08-20-2012 05:34 PM - edited 03-04-2019 05:19 PM
Hi team,
I am having some trouble with my WAN link. We have replication data traversing the WAN from our head office to our DR site constantly. With this traffic marked I can see that even though the bandwidth percent is at 30%, it continually rises to up around 85-90% of the link.
I understand that this is how the command should work, however it seems that it is causing issues becasue other traffic that is prioritised higher is not getting through fast enough even though it is a small amount of traffic.
What I want is for the SAN_REPLICATION data class map to stay at a certain mbps value and not exceed it. I understand that the commands do only use the rest of the traffic when there is nothing competing but for some reason having this use so much bandwidth is severely impacting the TCC_DIRECT and BSADB1 traffic, which are both time sensitive apps.
class-map match-all TCC_DIRECT
description DATA_TO_TCC_MELB
match dscp af32
class-map match-all SAN_REPLICATION
description DATA_FROM_VLAN_5_(SAN)
match dscp cs1
class-map match-all VIDEO_QoS
description DATA_FROM_VLAN_7_(VIDEO)
match dscp cs5
class-map match-all BSADB1
description DATA_FROM_BSADB1
match dscp cs3
!
!
policy-map QoS_POLICY
class SAN_REPLICATION
bandwidth percent 30
class VIDEO_QoS
priority percent 10
class BSADB1
bandwidth percent 7
class TCC_DIRECT
bandwidth percent 7
class class-default
fair-queue
policy-map SHAPE_TRAFFIC_20Mbps
class class-default
shape average 20000000
service-policy QoS_POLICY
You can see in the below command how much of the 20mbps it uses
sh policy-map interface fa0/1
FastEthernet0/1
Service-policy output: SHAPE_TRAFFIC_20Mbps
Class-map: class-default (match-any)
3519814138 packets, 3485395070405 bytes
30 second offered rate 20166000 bps, drop rate 238000 bps
Match: any
Traffic Shaping
Target/Average Byte Sustain Excess Interval Increment
Rate Limit bits/int bits/int (ms) (bytes)
20000000/20000000 125000 500000 500000 25 62500
Adapt Queue Packets Bytes Packets Bytes Shaping
Active Depth Delayed Delayed Active
- 3 3509502603 42797116 867244093 2966129398 yes
Service-policy : QoS_POLICY
Class-map: SAN_REPLICATION (match-all)
2282323520 packets, 2910036574815 bytes
30 second offered rate 18455000 bps, drop rate 156000 bps
Match: dscp cs1 (8)
Queueing
Output Queue: Conversation 265
Bandwidth 30 (%)
Bandwidth 6000 (kbps)Max Threshold 64 (packets)
(pkts matched/bytes matched) 631886976/922640865641
(depth/total drops/no-buffer drops) 0/3600346/285
Class-map: VIDEO_QoS (match-all)
19120396 packets, 9693435746 bytes
30 second offered rate 0 bps, drop rate 0 bps
Match: dscp cs5 (40)
Queueing
Strict Priority
Output Queue: Conversation 264
Bandwidth 10 (%)
Bandwidth 2000 (kbps) Burst 50000 (Bytes)
(pkts matched/bytes matched) 3326730/1543851666
(total drops/bytes drops) 3525/4315479
Class-map: BSADB1 (match-all)
521509844 packets, 203628804995 bytes
30 second offered rate 1310000 bps, drop rate 11000 bps
Match: dscp cs3 (24)
Queueing
Output Queue: Conversation 266
Bandwidth 7 (%)
Bandwidth 1400 (kbps)Max Threshold 64 (packets)
(pkts matched/bytes matched) 135182018/42882862506
(depth/total drops/no-buffer drops) 3/2446771/83
Class-map: TCC_DIRECT (match-all)
1689609 packets, 435893589 bytes
30 second offered rate 51000 bps, drop rate 0 bps
Match: dscp af32 (28)
Queueing
Output Queue: Conversation 267
Bandwidth 7 (%)
Bandwidth 1400 (kbps)Max Threshold 64 (packets)
(pkts matched/bytes matched) 764569/176799062
(depth/total drops/no-buffer drops) 0/0/0
Class-map: class-default (match-any)
695170913 packets, 361600541180 bytes
30 second offered rate 346000 bps, drop rate 67000 bps
Match: any
Queueing
Flow Based Fair Queueing
Maximum Number of Hashed Queues 256
(total queued/total drops/no-buffer drops) 0/4260811/143
Any help would be great, thank you.
08-20-2012 08:25 PM
Remember to set up the bandwidth command on the interface!
08-21-2012 08:40 AM
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Posting
You might embed a policer in the SAN_REPLICATION class, but I would first suggest setting your shaper's Tc to about 10ms, if larger, and reducing the SAN_REPLICATION class bandwidth reservation. (Normally everyone thinks of class bandwidth as bandwidth allowances, but it also impacts scheduler class packet selection too. If the other classes will leave sufficient bandwidth, you might even try just 1% for SAN_REPLICATION.)
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