Filter
Top Products
Configuring Gigabit Ethernet Parameters
Understanding the Gigabit Ethernet Parameters
Chapter 2
13
*When autonegotiation is on, 1000Base-T will autonegotiate with its link partner;
then, if its partner also autonegotiates and can attain a speed of 1000 Mbps,
1000Base-T will operate at 1000 Mpbs full-duplex (it is not designed to operate at
1000 Mbps half-duplex).
NOTE Partners on a link must be configured to have the same setting, that is, either both
must autonegotiate or both must be set to the same manual setting. For example, if
the card is set to 100 Mbps full-duplex, the link partner must also be set to 100 Mbps
full-duplex. This will help ensure operation without degraded performance.
• Receive flow control
Flow control allows use of flow control negotiation and sending and receiving of
pause frames. When the flow control parameter is on, the card receives and manages
pause frames sent by the link partner. When the flow control parameter is off, the
card will silently discard these pause frames. The card cannot be configured to send
pause frames.
Performance Tuning Parameters
• Send Buffer Coalescing Threshold
• Receive Buffer Coalescing Threshold
• Send Interrupt Coalescing Ticks
• Receive Interrupt Coalescing Ticks
CAUTION These features are for advanced users. If you set these parameters and you do not
understand what they do, you may have unpredictable results. It is recommended to use
the default settings.
When the card transmits or receives a frame, the system must be notified of the event. If
the card interrupts the system for each transmitted and received frame, the result is a
high degree of processor overhead. To prevent that, Gigabit Ethernet provides a feature
called Interrupt Coalescence. Effective use of this feature can reduce system overhead
and improve performance.
Interrupt Coalescence essentially means that the card interrupts the system after
sending or receiving a few frames. The number of frames after which the card interrupts
the processor can be tuned independently for both send and receive. The tuning can be
specified via two parameters each for send and receive, so that there are four parameters
Speed Duplexity Autonegotiation
10 Half Off
10 Full Off
100 Half Off
100 Full Off
1000* N/A* On