3Com 10014299 manual Queue-percentage, Dequeue-percentage

266CHAPTER 17: CONFIGURING FRAME RELAY

Configure Frame Relay There are two ways to set the congestion threshold. One is to configure the Congestion congestion threshold for a PVC in a specified Frame Relay class, another is to

Management 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.

1Configure 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	Command
Enable a Frame Relay interface to discard the	fr congestion-threshold de
packets that are marked with DE flag bit in the	queue-percentage
case of congestion
Disable the Frame Relay interface to discard the	undo fr congestion-threshold
packets that are marked with DE flag bit in the	de
case of congestion
Enable a Frame Relay interface to process the	fr congestion-threshold ecn
BECN and FECN flag bits in the case of congestion	queue-percentage
Disable the Frame Relay interface to process the	undo fr congestion-threshold
BECN and FECN flag bits in the case of congestion	ecn

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.

2Configure 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	Command
Enable a Frame Relay PVC to discard the packets	congestion-threshold
that are marked with DE flag bit in the case of	dequeue-percentage
congestion
Disable the Frame Relay PVC to discard the packets	undo congestion-threshold de
that are marked with DE flag bit in the case of
congestion
Enable the Frame Relay PVC to process the BECN	congestion-threshold ecn
and FECN bits in the case of congestion	queue-percentage
Disable the Frame Relay PVC to process the BECN	undo congestion-threshold ecn
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.