Store and Forward

AT-GS900/8POE Gigabit Ethernet Switch Installation Guide

end node can receive or transmit data, but not both simultaneously, the end node is operating in what is referred to as half-duplex mode. If an end node can both receive and transmit data simultaneously, the end node is said to be operating in full-duplex mode. Naturally, an end node capable of operating in full-duplex can handle data much faster than an end node that can only operate in half-duplex mode.

The twisted pair ports on the AT-GS900/8POE Gigabit Ethernet switch switch can operate in either half-or full-duplex mode. They are IEEE 802.3u-compliant and use Auto-Negotiation to set the duplex mode setting for you automatically.

For Auto-Negotiation to operate properly on a switch, the end nodes connected to the switch should also use Auto-Negotiation. If an end node does not have this feature and has a fixed duplex mode of full-duplex, the result will be a duplex mode mismatch between the end node and a switch port. A port on the Gigabit Ethernet switch connected to an end node with

afixed duplex mode of full-duplex will operate at only half-duplex. This results in the end node using full-duplex and the switch port using half- duplex. This can produce network performance problems. If you encounter this situation, you must configure the port on the end node to use Auto- Negotiation or, if it lacks that feature, to half-duplex.

Note

Because the ports on the AT-GS900/8POE Gigabit Ethernet switch operate in Auto-Negotiate mode only, the end nodes connected to the switch must also be configured to operate in the Auto-Negotiate mode. If an end node is configured to a specific duplex setting in a manual mode, it will not respond to the Auto-Negotiate protocol from the AT-GS900/8POE Gigabit Ethernet switch. (The speed is determined from the link pulses, however, so the speed is always detected correctly.) As a result, the port setting on the switch will end up at half-duplex. If the end node is manually configured to full- duplex, there will be a duplex mismatch and data will be lost. If the end node is manually configured to half-duplex, both ports will have the speed and duplex match up correctly.

The AT-GS900/8POE Gigabit Ethernet switch uses store and forward as the method for receiving and transmitting frames. When a Ethernet frame is received on a switch port, the switch does not retransmit the frame out the destination port until it has received the entire frame and stored the frame in a port buffer. It then examines the frame to determine if it is a valid frame. Invalid frames, such as fragments or runts, are discarded by the switch. This insures that only valid frames are transmitted out the switch ports and that damaged frames are not propagated on your network.

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.