legacy rtp reservation

I'm having some trouble seeing results after configuring legacy RTP reserve queueing. The simulated rtp traffic from R6 to R5

 has an IPP of 1 while the web traffic from R1 to SW4 has a cos of 7. I get the same weights after configuring ip rtp reserve as show below

interface Serial0/1/0
 bandwidth 128
 ip address
 ip mtu 156
 ip rip advertise 10
 tx-ring-limit 1
 tx-queue-limit 1
 fair-queue 64 32 1
 max-reserved-bandwidth 100
 ip rtp reserve 16384 16383 128

Rack1R4#sh queueing int s0/1/0
Interface Serial0/1/0 queueing strategy: fair
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: weighted fair
  Output queue: 30/1000/64/0 (size/max total/threshold/drops)
     Conversations  2/3/32 (active/max active/max total)
     Reserved Conversations 1/1 (allocated/max allocated)
     Available Bandwidth 0 kilobits/sec

  (depth/weight/total drops/no-buffer drops/interleaves) 26/4048/0/0/0
  Conversation 7, linktype: ip, length: 36
  source:, destination:, id: 0x1D13, ttl: 254, prot: 6

  (depth/weight/total drops/no-buffer drops/interleaves) 4/16192/0/0/0
  Conversation 19, linktype: ip, length: 160
  source:, destination:, id: 0x0229, ttl: 254,
  TOS: 32 prot: 17, source port 56694, destination port 16385


I'm assuming it isn't hitting the reserve queue based on the conversation number of 19. It should be 41 based on the dynamic+link queues.

Rack1R4#show queueing fair
Current fair queue configuration:

  Interface           Discard    Dynamic  Reserved  Link    Priority
                      threshold  queues   queues    queues  queues
  Serial0/1/0         64         32       1         8       1


  • Hi, eventhough I am writing almost three years too late, but this problem description was exactly the same like I had miself few minutes ago and here was no solution provided. The thing is that legacy RTP reserve option assigns flow to reserved queue only if port number is even - same like myself you had UDP traffic to 16385 port. I f you fix it to 16384 it would work properly.
    Hope it helps to anyone in the future!


Sign In or Register to comment.