[c-nsp] random-detect drop counts

[Tony]

Hi all,

I'm testing with the "random-detect" command to use WRED for congestion avoidance.

I've enabled it under "class-default" in a child policy, where the parent policy is a shaper to shape traffic to the purchased speed of the tail link.

My question is in regard to the counting of drops by the policy. Looking at the output below the total drop count for class-default is 4009. If you then look at the drop counts for both random drop (1622) and tail drop (219) the sum of these does NOT equal the total drop count (it's less than half).

So if a packet is not getting dropped by either random or tail drop, then how/where is it getting dropped ?  

There are other classes in the policy-map with some reserved bandwidth and they aren't showing any drops (but I didn't enable WRED on them either).


If it matters HW/SW is 7609 with SIP-400 & GigE-SPA running 12.2(33)SRD4.




        Class-map: class-default (match-any)
          1125330 packets, 1223563563 bytes
          30 second offered rate 2833000 bps, drop rate 2000 bps
          Match: any

          queue limit 360 packets
          (queue depth/total drops/no-buffer drops) 0/4009/0
          (pkts output/bytes output) 1122027/1219085597
            Exp-weight-constant: 9 (1/512)
            Mean queue depth: 8 packets
            class       Transmitted         Random drop      Tail drop          Minimum        Maximum     Mark
                    pkts/bytes            pkts/bytes       pkts/bytes          thresh         thresh     prob

            0         1122025/1219085373   1622/2049685      219/286707            90           180  1/10
            1               0/0               0/0              0/0                101           180  1/10
            2               0/0               0/0              0/0                112           180  1/10
            3               0/0               0/0              0/0                123           180  1/10
            4               0/0               0/0              0/0                135           180  1/10
            5               0/0               0/0              0/0                146           180  1/10
            6               0/0               0/0              0/0                157           180  1/10
            7               0/0               0/0              0/0                168           180  1/10




Thanks,
Tony.