Hello,
I'm facing a strange QoS issue on ASR1001 router (IOS-XE image - asr1001-universalk9.03.13.06.S.154-3.S6-ext.bin).
Topology is pretty simple:
<VOICE INFRA> ---- (Gi0/0/2) ASR1001 (Gi0/0/0) ------ <WAN>
I have interface Gi0/0/2 connected to a VoIP network and interface Gi0/0/0 which is WAN facing. I'm marking all VoIP traffic (in inbound direction of Gi0/0/2) with DSCP EF and I'm trying to give it priority once it's exiting to the WAN cloud. On Gi0/0/0 (WAN facing interface) I have an outbound service-policy (on Gi0/0/0) called SHAPER with a class-default, shaping the traffic to the agreed CIR with the provider - 40mbps and nested service-policy with several classes, one of them which is called VOICE which should be the LLQ:
policy-map SHAPER
class class-default
shape average 38502000
service-policy WAN-QUEUEING
policy-map WAN-QUEUEING
class VOICE-QUEUEING
priority percent 20
class A
bandwidth...
class B
bandwidth...
class C
bandwidth...
The problem is that there are some drops in the VOICE-QUEUEING class although the offered rate seems to be much lower than the configured (7.7mbps)
WAN facing interface (outbound):
show policy-map interface Gi0/0/0 output | s VOICE-QUEUEING
Class-map: VOICE-QUEUEING (match-all)
1558937 packets, 620400570 bytes
30 second offered rate 797000 bps, drop rate 19000 bps
Match: dscp ef (46)
Priority: 20% (7700 kbps), burst bytes 192500, b/w exceed drops: 22677
VoIP facing interface (inbound marking)
show policy-map interface Gi0/0/2 | s VOICE
Class-map: VOICE (match-all)
1719737 packets, 640016991 bytes
30 second offered rate 1223000 bps, drop rate 0000 bps
Match: access-group name VOICE_ACL
QoS Set
dscp ef
Packets marked 1721038
I know that those statistics are 30 seconds average, but even though the offered rate is ~800kbps which is much less than 7.7mbps to have drops.
Does anyone have an idea what could be causing that drops into the priority queue?
Regards,
Plamen
