The DFE-550FX is an IEEE 802.3u-compliant 100Mbps Fast Ethernet PCI-Bus adapter. MAC controller of DFE-550FX is DL10050A, D-Link in-house design, implementing all advanced network features, including ACPI, IEEE 802.3x Flow-control and IEEE 802.1p prioritization.
Utilizing the plug-and-play features, the DFE-550FX adapter is fully auto-configurable for easy installation. With one built-in SC connector operating at 1300nm-wavelength , DFE-550FX can double the network speed to 200Mbps with distance up to 2000m in full-duplex mode, or 100Mbps network through with distance up to 412m in half-duplex mode. With PCI 32-bit data bus, DFE-550FX can deliver high throughput without the need of the on-board memory because its MAC controller has sufficient built-in FIFO memory for receive/transmit packet buffering. Along with PCI bus master architecture, DFE-550FX can lower the utilization of PCI bus and free the CPU for other bus intensive applications.
ACPI (Advanced Configuration and Power Interface) is an industry specification for the efficient handling of power consumption in desktop and mobile computers. ACPI specifies how a computer's BIOS, operating system, and peripherals communicate with each other about power usage. With ACPI, the operating system can reduce motherboard and peripheral device power needs by not activating devices until they are needed. DFE-550FX complies with ACPI standard, it offering the power management functions for saving power consumption while this NIC is not in full-working.
IEEE802.3x Flow Control
DFE-550FX provides a new feature -- IEEE802.3x full-duplex flow control , this feature needed to function with a switch. When a switch which communicates with DFE-550FX under full duplex mode and it senses that its buffer will overflow in the very near future, this switch will transmits one standard Ethernet packet which indicates DFE-550FX to pause a period for avoiding buffer overflow and packet loss. This mechanism can help switch and NIC to avoid some congestion trouble in advance.
In today's growing network applications, local area networks (LAN) must respond with delivering various types of data. Email, file transfers, database queries, voice over IP (VoIP), video-conference and multimedia delivered at best-effort speeds often with results of slowing down responses to time-critical requests. During the peak hours, network traffic bursts can result in productivity losses and slow network response by non-critical traffic.
IEEE802.1p function allows a range of Ethernet packets prioritized from critical to non-critical through a priority tag. With this priority tagging. The higher priority, time-critical traffic can be preferential treatment and other traffic is running at best effort.
IEEE802.1Q/VLAN function help IT to improve the network performance and security by segmenting network to different virtual LAN. Unlike standard switching, IT can restrict the dissemination of broadcast as well as node-to-node traffic, so the burden of extraneous traffic is reduced throughout the network. Security can be improved also.