Re: Differences in "Show Policy-Map Interface" Output

bssmith10 · ‎12-29-2010

I have been used to the easy to understand output of the "show policy-map interface X" command, and now Cisco decides to change the look of the output just a bit in 15.x code which is not so easy to understand. More specifically the output of the command in referrence to the priority queue. Two examples, the first from 12.4 code, the second from 15.1 code. In the first example it is easy to see/understand there are drops in the queue and how much. In the second example it is not so easy to see/understand. Did I have drops, and if so how much? I see "b/w exceed drops: 60". What does that mean? Why the change? Thanks for the help in understanding the new output.

sh policy-map int s1/7:0
Serial1/7:0

Service-policy output: UDN-EDGE

    Class-map: VOICE (match-all)
      11491190 packets, 3430393368 bytes
      5 minute offered rate 28000 bps, drop rate 0 bps
      Match: dscp ef (46)
      Queueing
        Strict Priority
        Output Queue: Conversation 264
        Bandwidth 10 (%)
        Bandwidth 153 (kbps) Burst 3825 (Bytes)
        (pkts matched/bytes matched) 1747144/495196236
        (total drops/bytes drops) 132302/39625848

sh policy-map int
Serial0/0/0:0

Service-policy output: UDN-EDGE

    queue stats for all priority classes:

      queue limit 64 packets
      (queue depth/total drops/no-buffer drops) 0/0/0
      (pkts output/bytes output) 1105445/346607027

    Class-map: VOICE (match-all)
      1105505 packets, 346626467 bytes
      5 minute offered rate 27000 bps, drop rate 0 bps
      Match: dscp ef (46)
      Priority: 10% (153 kbps), burst bytes 3800, b/w exceed drops: 60

Peter Paluch · ‎12-29-2010

Hello,

I cannot speak for Cisco to explain why the output format has changed, but the 15.1 style of output for your VOICE class seems actually logical to me. If you specify a strict priority class in a CBWFQ construct, that class is both guaranteed and policed to the specified bandwidth. The "b/w" stands for bandwidth, and the "b/w exceed drops: 60" means that there are 60 dropped packets due to the policing - they would otherwise exceed the guaranteed bandwidth for the given class.

Just my two cents

Best regards,

Peter

bssmith10 · ‎12-30-2010

Peter, thank you for your reply.

I fully understand the function of the priority queue, which is why I want to see more than just "b/w exceed drops:". At least with earlier code you also saw total bytes dropped. I know this isn't a forum for complaints or opinions so I will let it go. You did provide an answer as to what "b//w exceed drops" was showing, but I am still a bit skeptical about that answer, and I say that because where this router is located at (second hop out towards three locations that are receiving voice traffic) and the testing we are doing of intentionally flooding the priority queue, I would have estimated a much higher amount of drops.

Another question concerning the new output; if the "b/w exceed drops" is supposed to show dropped packets, then why does the line (queue depth/total drops/no-buffer drops) 0/0/0 show zero total drops? Is this a counter for something else?