any combination of Ethernet ports (1-8) that supply power for IEEE 802.3af Class 0, 1, 2, or 3 powered devices up to a maximum of 65 watts, as described in Table 5.

GS900/8POE specifications

The Allied Telesis GS900/8POE is a versatile and robust switch designed for small to medium-sized enterprises that require reliable network performance combined with power over Ethernet (PoE) capabilities. As part of the GS900 series, this switch offers a range of features, technologies, and characteristics that cater to modern networking demands.

One of the main features of the GS900/8POE is its eight 10/100/1000BASE-T Ethernet ports, which enable seamless connectivity for a variety of devices. Each port is equipped with Power over Ethernet capabilities, allowing the switch to deliver up to 15.4 watts of power per port. This is particularly beneficial for powering devices such as IP cameras, wireless access points, and VoIP phones without the need for additional power sources, minimizing installation costs and clutter.

The GS900/8POE also supports advanced Layer 2 switching capabilities, including VLAN (Virtual Local Area Network) support, which enhances network segmentation and security. By allowing administrators to create isolated networks within a larger network, VLANs reduce broadcast traffic and improve overall performance. Additionally, the switch supports Quality of Service (QoS) features, ensuring that time-sensitive applications, such as video streaming and voice communications, receive priority over less critical data.

Another noteworthy characteristic of the GS900/8POE is its fanless design, which makes it ideal for environments where noise levels need to be kept to a minimum. This design approach not only enhances the aesthetics of the deployment area but also increases reliability by reducing moving parts that could potentially fail.

Security is also a significant focus in the GS900/8POE's design, with features like MAC address filtering and DHCP snooping to protect against unauthorized access and potential network attacks. These safeguards ensure that network administrators can maintain control over connected devices and mitigate risks associated with security breaches.

In summary, the Allied Telesis GS900/8POE switch is a feature-rich solution that meets the demands of modern networks. Its PoE capabilities, advanced Layer 2 features, fanless operation, and robust security measures make it an excellent choice for businesses looking to expand their network infrastructure while keeping operational efficiency and reliability at the forefront. Whether used in a small office setting or for branch locations, the GS900/8POE provides a compelling balance of performance and functionality.