[c-nsp] Input queue flushes and drops

[Rodney Dunn]

On 2/26/10 1:57 AM, Javi in AUS wrote:
> Gents,
>
> We have a WAN facing Cisco 3845 which is showing the numbers below on it's
> Gi0/1 interface:
>
>   Input queue: 0/75/9/71805 (size/max/drops/flushes); Total output drops:
> 714432
>

Turn off SPD:

config t
no spd enable
end



>
> Of course, these counters are increasing and we have a bunch of users at the
> other side of the link complaining about poor VoIP performance (they hear
> us intermittently although we can hear them Ok).
> CEF is enabled globaly, input queue is set to default (75).
>
> GigabitEthernet0/1 is up, line protocol is up
>    Hardware is BCM1125 Internal MAC, address is 001b.d37d.f8a2 (bia
> 001b.d37d.f8a2)
>    Internet address is 10.83.2.17/30
>    MTU 1500 bytes, BW 20000 Kbit/sec, DLY 100 usec,
>       reliability 255/255, txload 11/255, rxload 10/255
>    Encapsulation ARPA, loopback not set
>    Keepalive set (10 sec)
>    Full-duplex, 100Mb/s, media type is RJ45
>    output flow-control is XON, input flow-control is XON
>    ARP type: ARPA, ARP Timeout 04:00:00
>    Last input 00:00:00, output 00:00:00, output hang never
>    Last clearing of "show interface" counters 3w3d
>    Input queue: 0/75/9/71805 (size/max/drops/flushes); Total output drops:
> 714432
>    Queueing strategy: Class-based queueing
>    Output queue: 0/1000/0 (size/max total/drops)
>    30 second input rate 848000 bits/sec, 634 packets/sec
>    30 second output rate 874000 bits/sec, 604 packets/sec
>       1146444284 packets input, 1913512714 bytes, 0 no buffer
>       Received 1785 broadcasts, 0 runts, 0 giants, 1 throttles
>       0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
>       0 watchdog, 6993 multicast, 0 pause input
>       0 input packets with dribble condition detected
>       1121611018 packets output, 2544901813 bytes, 0 underruns
>       0 output errors, 0 collisions, 0 interface resets
>       0 unknown protocol drops
>       0 babbles, 0 late collision, 0 deferred
>       0 lost carrier, 0 no carrier, 0 pause output
>       0 output buffer failures, 0 output buffers swapped out
>
>

What is your policy doing on that interface for the output drops?

sh policy-map interface gig 0/1

What does 'sh int stat' show...the input queue is only for process 
switched traffic so you need to figure that out?

What code?...12.4(20)T and later you can do an EPC trace on the punt 
path coming in the interface to see what traffic it is.

Or try to catch the packets in 'sh buffers input-interface gig 0/1 packet'


> Should we increase the input queue size to 150,200,250, etc ? Could these
> flushed/drops be the cause of the poor VoIP performance?

Yeah..set it to the max of 4096.

Rodney

> Many thanks,
>
> P
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