Radiance 10/100 Mbps Services Line Card
30
The following table describes when full-duplex flow control is enabled or
disabled. In the table, “Port 1’s Link Partner” is the flow control capability
of the device connected to Port 1. The Link Partner’s capability is
obtained through auto-negotiation. 0 = disabled, 1 = enabled, and X =
not applicable.
Half-Duplex Flow Control
When a port is operating at half duplex, the R821 provides an option to
activate backpressure flow control. If half-duplex flow control is enabled,
the card will generate a jamming pattern to force a collision whenever it
cannot allocate a buffer for the port’s incoming frames.
ICMP
The R821 supports Internet Control Message Protocol (ICMP) to confirm
basic network connectivity. By default, the unit is enabled to respond to
all ping requests. Through software, you can reconfigure the R821 as
follows:
•
Only unicast ICMP messages are processed. The card will not process
ICMP messages sent to IP multicast, IP subnet broadcast, and IP
limited broadcast addresses.
•
All ICMP messages are not processed
•
All ICMP messages are processed
Note:
The ICMP setting cannot be reconfigured at runtime.
Table 4: Full-Duplex Flow Control Modes
Port 1’s
Link Partner
Full-Duplex Flow
Control Settings
Auto-Negotiation
Full-Duplex Flow
Control
X
X
0
Disabled
0
0
1
Disabled
0
1
1
Disabled
1
0
1
Disabled
1
1
1
Enabled
