11-13-2015 01:12 PM - edited 03-17-2019 04:54 AM
2911 - 15.2(4)M6a - T1 WAN
I'm having difficulty figuring out why I get intermittent ef marked packets in the class-default queue. The matched voice ACL (UDP based port range) counters agree with the realtime counters exactly.
#sh policy-map int gi0/0 in
GigabitEthernet0/0
Service-policy input: MarkInbound
Class-map: MarkVoice (match-any)
189681 packets, 19213876 bytes
30 second offered rate 0000 bps, drop rate 0000 bps
Match: access-group name VoiceDataACL
189681 packets, 19213876 bytes
30 second rate 0 bps
QoS Set
dscp ef
Packets marked 189681
sh ip access-lists VoiceDataACL
Extended IP access list VoiceDataACL
10 permit udp any range 16384 32767 any range 16384 32767 (189681 matches)
sh policy-map int se0/0/0:0 out class class-default
<truncated output>
Class-map: class-default (match-any)
1784475 packets, 1527263608 bytes
30 second offered rate 75000 bps, drop rate 0000 bps
Match: any
Queueing
queue limit 64 packets
(queue depth/total drops/no-buffer drops) 0/100005/0
(pkts output/bytes output) 1786915/1455101962
bandwidth remaining 4%
Exp-weight-constant: 9 (1/512)
Mean queue depth: 0 packets
dscp Transmitted Random drop Tail drop Minimum Maximum Mark
pkts/bytes pkts/bytes pkts/bytes thresh thresh prob
default 1772601/1453731273 8331/9553582 91453/124110423 20 40 1/10
ef 14314/1370689 3/472 218/34293 36 40 1/10
The problem is manifested on WAN calls where the far end hears degraded voice quality, but the near end has no problems. How can ef marked packets get queued in the class-default class-map?
This same config is present in dozens of other routers, but this one site is the only one with errant ef packets.
I appreciate any help.
Solved! Go to Solution.
06-10-2016 07:20 AM
Definitely a code problem. Short version: after many weeks of chasing them, Cisco dropped in a test version of IOS code. Problem cleared. Cisco asked to remove test code, problem came back. We are waiting for Cisco to release a mainline version with the fix. According to the emails:
They have committed the fix to the following images: 15.6(2)T1 and 15.4(3)M6
cco release date (15.6(2)T1) is 6/21/2016
cco release date (15.4(3)M6) is 7/29/2016
The same fix will be committed to other versions like 15.5 and 15.6M but they will published by Sept or Oct this year. Looking for bug ID...
11-13-2015 01:19 PM
Here is the full class and policy map configs:
class-map match-any realtime
match ip dscp ef
class-map match-any MarkBusinessData
match access-group name BusinessDataACL
class-map match-any Business
match ip dscp cs2 af21 af22 af23
class-map match-any MarkCallSetup
match access-group name CallSetupACL
class-map match-any Video
match ip dscp cs4 af41 af42 af43
class-map match-any MarkMissionCritical
match access-group name MissionCriticalACL
class-map match-any MarkGeneralData
match access-group name GeneralDataACL
class-map match-any General
match ip dscp cs1 af11 af12 af13
class-map match-any MarkVoice
match access-group name VoiceDataACL
class-map match-any MarkVideo
match access-group name VideoDataACL
class-map match-any MissionCritical
match ip dscp cs3 af31 af32 af33 cs6 cs7
!
policy-map etm-Company
class realtime
priority 768
police 768000 conform-action transmit exceed-action set-dscp-transmit af41 violate-action set-dscp-transmit af41
class Video
bandwidth remaining percent 39
random-detect dscp-based
class MissionCritical
bandwidth remaining percent 39
random-detect dscp-based
class Business
bandwidth remaining percent 16
random-detect dscp-based
class General
bandwidth remaining percent 1
random-detect dscp-based
class class-default
bandwidth remaining percent 4
random-detect dscp-based
policy-map shape-etm-Company
class class-default
shape average 1536000
service-policy etm-Company
policy-map MarkInbound
class MarkVoice
set ip dscp ef
class MarkVideo
set ip dscp af41
class MarkCallSetup
set ip dscp af31
class MarkMissionCritical
set ip dscp af32
class MarkBusinessData
set ip dscp af21
class MarkGeneralData
set ip dscp af11
class class-default
set ip dscp default
06-10-2016 04:58 AM
Did you find any solution for this problem? I've ran to this same issue at a customer. There are a bunch of 2901 routers with same IOS, almost same configuration (there are 2,10,100M links), and about 5 from the 40 routers cannot match RTP traffic based on dscp ef markings. I've switched on dscp-based WRED too on class default, and I've seen the same, there are the dscp ef marked packets instead of the LLQ. The routers run with IOS 15.1.3T image. These are voice gateways with ISDN BRI or FXS voice interfaces, this voice traffic goes through the WAN connection. Almost every routers do it's job fine, but this 5 don't. I've double-checked everything many times, but I couldn't find the solution. I did not find any relevant bug in the IOS release notes...
Regards,
Zsolt
06-10-2016 07:20 AM
Definitely a code problem. Short version: after many weeks of chasing them, Cisco dropped in a test version of IOS code. Problem cleared. Cisco asked to remove test code, problem came back. We are waiting for Cisco to release a mainline version with the fix. According to the emails:
They have committed the fix to the following images: 15.6(2)T1 and 15.4(3)M6
cco release date (15.6(2)T1) is 6/21/2016
cco release date (15.4(3)M6) is 7/29/2016
The same fix will be committed to other versions like 15.5 and 15.6M but they will published by Sept or Oct this year. Looking for bug ID...
06-10-2016 07:47 AM
Thanks for your fast response,
Thanks!
Regards,
Zsolt
06-10-2016 11:57 AM
CSCuy23951
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCuy23951
Symptom: Priority packets fall under class-default
Basic config to recreate issue:
policy-map BU
class BU
priority
class class-default
random-detect dscp-based >>>> not needed, added to match affected packets against DSCP marked by BU class-map
F340.22.17-2921-2#sh policy-map interface
Serial0/2/0:0
Service-policy output: BU
queue stats for all priorty classes:
Queueing
queie limit 64 packets
(queue depth/total drops/no-buffer drops)0/0/0
(pks output/bytes output) 189858/263143188
Class-map: BU (match-any)
189858 packets, 263143188 bytes
30 second offered rate 1463000 bps, drop rate 0000 bps
Match: dscp ef(46) >>>>>> EF
189858 packets, 263143188 bytes
30 second rate 1463000 bps
Priority: Strict, b/w exceed drops: 0
Class-map: class-default(match-any)
174 packets, 13707 bytes
30 second offered rate 0000 bps, drop rate 0000 bps
Match: any
queue limit 64 packets
(queue depth/total drops/no-buffer drops) 0/0/0
(pkts output/bytes output) 176/16479
Exp-weight-constant: 9 (1/512)
Mean queue depth: 0 packets
dscp Transmitted Random drop Tail drop Maximum Mark
pkts/bytes pkts/bytes pkts/bytes thresh thresh prob
default 175/13731 0/0 0/0 20 40 1/10
ef 2/2772 0/0 0/0 36 40 1/10
Conditions:
Channelized interface VWIC
Tested a hwic-1t and build-in Gig Int, no issue.
Workaround:
Change the queueing policy from priority to bandwidth results in the problem no occurring or using just the queueing policy and removing the shaping policy results in the problem not occurring.
Further Problem Description:
There is a clear interaction between channelized interfaces and QoS.
06-14-2016 02:49 AM
Unfortunately it's not match to my issue, I use built-in gig ports as wan connection in this case. I've tried remove the shaping from the multi-level QoS config, but there was nothing changed. I've tried many kind of changes, remove other classes, change the name of the classes to re-order the queues on the output, but nothing worked. I hope, the upgrade what you mentioned will resolve this issue. The strange thing is, only five of the fifty routers are affected, but this five always fail. The other ones work perfectly with the same configuration.
12-27-2016 05:08 PM
Hi, I wrote this Bug regarding EF drops on VWICs.
We never found problems with GigaB interfaces, please notice that there are some traffic that will always "fall" under class-default but its policies does not take any effect on the traffic, for example BFD.
Note: I think one of my peers was working on similar issue on GigaB Interfaces but on ASR1Ks, ISRg2s no issues were found on your tests.
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