Motorola CAJUN P880 - Manual (Page 49)

Cajun P880 Routing Switch Installation Guide 2 - 15
Flow Control
Mode Determines if flow control is used on this port.
For half-duplex links, active backpressure jams
the sending Ethernet channel until the port’s
buffers can receive more packets. This prevents
lost or dropped packets.
For full-duplex links, IEEE 802.3z pause
control allows the port to stop a sending station
from sending more packets if the receiving
port’s buffers are full.
For TX and FX ports, there is an additional
option for Enable with Aggressive Backoff. This
option limits the size of the bursts.
Flow Control is recommended for use
primarily on end-station connections. Using
this flow control on trunk ports can cause
unnecessary congestion on the network.
Auto
Negotiation
Mode Allows you to set the port to auto-negotiate a
speed and duplex mode. Auto-negotiate works
best when the connection on the other end of
the link is set to auto-negotiate as well. If you
set a port to auto-negotiate, and the
connection is not successful, set the port speed
and duplex mode manually.
Auto
Negotiation
Speed/Duplex
Advertisement Determines what information the port
advertises when it starts auto-negotiating. In
most cases,
10/100 and Half/Full are the best
settings, but there may be cases when you
want to auto-negotiate one parameter, while
keeping the other fixed.
Rate Limit
Mode Prevents the switch from overwhelming the
output buffer on lower-speed ports by placing a
threshold on the percentage of port traffic that
can be flooded packets (unknown unicasts and
multicasts). You can optionally include known
multicast packets in this percentage to further
decrease the possibility of the port’s output
buffer being overwhelmed.
Rate Limit Rate Determines the percentage of a port’s
forwarded traffic that can be unknown unicast
and multicast (flooded). Lower this value if the
port has overflow problems.
Table 10. Fast Ethernet (10/100) Port Parameters
Parameter Definition