02-19-2014 09:51 AM - edited 03-04-2019 10:23 PM
please see the attached "show policy-map int" in my core MPLS router. here are some facts about my policy-map QOS-WAN:
VOIP : get 40% bandwidth,
Multimedia: get 36% bandwidth, by default, the router set the queue limit to 13477(packets)
BUSCRIT: get 18% bandwidth, by default, the router set the queue limit to 6738(packets)
Default class: get 6% bandwidth, by default, the router set the queue limit to 2246( packets)
It looked the queue limit for each queue is set by the router in proporsion to its bandwidth allocated.
I also saw the default class in class-default got a lot tail drops. I would like to twist the queue limit and min & max thresholds a little bit to have minimum drops for my default class, more drops for the dscp cs1 traffic.
Can someone please help?
7609-A#show policy-map int
ATM3/0/0.777: VC 2/777
Service-policy output: QOS-WAN
queue stats for all priority classes:
queue limit 14975 (packets)
(queue depth/total drops/no-buffer drops) 0/0/0
(pkts queued/bytes queued) 39359214/3102276681
Class-map: VOIP (match-any)
39349678 packets, 3101570482 bytes
5 minute offered rate 1972000 bps, drop rate 0 bps
Match: ip dscp ef
Priority: 40% (59904 kbps), burst 1497600 (bytes)
QoS Set
ip dscp ef
Packets marked 39359215
Class-map: MULTIMEDIA (match-any)
229513 packets, 135856662 bytes
5 minute offered rate 663000 bps, drop rate 0 bps
Match: ip dscp af41
Match: ip dscp af31
Queueing
queue limit 13477 (packets)
(queue depth/total drops/no-buffer drops) 0/0/0
(pkts queued/bytes queued) 229513/135856662
bandwidth remaining 60% (53913 kbps)
QoS Set
ip dscp af31
Packets marked 229513
Class-map: BUSCRIT (match-any)
1052397 packets, 284828937 bytes
5 minute offered rate 118000 bps, drop rate 0 bps
Match: ip dscp af21
Match: ip dscp af22
Match: ip dscp cs2
Match: ip dscp cs6
Match: ip dscp cs3
Match: ip dscp cs7
Queueing
queue limit 6738 (packets)
(queue depth/total drops/no-buffer drops) 0/0/0
(pkts queued/bytes queued) 1053010/285008109
bandwidth remaining 30% (26956 kbps)
Class-map: class-default (match-any)
221792641 packets, 148286927557 bytes
5 minute offered rate 75829000 bps, drop rate 0 bps
Match: any
Queueing
queue limit 2246 (packets)
(queue depth/total drops/no-buffer drops/flowdrops) 0/10078/0/10078
(pkts queued/bytes queued) 221933367/148373542301
Fair-queue: per-flow queue limit 561
Exp-weight-constant: 9 (1/512)
Mean queue depth: 0
class Transmitted Random drop Tail/Flow drop Minimum Maximum Mark
pkts/bytes pkts/bytes pkts/bytes thresh thresh prob
default 221807441/148345495442 0/0 10078/15233734 1051 1123 1/10
cs1 79290/10238677 0/0 0/0 631 1123 1/10
af13 25/9550 0/0 0/0 701 1123 1/10
cs5 17868/3073296 0/0 0/0 911 1123 1/10
cs7 19/1786 0/0 0/0 1051 1123 1/10
7609-A#
thanks,
Alison
02-19-2014 10:58 AM
Hello.
Actually your drops statistics for class-default DE looks good, because for the whole history there were about
10078/221807441 = 0,004% drops.
But anyway the drops are "flowdrops" that means that single flow bursted over "per-flow queue limit 561", so I would not worry about DE (at least on the interface).
PS: CS1 were no more than 79290 packets totally, so no reason to tune it.
PS2: my primary concern is that your configuration requires queue of about 20K packets on the physical interface - not sure if your device have them. I would say that summary queue of 2K-3K packets should be enough for 150M link.
02-19-2014 11:50 AM
Thanks for posting and confirming.. which made me feel better.
I didn't get what you said in PS2. I attached the interface configuration and show interface command. I could not find anything about queue from output.
interface ATM3/0/0
no ip address
ip route-cache flow
logging event subif-link-status
!
interface ATM3/0/0.777 point-to-point
description MPLS EPVC
ip address 10.17.1.253 255.255.255.252
pvc 2/777
oam-pvc manage 0
encapsulation aal5snap
service-policy out QOS-WAN
ATM3/0/0 is up, line protocol is up
Hardware is cyBus ENHANCED ATM PA Plus, address is 000f.34b3.02c0 (bia 000f.34b3.02c0)
MTU 4470 bytes, sub MTU 4470, BW 149760 Kbit, DLY 80 usec,
reliability 255/255, txload 98/255, rxload 34/255
Encapsulation ATM, loopback not set
Keepalive not supported
Encapsulation(s): AAL5, PVC mode
8191 maximum active VCs, 1 current VCCs
VC idle disconnect time: 300 seconds
246 carrier transitions
Last input 00:00:00, output 00:00:00, output hang never
Last clearing of "show interface" counters 49w0d
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 939454
Queueing strategy: Class-based queueing
Output queue: 0/40 (size/max)
5 minute input rate 20268000 bits/sec, 10670 packets/sec
5 minute output rate 57676000 bits/sec, 12277 packets/sec
134148383482 packets input, 52069178727130 bytes, 0 no buffer
Received 0 broadcasts (0 IP multicasts)
0 runts, 0 giants, 0 throttles
84 input errors, 89 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
140623034146 packets output, 75441120245009 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
02-25-2014 11:27 AM
I did some research. the hold-queue shoudl be adjusted on the physical interface. or vc-hold-queue under the ATM sub interface.
02-19-2014 11:57 AM
What's the line card you're using?
02-19-2014 12:24 PM
I think it is ws-x6582-2pa.
7609-A#show module
Mod Ports Card Type Model Serial No.
--- ----- -------------------------------------- ------------------ -----------
2 0 2 port adapter Enhanced FlexWAN WS-X6582-2PA JAE10160D8F
3 0 2 port adapter Enhanced FlexWAN WS-X6582-2PA JAB08460320
5 2 Supervisor Engine 720 (Hot) WS-SUP720-BASE SAD075101S0
6 2 Supervisor Engine 720 (Active) WS-SUP720-BASE SAD08010388
Mod MAC addresses Hw Fw Sw Status
--- ---------------------------------- ------ ------------ ------------ -------
2 0017.5923.c3d0 to 0017.5923.c40f 2.2 12.2(18)SXF4 12.2(18)SXF4 Ok
3 0011.2133.81f0 to 0011.2133.822f 1.6 12.2(18)SXF4 12.2(18)SXF4 Ok
5 000e.385f.40cc to 000e.385f.40cf 3.1 7.7(1) 12.2(18)SXF4 Ok
6 000d.2910.0994 to 000d.2910.0997 3.6 8.5(4) 12.2(18)SXF4 Ok
Mod Sub-Module Model Serial Hw Status
---- --------------------------- ------------------ ----------- ------- -------
5 Policy Feature Card 3 WS-F6K-PFC3A SAD075005FP 2.2 Ok
5 MSFC3 Daughterboard WS-SUP720 SAD075308BX 2.2 Ok
6 Policy Feature Card 3 WS-F6K-PFC3A SAD080105KV 2.7 Ok
6 MSFC3 Daughterboard WS-SUP720 SAD080100BX 2.12 Ok
Mod Online Diag Status
---- -------------------
2 Pass
3 Pass
5 Pass
6 Pass
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