Frame Reception

In essence, the frame reception is the same in both operations of half duplex and full duplex, except that full-duplex operation uses two buffers to transmit and receive the frame independently. The receiving node always “listens” if there is traffic running over the medium when it is not receiving a frame. When a frame destined for the target device comes, the receiver of the target device begins receiving the bit stream, and looks for the PRE (Preamble) pattern and Start-of- Frame Delimiter (SFD) that indicates the next bit is the starting point of the MAC frame until all bit of the frame is received.

For a received frame, the MAC will check:

1.If it is less than one slotTime in length, i.e. short packet, and if yes, it will be discarded by MAC because, by definition, the valid frame must be longer than the slotTime. If the length of the frame is less than one slotTime, there may be a collision happened somewhere or an interface malfunctioned in the LAN. When detecting the case, the MAC drops the packet and goes back to the ready state.

2.The DA of received frame should match the physical address of the receiving MAC or the address of the to be recognized designated multicast. If not, the frame will be discarded and the MAC will pass the frame to its client and go back to ready state.

3.If the frame is too long; if yes, the frame will be thrown away and a Too Long frame will be reported.

4.please note that this kind of sentence is fragment and not grammatically correct. If not, for 10M and 100M Ethernet, discards the frame. For Gigabit Ethernet or higher speed Ethernet, MAC has to check one more field, i.e. extra bit field, to see if FCS is invalid. to see if FCS is invalid.To meet the specification of IEEE 802.3, the MAC will check to see if there any extra bits exist. When both FCS and extra bits are valid, the received frame will be accepted; otherwise the received frame will be discarded and a frameCheckError will be reported if no extra bit appended, or an alignmentError will be reported if extra bits appended.

5.If the length/type is valid; if not, the packet will be discarded and a lengthError will be reported.

6.If all above five procedures are processed without any error, the MAC will treat the frame as a good one and start to disassemble the frame.

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Edimax Technology ES-5240G+ user manual
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ES-5240G+ specifications

Edimax Technology ES-5240G+ is a highly versatile and efficient Ethernet switch designed to cater to the networking needs of small to medium-sized businesses and home offices. With its robust features and reliable performance, this switch is an essential component for a seamless network infrastructure.

One of the standout features of the ES-5240G+ is its 24 10/100/1000Mbps Gigabit Ethernet ports. This allows for high-speed connectivity, enabling users to transfer large files quickly and efficiently. The switch is equipped with a non-blocking architecture, ensuring that all ports can be utilized simultaneously without any reduction in bandwidth. This is particularly beneficial for businesses that rely on high-speed internet and internal networks for their daily operations.

The ES-5240G+ supports advanced Layer 2 switching features, including VLAN (Virtual Local Area Network) support, port mirroring, and link aggregation. These features enhance network management and optimization, making it easier to segment network traffic and improve security. With VLAN support, users can create separate networks within the same switch, leading to improved performance and reduced broadcast traffic.

Moreover, the ES-5240G+ incorporates IEEE 802.3x Flow Control, which helps to prevent data loss during heavy traffic periods. This technology allows for effective communication between devices and ensures smooth data transmission, even in congested network environments. Additionally, the switch is equipped with Automatic MDI/MDI-X detection, eliminating the need for crossover cables and simplifying installation.

From a security perspective, Edimax has included features such as address filtering and port security, which help to protect the network from unauthorized access. The switch can restrict access to specific MAC addresses, providing an added layer of security for sensitive data.

In terms of energy efficiency, the ES-5240G+ is designed to comply with IEEE 802.3az Energy Efficient Ethernet standards. This technology helps to reduce power consumption during low-traffic periods, making it an eco-friendly choice for businesses looking to minimize their carbon footprint.

Overall, Edimax Technology ES-5240G+ stands out as a reliable and efficient Ethernet switch, equipped with a range of features that enhance network performance and security. Its capabilities make it an ideal choice for businesses seeking to streamline their networking infrastructure and improve operational efficiency.
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