You can enable WRED and ECN capabilities per queue for granularity. You can disable these functionality
per queue, and you can also specify the minimum and maximum buffer thresholds for each color-coding
of the packets. You can configure maximum drop rate percentage of yellow and green profiles. You can
set up these parameters for both front-end and backplane ports.
Global Service Pools With WRED and ECN Settings
Support for global service pools is now available. You can configure global service pools that are shared
buffer pools accessed by multiple queues when the minimum guaranteed buffers for the queue are
consumed. S4820T platform support four global service-pools in the egress direction. Two service pools
are used– one for loss-based queues and the other for lossless (priority-based flow control (PFC))
queues. You can enable WRED and ECN configuration on the global service-pools.
You can define WRED profiles and weight on each of the global service-pools for both loss-based and
lossless (PFC) service- pools. The following events occur when you configure WRED and ECN on global
service-pools:
• If WRED/ECN is enabled on the global service-pool with threshold values and if it is not enabled on
the queues, WRED/ECN are not effective based on global service-pool WRED thresholds. The queue
on which the traffic is scheduled must contain WRED/ECN settings, which are enabled for WRED, to
be valid for that traffic.
• When WRED is configured on the global service-pool (regardless of whether ECN on global service-
pool is configured), and one or more queues have WRED enabled and ECN disabled, WRED is
effective for the minimum of the thresholds between the queue threshold and the service-pool
threshold.
• When WRED is configured on the global service-pool (regardless of whether ECN on global service-
pool is configured), and one or more queues are enabled with both WRED and ECN, ECN marking
takes effect. The packets are ECN marked up to shared- buffer limits as determined by the shared-
ratio for that global service-pool.
WRED/ECN configurations for the queues that belong to backplane ports are common to all the
backplane ports and cannot be specified separately for each backplane port granularity. This behavior
occurs to prevent system-level complexities in enabling this support for backplane ports. Also,
WRED/ECN is not supported for multicast packets.
The following table describes the WRED and ECN operations that occur for various scenarios of WRED
and ECN configuration on the queue and service pool. (X denotes not-applicable in the table, 1 indicates
that the setting is enabled, 0 represents a disabled setting. )
Table 65. Scenarios of WRED and ECN Configuration
Queue
Configuration
Service-Pool
Configuration
WRED Threshold
Relationship
Q threshold = Q-
T,
Service pool
threshold = SP-T
Expected Functionality
WRED
ECN
WRED
ECN
0
0
X
X
X
WRED/ECN not applicable
Quality of Service (QoS)
813
Содержание S4820T
Страница 1: ...Dell Configuration Guide for the S4820T System 9 8 0 0 ...
Страница 282: ...Dell 282 Control Plane Policing CoPP ...
Страница 569: ...Figure 62 Inspecting Configuration of LAG 10 on ALPHA Link Aggregation Control Protocol LACP 569 ...
Страница 572: ...Figure 64 Inspecting a LAG Port on BRAVO Using the show interface Command 572 Link Aggregation Control Protocol LACP ...
Страница 573: ...Figure 65 Inspecting LAG 10 Using the show interfaces port channel Command Link Aggregation Control Protocol LACP 573 ...
Страница 617: ...mac address table static multicast mac address vlan vlan id output range interface Microsoft Network Load Balancing 617 ...
Страница 622: ...Figure 81 Configuring Interfaces for MSDP 622 Multicast Source Discovery Protocol MSDP ...
Страница 623: ...Figure 82 Configuring OSPF and BGP for MSDP Multicast Source Discovery Protocol MSDP 623 ...
Страница 624: ...Figure 83 Configuring PIM in Multiple Routing Domains 624 Multicast Source Discovery Protocol MSDP ...
Страница 629: ...Figure 86 MSDP Default Peer Scenario 2 Multicast Source Discovery Protocol MSDP 629 ...
Страница 630: ...Figure 87 MSDP Default Peer Scenario 3 630 Multicast Source Discovery Protocol MSDP ...
Страница 751: ...10 11 5 2 00 00 05 00 02 04 Member Ports Te 1 2 1 PIM Source Specific Mode PIM SSM 751 ...
Страница 905: ...Figure 112 Single and Double Tag First byte TPID Match Service Provider Bridging 905 ...
Страница 979: ...6 Member not present 7 Member not present Stacking 979 ...
Страница 981: ...storm control Storm Control 981 ...
Страница 999: ... Te 1 1 0 INCON Root Rootguard Te 1 2 0 LIS Loopguard Te 1 3 0 EDS Shut Bpduguard Spanning Tree Protocol STP 999 ...
Страница 1103: ...Figure 134 Setup OSPF and Static Routes Virtual Routing and Forwarding VRF 1103 ...