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PowerConnect B-Series FCX Configuration Guide
53-1002266-01
Scheduling
17
NOTE
Queue cycles on the PowerConnect devices are based on bytes. These devices service a given
number of bytes (based on weight) in each queue cycle. FES and BI/FI queue cycles are based
on packets. The bytes-based scheme is more accurate than a packets-based scheme if
packets vary greatly in size.
•
Strict priority (SP) – SP ensures service for high priority traffic. The software assigns the
maximum weights to each queue, to cause the queuing mechanism to serve as many packets
in one queue as possible before moving to a lower queue. This method biases the queuing
mechanism to favor the higher queues over the lower queues.
For example, strict queuing processes as many packets as possible in qosp3 before processing
any packets in qosp2, then processes as many packets as possible in qosp2 before processing
any packets in qosp1, and so on.
•
Hybrid WRR and SP – This configurable queueing mechanism combines both the strict priority
and weighted round robin mechanisms. The combined method enables the Dell PowerConnect
device to give strict priority to delay-sensitive traffic such as VoIP traffic, and weighted round
robin priority to other traffic types.
By default, when you select the combined SP and WRR queueing method, the Dell
PowerConnect device assigns strict priority to traffic in qosp7 and qosp6, and weighted round
robin priority to traffic in qosp0 through qosp5. Thus, the Dell PowerConnect device schedules
traffic in queue 7 and queue 6 first, based on the strict priority queueing method. When there
is no traffic in queue 7 and queue 6, the device schedules the other queues in round-robin
fashion from the highest priority queue to the lowest priority queue.
NOTE
Stackable devices that are operating as members of a stack reserve queue 7 for stacking
functions. For more information, see
“QoS for stackable devices”
on page 595.
By default, when you specify the combined SP and WRR queuing method, the system balances
the traffic among the queues as shown in
Table 102
. If desired, you can change the default
bandwidth values as shown in the section
“Bandwidth allocations of the hybrid WRR and SP
queues.”
on page 607.
TABLE 102
Default bandwidth for combined SP and WRR queueing methods
Queue
Default bandwidth
qosp7
Strict priority (highest priority)
qosp6
Strict priority
qosp5
25%
qosp4
15%
qosp3
15%
qosp2
15%
qosp1
15%
qosp0
15% (lowest priority)
Содержание PowerConnect B-FCXs
Страница 1: ...53 1002266 01 18 March 2011 PowerConnect B Series FCX Configuration Guide ...
Страница 136: ...94 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Viewing information about software licenses 4 ...
Страница 228: ...186 PowerConnect B Series FCX Configuration Guide 53 1002266 01 PowerConnect B Series FCX hitless stacking 5 ...
Страница 229: ...PowerConnect B Series FCX Configuration Guide 187 53 1002266 01 PowerConnect B Series FCX hitless stacking 5 ...
Страница 230: ...188 PowerConnect B Series FCX Configuration Guide 53 1002266 01 PowerConnect B Series FCX hitless stacking 5 ...
Страница 248: ...206 PowerConnect B Series FCX Configuration Guide 53 1002266 01 IPv6 management commands 7 ...
Страница 346: ...304 PowerConnect B Series FCX Configuration Guide 53 1002266 01 802 1s Multiple Spanning Tree Protocol 8 ...
Страница 374: ...332 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Jumbo frame support 9 ...
Страница 424: ...382 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Virtual Switch Redundancy Protocol VSRP 10 ...
Страница 568: ...526 PowerConnect B Series FCX Configuration Guide 53 1002266 01 CLI examples 14 ...
Страница 588: ...546 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Sample application 15 ...
Страница 674: ...632 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Enabling or disabling layer 2 switching 19 ...
Страница 684: ...642 PowerConnect B Series FCX Configuration Guide 53 1002266 01 VLAN based mirroring 20 ...
Страница 724: ...682 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Reading CDP packets 23 ...
Страница 768: ...726 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Clearing cached LLDP neighbor information 24 ...
Страница 930: ...888 PowerConnect B Series FCX Configuration Guide 53 1002266 01 26 ...
Страница 948: ...906 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Configuring MLD snooping 27 ...
Страница 962: ...920 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Displaying CPU utilization statistics 28 ...
Страница 1022: ...980 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Displaying OSPF information 29 ...
Страница 1142: ...1100 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Clearing diagnostic buffers 30 ...
Страница 1258: ...1216 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Using Secure copy with SSH2 33 ...
Страница 1314: ...1272 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Displaying port security information 35 ...
Страница 1348: ...1306 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Example configurations 36 ...
Страница 1406: ...1364 PowerConnect B Series FCX Configuration Guide 53 1002266 01 IP source guard 39 ...
Страница 1422: ...1380 PowerConnect B Series FCX Configuration Guide 53 1002266 01 SNMP v3 Configuration examples 40 ...