04-19-2009 01:42 PM - edited 03-06-2019 05:16 AM
Hi Group,
I am having an issue with applying nested QoS policy to an interface and not seeing the packets placed in the strict priority queue.
Here is my configuration:
class-map match-any WAN_Egress_Cisco_Voice_Signaling
match ip dscp cs3
class-map match-all WAN_Egress_Scavenger
match ip dscp cs1
class-map match-all WAN_Egress_Bulk_Data
match ip dscp af11 af12
class-map match-all WAN_Egress_Business_Applications
match ip dscp cs2 cs3 af31 cs6
class-map match-any WAN_Egress_VTC_Video_Conferencing
match ip dscp af42
class-map match-any WAN_Egress_VoIP_Media
match ip rtp 16384 16383
match ip dscp ef
!
policy-map WAN_EGRESS_POLICY
class WAN_Egress_VoIP_Media
priority percent 15
class WAN_Egress_VTC_Video_Conferencing
bandwidth remaining percent 20
class WAN_Egress_Business_Applications
bandwidth remaining percent 35
random-detect
class WAN_Egress_Bulk_Data
bandwidth remaining percent 14
class WAN_Egress_Scavenger
bandwidth remaining percent 1
class class-default
bandwidth remaining percent 30
random-detect
!
policy-map WAN_EGRESS_POLICY_T1
class class-default
shape average 1544000
service-policy WAN_EGRESS_POLICY
!
interface s2/0
ip address 10.0.0.1 255.255.255.0
service-policy output WAN_EGRESS_POLICY_T1
I used extended ping with ToS of 0xb8 to generated EF traffic. I see the EF packets matching the VoIP Media class map but not to the priority queue (as seen in the output from "show policy-map int s2/0" command):
Service-policy output: WAN_EGRESS_POLICY_T1
Class-map: class-default (match-any)
1009 packets, 104126 bytes
5 minute offered rate 8000 bps, drop rate 0 bps
Match: any
Traffic Shaping
Target/Average Byte Sustain Excess Interval Increment
Rate Limit bits/int bits/int (ms) (bytes)
1544000/1544000 9650 38600 38600 25 4825
Adapt Queue Packets Bytes Packets Bytes Shaping
Active Depth Delayed Delayed Active
- 0 1000 104000 0 0 no
Service-policy : WAN_EGRESS_POLICY
Class-map: WAN_Egress_VoIP_Media(match-any)
1000 packets, 104000 bytes
5 minute offered rate 8000 bps, drop rate 0 bps
Match: ip rtp 16384 16383
0 packets, 0 bytes
5 minute rate 0 bps
Match: ip dscp ef
1000 packets, 104000 bytes
5 minute rate 8000 bps
Match: ip dscp cs5
0 packets, 0 bytes
5 minute rate 0 bps
Queueing
Strict Priority
Output Queue: Conversation 72
Bandwidth 15 (%)
(pkts matched/bytes matched) 0/0
(total drops/bytes drops) 0/0
Any help regarding this would be highly appreciated. Thanks much!
- Kashif
04-19-2009 02:57 PM
hi
your problem with the class maps
change all class maps that has multiple matching such as
match ip dscp cs2 cs3 af31 cs6
change the class map matching
from match-all TO match-any
good luck
if helpful rate
04-20-2009 02:28 AM
Looks alright to me.
You might misunderstand the stats. If your concern is the zero matches for the PQ, that can indicate there wasn't enough congestion for that class's matched packets to be queued. It's common to see this stat, on any class that shows it, less than the class match stats. This might be confirmed by the fact your parent shaper shows zero delayed packets. (Only when the shaper delays packet should packets be queued into the child policy's queues.)
PS:
BTW, what kind of serial link is it that you needed to shape it to 1.5 Mbps?
04-20-2009 05:59 PM
Thanks much Joseph. I suspected that this is what the case is. The original policy is for a DS3 link on a customer's 7206VXR but I am simulating this for a serial interface in the lab environment. Personally, I think we don't need to shape a DS3 link unless we want it to be under utilized. What do you think?
Perhaps I should generated large datagrams on this 1.5Mbps link to saturate it and lower down the traffic shaping limit to see the packets in the strict priority queue. I will keep you posted if I get that working.
Marwan - Thanks for pointing out the match-any thing to. It would be a good idea for that class-map. However, the problem I suspected I was seeing was with the VoIP_Media class with already has match-any statement.
Thanks again for the replies!
- Kashif
04-21-2009 03:28 AM
As to seeing LLQ activate in a test situtation, I've found an easy method to do so is to use some kind of traffic generator to fill bandwidth with "background" traffic. I've also used your idea of setting a shaper slower to see the effect too.
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