3Com 3032 Configuration Manual page 270

266 C 17: C
HAPTER ONFIGURING
Configure Frame Relay
Congestion
Management
F R
RAME ELAY
There are two ways to set the congestion threshold. One is to configure the
congestion threshold for a PVC in a specified Frame Relay class, another is to
configure the congestion threshold for the overall interface in interface view. The
router determines whether there is congestion on the interface according to the
ratio that the current queue length on the Frame Relay interface or PVC occupies
the total queue length on the interface. If the ratio is greater than the threshold
set by the user, the router will assume that there is congestion, and will process
the packets with the corresponding methods, such as discarding.
Frame Relay congestion management include the congestion management on the
Frame Relay interface and the congestion management on the Frame Relay PVC.
1 Configure the congestion management policy on a Frame Relay interface
Perform the following configurations in synchronous serial interface view.
Table 305 Configure the congestion management policy on a Frame Relay interface
Operation
Enable a Frame Relay interface to discard the
packets that are marked with DE flag bit in the
case of congestion
Disable the Frame Relay interface to discard the
packets that are marked with DE flag bit in the
case of congestion
Enable a Frame Relay interface to process the
BECN and FECN flag bits in the case of congestion
Disable the Frame Relay interface to process the
BECN and FECN flag bits in the case of congestion
By default, the congestion management is not enabled on a Frame Relay interface.
When the congestion management is enabled on a Frame Relay interface, the
queueing type on the interface can only be either FIFO or PIPQ.
2 Configure the congestion management policy on Frame Relay PVC
Perform the following configurations in frame relay class view.
Table 306 Configure the congestion management policy on a Frame Relay PVC
Operation
Enable a Frame Relay PVC to discard the packets
that are marked with DE flag bit in the case of
congestion
Disable the Frame Relay PVC to discard the packets
that are marked with DE flag bit in the case of
congestion
Enable the Frame Relay PVC to process the BECN
and FECN bits in the case of congestion
Disable the Frame Relay PVC to process the BECN
and FECN bits in the case of congestion
By default, the congestion management is not enabled on Frame Relay PVCs.
When the congestion management is enabled on a Frame Relay PVC, the
queueing type on the PVC can only be FIFO.
Only when the Frame Relay traffic shaping is enabled on the interface where a
PVC is located, can the congestion management take effect on the PVC.
Command
fr congestion-threshold de
queue-percentage
undo fr congestion-threshold
de
fr congestion-threshold ecn
queue-percentage
undo fr congestion-threshold
ecn
Command
congestion-threshold
dequeue-percentage
undo congestion-threshold de
congestion-threshold ecn
queue-percentage
undo congestion-threshold ecn