[c-nsp] shaper in policy-map is not taken into account
Velimir Filipov
vfilipov at evolink.com
Wed Mar 19 11:45:36 EDT 2014
Martin,
Here its how it works.
All the traffic entering class INGRESS-TRAFFIC-CLASS is shaped at 19 Mbps.
Once it's shaped, you recall another service policy (child policy) which once again do some action to the packets.
So in your case, the bandwidth of 19 Mbps of class INGRESS-TRAFFIC-CLASS is shared among the 2 classes in the child policy - VOIP-INGRESS-TRAFFIC-CLASS and class-default
About your second question, you got it right.
Cheers.
Wednesday, March 19, 2014, 1:09:02 PM, you wrote:
> Velimir,
> thank you for pointing this out! Based on "Understanding Queue Limits
> and Output Drops on Cisco IOS Software
> Platforms"(http://www.cisco.com/c/en/us/support/docs/routers/7200-series-routers/110850-queue-limit-output-drops-ios.html),
> the default queue depth in case of pre-HQF is 64 packets for each
> class. I was able to confirm this with "sh policy-map int" command and
> also saw egress buffer drops in "sh int" output. Once I increased the
> queue-limit to 4096 packets, the output drops disappeared.
> Two other questions based on the "sh policy-map int" output seen below:
> В Service-policy output: SHAPER-INGRESS-TRAFFIC
> В В Class-map: INGRESS-TRAFFIC-CLASS (match-all)
> В В В 1141774 packets, 860950405 bytes
> В В В 30 second offered rate 4520000 bps, drop rate 0 bps
> В В В Match: access-group name INGRESS-TRAFFIC-ACL
> В В В Traffic Shaping
> В В В В В В Target/Average В Byte В Sustain В Excess В В Interval В Increment
> В В В В В В В Rate В В В В В Limit В bits/int В bits/int В (ms) В В В (bytes)
> В В В В В 19000000/19000000 В 118750 475000 В В 475000 В В 25 В В В В 59375
> В В В В Adapt В Queue В В Packets В Bytes В В Packets В Bytes В В Shaping
> В В В В Active Depth В В В В В В В В В В В В Delayed В Delayed В Active
> В В В В - В В В 0 В В В В 1141740 В 860947825 105341 В В 127469015 no
> В В В Service-policy : VOIP-INGRESS-TRAFFIC-POLICY
> В В В В Class-map: VOIP-INGRESS-TRAFFIC-CLASS (match-all)
> В В В В В 0 packets, 0 bytes
> В В В В В 30 second offered rate 0 bps, drop rate 0 bps
> В В В В В Match: access-group name VOIP-INGRESS-TRAFFIC-ACL
> В В В В В Queueing
> В В В В В В Strict Priority
> В В В В В В Output Queue: Conversation 264
> В В В В В В Bandwidth 4500 (kbps) Burst 112500 (Bytes)
> В В В В В В (pkts matched/bytes matched) 0/0
> В В В В В В (total drops/bytes drops) 0/0
> В В В В Class-map: class-default (match-any)
> В В В В В 1141774 packets, 860950405 bytes
> В В В В В 30 second offered rate 4520000 bps, drop rate 0 bps
> В В В В В Match: any
> В В В В В Queueing
> В В В В В В Output Queue: Conversation 265
> В В В В В В Bandwidth 14500 (kbps)Max Threshold 4096 (packets)
> В В В В В В (pkts matched/bytes matched) 105341/127469015
> В В В В (depth/total drops/no-buffer drops) 0/0/0
> В В Class-map: class-default (match-any)
> В В В 1512 packets, 97474 bytes
> В В В 30 second offered rate 0 bps, drop rate 0 bps
> В В В Match: any
> 1) Am I correct that shaper applied in parent policy-map also shapes
> all the traffic classes in child policy-maps, i.e. this 19Mbps shaper
> is shared by three traffic classes: traffic in policy-map
> VOIP-INGRESS-TRAFFIC-POLICY(it has "VOIP-INGRESS-TRAFFIC-CLASS" and
> "class-default" classes) and traffic in policy-map
> SHAPER-INGRESS-TRAFFIC(it has only "class-default" class besides
> nested policy-map VOIP-INGRESS-TRAFFIC-POLICY).
> 2) How is the traffic classified in case of multiple classes and
> nested policy-maps? Based on the example above, does it works in a way
> that if traffic matches "INGRESS-TRAFFIC-ACL" access-list AND
> "VOIP-INGRESS-TRAFFIC-ACL" access-list, then it's put into
> "VOIP-INGRESS-TRAFFIC-CLASS" class? If traffic matches only
> "INGRESS-TRAFFIC-ACL" access-list and not "VOIP-INGRESS-TRAFFIC-ACL"
> access-list, then it's put into first default-class? Finally, if
> traffic does not match "INGRESS-TRAFFIC-ACL", then it's put into last
> default-class(the one which has 1512 packets at the moment)?
> thanks,
> Martin
> On 3/14/14, Velimir Filipov <vfilipov at evolink.com> wrote:
>>
>> Hello,
>>
>> When В the queues are full packet drop still occurs.
>>
>> So I suggest that there was a peak traffic at some point during that 30 sec
>> period, which filled up the queue and resulted in dropped packets.
>>
>> You can increase the queue size or the conform interval to achieve lower
>> drop rates for peak traffic, but might result in longer delays.
>>
>> Good luck.
>>
>> --
>> Best regards,
>> Velimir Filipov
>> Network Administrator
>>
>>
>> EVOLINK AD
>> 86 Hristo Maksimov Str.
>> 1111 Sofia, Bulgaria
>>
>> Phone: В В + 359 2 969 15 13
>> Mobile: В + 359 887 808 757
>> Fax: В В В В + 359 2 9710 084
>> Email: В В vfilipov at evolink.com
>> www.evolink.com
>>
>> Thursday, March 13, 2014, 5:49:03 PM, you wrote:
>>
>>> Hi,
>>
>>> I have configured 20Mbps shaper("shape average 20000000") in
>>> SHAPER-EGRESS-TRAFFIC policy-map under class-default traffic class:
>>
>>> В В Service-policy output: SHAPER-EGRESS-TRAFFIC
>>
>>> В В В В Class-map: class-default (match-any)
>>> В В В В В В 306585 packets, 88611267 bytes
>>> В В В В В В 30 second offered rate 2107000 bps, drop rate 17000 bps
>>> В В В В В В Match: any
>>> В В В В В В Traffic Shaping
>>> В В В В В В В В В В В Target/Average В В Byte В В Sustain В В Excess В В В Interval
>>> В Increment
>>> В В В В В В В В В В В В В Rate В В В В В В В В В В Limit В bits/int В bits/int В (ms)
>>> В В В В В (bytes)
>>> В В В В В В В В В 20000000/20000000 В 125000 500000 В В В 500000 В В В 25 В В В
>>> В В В 62500
>>
>>> В В В В В В В В Adapt В Queue В В В В Packets В В Bytes В В В В Packets В В Bytes В
>>> В В Shaping
>>> В В В В В В В В Active Depth В В В В В В В В В В В В В В В В В В В В В В В В Delayed В
>>> Delayed В В Active
>>> В В В В В В В В - В В В В В 0 В В В В В В В В 306384 В В В 88306481 В 6992 В В В В В
>>> 9487573 В В no
>>
>>> В В В В В В Service-policy : VOIP-EGRESS-TRAFFIC-POLICY
>>
>>> В В В В В В В В Class-map: VOIP-EGRESS-TRAFFIC-CLASS (match-all)
>>> В В В В В В В В В В 0 packets, 0 bytes
>>> В В В В В В В В В В 30 second offered rate 0 bps, drop rate 0 bps
>>> В В В В В В В В В В Match: access-group name VOIP-EGRESS-TRAFFIC-ACL
>>> В В В В В В В В В В Queueing
>>> В В В В В В В В В В В В Strict Priority
>>> В В В В В В В В В В В В Output Queue: Conversation 264
>>> В В В В В В В В В В В В Bandwidth 4500 (kbps) Burst 112500 (Bytes)
>>> В В В В В В В В В В В В (pkts matched/bytes matched) 0/0
>>> В В В В В В В В В В В В (total drops/bytes drops) 0/0
>>
>>> В В В В В В В В Class-map: class-default (match-any)
>>> В В В В В В В В В В 306585 packets, 88611267 bytes
>>> В В В В В В В В В В 30 second offered rate 2107000 bps, drop rate 17000 bps
>>> В В В В В В В В В В Match: any
>>
>>
>>> During the last 30 seconds, policy-map has allowed traffic at 2.1Mbps
>>> in average and dropped 17kbps in average. Why is my policy-map
>>> dropping traffic while it should shape it? And shaping is configured
>>> to 20Mbps not around 2Mbps..
>>
>>
>>
>>> regards,
>>> Martin
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