7-18 Frame Relay Module 4.0 User Guide, Rev 01DLCI ParametersCommitted Information Rate (In/Out)(CIR) is the incoming or outgoing (depending on the parameter) data throughput thatthe network agrees to support under normal conditions. Outgoing throughput greaterthan CIR will be reduced to CIR if (a) a packet is received with the BECN (backwardexplicit congestion notification) bit set, and (b) Enable Outgoing Rate Control is Y.Committed Burst Size (In/Out)(B C ) is incoming or outgoing (depending on the parameter) the maximum amount ofdata that the network agrees to transfer under normal conditions within the time perioddefined by BC /CIR. Any data exceeding B C will have the Discard Eligibility (DE) bitturned on, and will be tracked by the FRM statistic DE/sec (*10).Turning on the DE bit will not automatically cause a packet to be discarded, but willtell the network which packets it can discard if traffic becomes too heavy.Excess Burst Size (In/Out)(B E) is the incoming or outgoing (depending on the parameter) maximum amount ofdata in excess of the Committed Burst Size that the network will attempt to transferduring the time interval used for the Committed Burst Size. Any outgoing dataexceeding this value will be buffered in the FRM, and any incoming data exceedingthe value will be discarded.BECN Recovery Countis a method of controlling the rate of return to maximum traffic flow after it has beenreduced due to congestion. If a packet is received with the BECN (backward explicitcongestion notification) bit set, outgoing traffic will be throttled back to CIR, and theeffective value of B E will become 0 (limting traffic flow to the configured BC ). Fromthat point on, for each "n" packets (where "n" is the value of BECN Recovery Count)received (sequentially) without BECN set, the effective outgoing B E will be increasedby 1/8 of the configured value.As long as no BECNs are received, the effective burst size will continue to increaseuntil it reaches the full configured value. Any time a BECN is received, however, theeffective value will return to the value of the outgoing B C.Outgoing DLCI Prioritysets a priority for this DLCI among others over the physical port. Note that 4 is thehighest priority.Backup Group Numberspecifies (if configured as any number other than 0) that this is a primary DLCI, andidentifies the backup DLCI(s) (see "Configuring Frame Relay Backup Groups" onpage 7-21) that will take over if this DLCI fails. This parameter is applicable only onan "initiating" node, which is the node that will initiate the switchover to a backupDLCI. At switchover, the initiating node notifies the remote node of the change.A DLCI cannot be both a backup and a primary.
