Hi
I am to understand how the queue-limit is calculated on ASR Version 16.03.02
The configuration for the CBWFQ is as follows
policy-map WAN-OUT-CBWFQ-10M-EF
class EF
priority 10240
class Routing
bandwidth remaining percent 3
class AF4
bandwidth remaining percent 25
random-detect dscp-based
random-detect dscp 32 180 360
random-detect dscp 34 180 360
queue-limit 400 packets
class AF3
bandwidth remaining percent 10
random-detect dscp-based
random-detect dscp 24 180 360
random-detect dscp 26 100 200
random-detect dscp 28 100 200
queue-limit 400 packets
class AF2
bandwidth remaining percent 10
random-detect dscp-based
random-detect dscp 18 75 150
queue-limit 200 packets
class class-default
bandwidth remaining percent 52
queue-limit 1000 packets
fair-queue
random-detect dscp-based
random-detect dscp 0 600 900
policy-map WAN-OUT-SHAPE-50M-10M-EF
description parent policy for interface shaping
class class-default
shape average 47000000
service-policy WAN-OUT-CBWFQ-10M-EF
interface GigabitEthernet0/0/2
bandwidth 51200
service-policy output WAN-OUT-SHAPE-50M-10M-EF
hold-queue 2000 in
hold-queue 2000 out
When I look at the policy output on the interface I see the default queue-limit for the parent policy is 195 packets how is this calculated please, I understand priority class defaults to 512 so I need to account for that in the configuration still, but its the parent queue-limit that I am trying to understand. I could manually set this, but not sure what to set it to if I did that?
I have read "The router uses 50 ms of 1500-byte packets but never less than 64 packets" but I am not sure what this means?
show policy-map interface g0/0/2
GigabitEthernet0/0/2
Service-policy output: WAN-OUT-SHAPE-50M-10M-EF
Class-map: class-default (match-any)
1466948249 packets, 518033603132 bytes
30 second offered rate 11226000 bps, drop rate 0000 bps
Match: any
Queueing
queue limit 195 packets
(queue depth/total drops/no-buffer drops) 0/410947/0
(pkts output/bytes output) 1466454655/517738905408
shape (average) cir 47000000, bc 188000, be 188000
target shape rate 47000000
Service-policy : WAN-OUT-CBWFQ-10M-EF
queue stats for all priority classes:
Queueing
queue limit 512 packets
(queue depth/total drops/no-buffer drops) 0/0/0
(pkts output/bytes output) 39584544/8419136844
Class-map: EF (match-any)
39584544 packets, 8419136844 bytes
30 second offered rate 143000 bps, drop rate 0000 bps
Match: ip dscp ef (46)
Priority: 10240 kbps, burst bytes 256000, b/w exceed drops: 0
Class-map: Routing (match-any)
4125680 packets, 384082015 bytes
30 second offered rate 11000 bps, drop rate 0000 bps
Match: ip dscp cs6 (48)
Match: ip dscp cs7 (56)
Queueing
queue limit 195 packets
(queue depth/total drops/no-buffer drops) 0/0/0
(pkts output/bytes output) 4052728/373880995
bandwidth remaining 3%
Class-map: AF4 (match-any)
85805928 packets, 80746182000 bytes
30 second offered rate 4018000 bps, drop rate 0000 bps
Match: ip dscp cs4 (32) af41 (34)
Queueing
queue limit 400 packets
(queue depth/total drops/no-buffer drops) 0/0/0
(pkts output/bytes output) 85805928/80746182000
bandwidth remaining 25%
Exp-weight-constant: 4 (1/16)
Mean queue depth: 1 packets
dscp Transmitted Random drop Tail drop Minimum Maximum Mark
pkts/bytes pkts/bytes pkts/bytes thresh thresh prob
cs4 77142216/74622342688 0/0 0/0 180 360 1/10
af41 8663712/6123839312 0/0 0/0 180 360 1/10
Class-map: AF3 (match-any)
1384871 packets, 548506638 bytes
30 second offered rate 2000 bps, drop rate 0000 bps
Match: ip dscp af31 (26) af32 (28)
Queueing
queue limit 400 packets
(queue depth/total drops/no-buffer drops) 0/89/0
(pkts output/bytes output) 1384782/548375443
bandwidth remaining 10%
Exp-weight-constant: 4 (1/16)
Mean queue depth: 1 packets
dscp Transmitted Random drop Tail drop Minimum Maximum Mark
pkts/bytes pkts/bytes pkts/bytes thresh thresh prob
cs3 0/0 0/0 0/0 180 360 1/10
af31 1384782/548375443 37/53901 52/77294 100 200 1/10
af32 0/0 0/0 0/0 100 200 1/10
Class-map: AF2 (match-any)
0 packets, 0 bytes
30 second offered rate 0000 bps, drop rate 0000 bps
Match: ip dscp af21 (18)
Queueing
queue limit 200 packets
(queue depth/total drops/no-buffer drops) 0/0/0
(pkts output/bytes output) 0/0
bandwidth remaining 10%
Exp-weight-constant: 4 (1/16)
Mean queue depth: 0 packets
dscp Transmitted Random drop Tail drop Minimum Maximum Mark
pkts/bytes pkts/bytes pkts/bytes thresh thresh prob
af21 0/0 0/0 0/0 75 150 1/10
Class-map: class-default (match-any)
1336047225 packets, 427935696759 bytes
30 second offered rate 7048000 bps, drop rate 0000 bps
Match: any
Queueing
queue limit 1000 packets
(queue depth/total drops/no-buffer drops/flowdrops) 0/410858/0/379263
(pkts output/bytes output) 1335626673/427651330126
bandwidth remaining 52%
Fair-queue: per-flow queue limit 250 packets
Exp-weight-constant: 4 (1/16)
Mean queue depth: 2 packets
dscp Transmitted Random drop Tail/Flow drop Minimum Maximum Mark
pkts/bytes pkts/bytes pkts/bytes thresh thresh prob
default1323502480/417465363429 10871/8145742 12068/6635487 600 900 1/10
1 2068/397056 0/0 0/0 250 500 1/10
2 11563620/9932697223 2012/1927728 6373/2760751 250 500 1/10
4 99972/30288534 10/2368 107/14151 250 500 1/10
cs1 1973/175307 0/0 4/264 281 500 1/10
af11 21/3872 0/0 0/0 437 500 1/10
af12 100100/130622932 4/6056 16/8407 375 500 1/10
af22 3/600 0/0 0/0 375 500 1/10
cs3 24368/20909922 0/0 13/1318 343 500 1/10
cs5 331817/70813170 4/856 113/24182 406 500 1/10
50 113/41573 0/0 0/0 250 500 1/10
54 138/16508 0/0 0/0 250 500 1/10
The other worry I have is the mean queue depth for some classes are showing >0 packets, which suggests class queue-limits are not big enough.
2K is a fairly large hold queue on the interface. I understand its not recommended to increase too much due to increase latencys so not sure I want to increase much more than that?
Can anyone assist with helping me understand this please?
