D-LINK DFE-580TX 4-port PCI 10/ 100Mbps Fast Ethernet Server Adapter

DFE-580TX
4-port PCI Fast Ethernet Server Adapter

4 Port 10/100Mbps
NWay Ethernet & Fast
Ethernet Internal PCI
Server NIC/Adapter
with Port Trunking

Powerful Performance
This 4-port adapter provides very high-speed for servers-to-switch connection. With multiple dedicated bandwidths, load sharing and redundant backup functions built in, this adapter is most suitable for bandwidth-demanding, mission-critical client/server applications.

Bus Master Operation
The adapter operates in the 32-bit bus master mode to deliver throughputs at multi-megabits per second with little stress on the host's CPU. Running at PCI clock speeds of up to 33Mhz independently of the network clock, each of the 4 ports has its independent MAC transferring data directly to/from the host's memory, by-passing the CPU to alleviate the host's workload.

4-Port Trunk
Each of the 4 ports on the adapter can establish an independent full-bandwidth segment with a switch. When all 4 ports are connected to the switch, an 800Mbps trunk (4 Fast Ethernet ports running at full duplex) is created enabling high-speed, simultaneous access by workstations.

Per-port 10/100Mbps, Full/half Duplex Support
All 4 ports independently support IEEE 802.3u auto-negotiation standard, meaning each port individually auto-senses 10/100Mbps network speed and auto-negotiates between 10BASE-T/100BASE-TX connection and full/half duplex. This gives users the maximum flexibility to establish a different line speed and transmission mode for each port.

SNMP Management
On-board SNMP MIB counters allow the administrator to monitor statistics/traffic going through the server and to carry out other management tasks such as security control from a management station running on D-Link's D-View, HP OpenView or other platforms.

Load Balance/Redundant Backup
Users can configure all ports to be active (load-sharing mode) or some ports to act as backups (redundant links). Load sharing balances traffic among the active segments, while backup redundancy provides uninterrupted links between the server and the switch. The adapter comes with configuration software to permit users to configure these and other operation modes.

Features
4 10/100Mbps ports with independent MACs
IEEE 802.3 10BASE-T/802.3u 100BASE-TX standard
PCI local bus 2.1, 2.2 specifications
Full/half duplex per port
32-bit PCI bus master operation
On-board PCI-to-PCI bridge chip
800Mbps server-to-switch trunks
Per-port load-balance/fault-tolerance configuration
Dynamic fail-over function for backup mode
Protocols supported: IP, IPX, NetBEUI
Built-in SNMP MIBs
FCC Class B, CE Mark, VCCI Class B, C-Tick

LAN Drivers
NDIS driver for Microsoft Windows NT 4.0 and 2000

How DFE-580TX Works
One common method used to alleviate server bottlenecks involves segmenting the network across multiple NIC's in the server. Figure 1 illustrates a typical setup utilizing four NIC's to segment the network so that if a failure occurs on one segment, it should not affect the other segments. If one segment fails, access to the server is lost for all clients on the failed segment. To get the clients on the failed segment back online the whole server has to be brought downed. Each segment is also limited to the throughput of a single NIC between the server and the switch or hub. During peak access times, bottlenecks can still occur.

DFE-580TX NIC Design
DFE-580TX takes the segmented server concept one step further to provide for optimal use of all network adapters and guaranteed up time for all users across the network. Instead of assigning one network adapter to each segment, adapters are grouped together and treated as one logical adapter. Network traffic can then be balanced across all of the adapters so that a bottleneck does not occur at each network segment. Also, if any one connection or adapter fails, traffic is rebalanced over the remaining adapters so that all connections to the server are maintained. Figure 2 shows the same network with a single DFE-580TX represented by 4 adapters connecting to 4 segments.

Multi-Segment DFE-580TX
DFE-580TX can allow for segmenting the network at the server level. Figure 3 is an example of an Intranet server for which the network has been divided into two separate segments. Engineering and Accounting are on the first segment and Sales and remote users are on the second segment. Unlike the first example, this design provides for maximum throughput and fault tolerance for each segment. Each segment consists of an array of two network adapters with failover and load balancing being provided within each segment.


DFE-580TX Driver Architecture
DFE-580TX for Windows NT is designed to be easily installed and unintrusive to the operating system. It is designed as an NT Intermediate NDIS driver similar to other network drivers for NT and that it sits on top of existing NIC drivers. The DFE-580TX driver shields the multiple adapters from NT and creates one virtual driver for each network segment installed.

In Figure 4 illustrated below, two network segments are created with each containing an array of two adapters. The DFE-580TX driver borrows the MAC address of the primary card in each array and advertises this single address to the NT Protocols stack. The Protocol Stack sees only one port to the network thus creating a virtual port for the operating system.

The NDIS driver handles all software functions for load balancing and dynamic failover in the NT Kernel. Kernel mode operation insures maximum performance with little to no latency. Also by operating in the kernel mode, DFE-580TX does not affect applications running in user mode thereby making compatibility issues moot.