Hi all,
I have an issue and i hope somebody can help.
I have configured a priority queue on my 2911 to prioritize ICMP traffic in its own queue of 1000 kbps and all other traffic shares the remaining 100% of the bandwidth. My WAN interface is hardwired to 10mbps full duplex and seemingly when i do the "show policy-map interface gi0/0" everything seems to check out but when i max out my internet connection downloading multiple test files the ping latency is always a standard 67-80 ms but as soon as i stop my downloads its around 13ms solid. I'm using NBAR to identify the ICMP traffic and this seems to work. I was under the impression that LLQ guaranteed latency as well as bandwidth?
Can anyone see anything wrong with my config or offer an explanation why my priority queue traffic is suffering high latency issues when downloading/under-load. I was using this as a test to implement on VoiP traffic but it does not seem to work :/
class-map match-any icmp-class
match protocol icmp
policy-map PMAP_LLQ
class icmp-class
priority 1000
class class-default
bandwidth remaining 100
fair-queue
interface gi0/0 <--WAN
service-policy output PMAP_LLQ
interface gi0/2 <--LAN
ip nbar protocol-discovery
Router Output for troubleshooting
Router#show policy-map interface gi0/0
GigabitEthernet0/0
Service-policy output: PMAP_LLQ
queue stats for all priority classes:
queue limit 64 packets
(queue depth/total drops/no-buffer drops) 0/0/0
(pkts output/bytes output) 301/236567
Class-map: icmp-class (match-any)
301 packets, 236567 bytes
5 minute offered rate 16000 bps, drop rate 0 bps
Match: protocol icmp
301 packets, 236567 bytes
5 minute rate 16000 bps
Priority: 1000 kbps, burst bytes 25000, b/w exceed drops: 0
Class-map: class-default (match-any)
35118 packets, 1898687 bytes
5 minute offered rate 57000 bps, drop rate 0 bps
Match: any
Queueing
queue limit 64 packets
(queue depth/total drops/no-buffer drops/flowdrops) 0/0/0/0
(pkts output/bytes output) 35118/1898687
bandwidth remaining 100% (9000 kbps)
Fair-queue: per-flow queue limit 16
Router#
