Just to add some notes on the issues we experienced related to this bug - we had one-way voice audio issues (outbound from the site so our users could not hear it) where audio was garbled, missing, or sounded like wind blowing over the audio. We have a 2911 router running "c2900-universalk9-mz.SPA.153-3.M5.bin" code. In the bug notice, it states that removing the shaping results in the problem not occurring, but just to clarify what we have seen, it has solved the voice audio issues, but it has also started classifying other traffic (not service-affecting) with our QoS policy where many higher queues have a small number of packets being placed in default - see below the AFXX DSCP values that end up in the default queue. This should only transmit default these other DSCP categories should be in higher queues - so removing shaping changes the behavior and solves the audio issue, but this bug still affects the QoS policy - our QoS policy is identical on 100+ WAN routers on the same MPLS network, but this behavior only occurs on sites with a single WAN T1:
Class-map: class-default (match-any)
41160888 packets, 47835376202 bytes
30 second offered rate 1682000 bps, drop rate 298000 bps
Match: any
Queueing
queue limit 256 packets
(queue depth/total drops/no-buffer drops) 69/6590448/0
(pkts output/bytes output) 38164090/41040856611
bandwidth remaining 4%
Exp-weight-constant: 9 (1/512)
Mean queue depth: 145 packets
dscp Transmitted Random drop Tail drop Minimum Maximum Mark
pkts/bytes pkts/bytes pkts/bytes thresh thresh prob
default 38155948/41039729557 443891/625277642 6146404/8682814051 160 192 1/10
af11 959/236862 0/0 0/0 32 40 1/10
af12 32/7363 0/0 0/0 28 40 1/10
af13 861/221856 0/0 0/0 24 40 1/10
af21 2089/246377 0/0 0/0 32 40 1/10
af23 596/73051 0/0 0/0 24 40 1/10
af31 225/11512 0/0 0/0 32 40 1/10
af32 2817/279740 0/0 0/0 28 40 1/10
ef 563/50293 0/0 0/0 36 40 1/10
