FRTS Default Bc value

Hello,
I ran into an output of a FRTS show command that contradicts what I know so
far and figure ask the experts to see where is the disconnect.

Based on what I know and the Enterprise QoS SRND, the Bc value by default
should be set to Bc= CIR/8.
If I configure traffic shaping on an FR interface I see that bc on my DCLI
205 is set to 7000 bits (which is correct) :

Rack1R2#sh frame-relay pvc 205

PVC Statistics for interface Serial0/0/0 (Frame Relay DTE)

DLCI = 205, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0/0/0

  input pkts 275289 output pkts 125138 in bytes 20715768
  out bytes 12816805 dropped pkts 0 in pkts dropped 0
  out pkts dropped 0 out bytes dropped 0
  in FECN pkts 0 in BECN pkts 0 out FECN pkts 0
  out BECN pkts 0 in DE pkts 0 out DE pkts 0
  out bcast pkts 13544 out bcast bytes 1013448
  5 minute input rate 1000 bits/sec, 1 packets/sec
  5 minute output rate 1000 bits/sec, 1 packets/sec
  pvc create time 2d10h, last time pvc status changed 00:01:48
  cir 56000 * bc 7000 * be 0 byte limit 875 interval 125
<-------------------bc 7000
  mincir 28000 byte increment 875 Adaptive Shaping none
  pkts 135 bytes 15363 pkts delayed 0 bytes delayed 0
  shaping inactive
  traffic shaping drops 0
  Queueing strategy: fifo
  Output queue 0/40, 0 drop, 0 dequeued

Now if I apply a map-class with cir of 256,000 I don't see what I would
expect, which is the Bc to be set to 32,000 but rather the Bc is set to
256,000. This does not make much sense to me especially that when I look at
show traffic-shape the Tc is still set to .125sec.

map-class frame-relay FRTS
 frame-relay cir 256000

interface Serial0/0/0
 ip address 136.1.245.2 255.255.255.0
 encapsulation frame-relay
 no fair-queue
 frame-relay class FRTS
 frame-relay traffic-shaping
 frame-relay map ip 136.1.245.5 205 broadcast
 no frame-relay inverse-arp
end

Rack1R2#sh frame-relay pvc 205

PVC Statistics for interface Serial0/0/0 (Frame Relay DTE)

DLCI = 205, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0/0/0

  input pkts 107 output pkts 0 in bytes 9918
  out bytes 0 dropped pkts 0 in pkts dropped 0
  out pkts dropped 0 out bytes dropped 0
  in FECN pkts 0 in BECN pkts 0 out FECN pkts 0
  out BECN pkts 0 in DE pkts 0 out DE pkts 0
  out bcast pkts 0 out bcast bytes 0
  5 minute input rate 1000 bits/sec, 1 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
  pvc create time 00:01:04, last time pvc status changed 00:01:04
  cir 256000 *bc 256000* be 0 byte limit 4000 interval 125
<<--------------bc 256,000
  mincir 128000 byte increment 4000 Adaptive Shaping none
  pkts 0 bytes 0 pkts delayed 0 bytes delayed 0
  shaping inactive
  traffic shaping drops 0
  Queueing strategy: fifo
  Output queue 0/40, 0 drop, 0 dequeued

Does anyone have any idea where the disconnect is?

Thank you,

Tom

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Received on Sun Apr 01 2012 - 21:51:21 ART