Dell Force10 S25-01-GE-24V FTOS 8.4.2.7 Configuration Guide for E-Series TeraS - Page 676

www.dell.com | support.dell.com • Allocate More Buffer Memory for Multicast WRED • Allocate More Bandwidth to Multicast using Egress WFQ Allocate More Buffer Memory for Multicast WRED Allocate more buffer memory to multicast WRED (Weighted Random Early Detection) for bursty multicast traffic that might temporarily become oversubscribed. For example, the example WRED profile in Figure 41-14 on page 872 allocates multicast traffic a minimum of 40 megabytes (out of 80 megabytes) of buffer memory and up to 60 megabytes. Figure 30-9. Allocating More Bandwidth for Multicast WRED FTOS(Conf)#queue egress multicast linecard all wred-profile Egress FTOS(conf)#wred-profile Egress FTOS(conf-wred)# threshold min 40960 max 61440 Allocate More Bandwidth to Multicast using Egress WFQ Egress Weighted Fair Queuing (WFQ) determines per port the ratio of egress bandwidth allocated to multicast, replication, and unicast traffic. By default, FTOS provides 1/64 to multicast, 1/64 to replication, and 62/64 for unicast, which is shared between 8 unicast queues. Allocate more bandwidth for multicast using the command queue egress multicast linecard (from CONFIGURATION mode) with the keyword bandwidth-percent. For example, allocate 80% of egress bandwidth to multicast on all line cards using the command queue egress multicast linecard all bandwidth-percent 80. Tune the Central Scheduler for Multicast The Central Scheduler is responsible for scheduling unicast and multicast packets via the Terabit backplane. The default configuration of the Central Scheduler is optimized for network environments that forward primarily unicast traffic-80% of the scheduler weight is for unicast traffic and 20% is for multicast traffic. FTOS provides the ability to adjust the scheduling weight for multicast traffic. For example, if the majority of your traffic is multicast, the default configuration might yield greater latency. In this case, allocate more backplane bandwidth for multicast using the command queue multicast bandwidth-percent from CONFIGURATION mode. View your configuration using the command show queue backplane multicast bandwidth-percentage. Figure 30-10. Tuning the Central Scheduler for Multicast FTOS#show queue backplane multicast bandwidth-percent Configured multicast bandwidth percentage is 80 676 | Multicast Features