06-01-2008 11:42 AM - edited 03-05-2019 11:21 PM
hi all, i took this example from wendell odom exam cert
map-class frame-relay shape-all-64
frame-relay traffic-shape 64000
now it was written in description that bc was calculation using bc = tc * cir where tc defaults to 125 ms, in which case bc should be 8000, but in the result of show traffic-shape, under "sustain bits/int" the value is 64000 !!! why is this so ? i have checked on a real router and its also giving me the same value, dont u think its strange ??
kindly tell me wat i am missing here
06-01-2008 05:21 PM
The 64kbps is the shaping rate. 8kbps is the Bc. With a Tc of 125ms, there are eight intervals per second, which comes out to 8kbps per interval x 8 intervals or 64kbps.
06-01-2008 06:36 PM
hi slman, but in normal CB shaping, if i only define shape average 64000, then under "sustain bits/int" showed 8000, now as the heading suggest sustain bits per "interval" then i think i should show 8000, why is it showing 64000 ?
06-01-2008 10:31 PM
I am afraid to see "frame-relay traffic-shape" command under map-class configuration. There is no specific command like this. Which exact command did you issue? Can you please give the configuration and "sh traffic-shape" command outputs.
Regards...
-Ashok.
06-02-2008 06:59 AM
There are some errors in the certification documentation. I think the command should be:
frame-relay traffic-rate 64000 64000
There is no such command as:
frame-relay traffic-shape
06-02-2008 07:19 AM
You could shape from within a map-class, which would give you the Bc=8kbps with a Tc of 125ms (the default in this case). This method provides more flexibility in tuning the shaping parameters.
map-class frame-relay SHAPE_ALL
frame-relay cir 64000
frame-relay bc 8000
interface serial0/0
frame-class SHAPE_ALL
frame-relay traffic-shaping
06-03-2008 12:06 AM
hi all, sorry for mistyping, the command was surely frame-relay traffic-rate 64000 64000 and here is the output
R1#sh traffic-shape
Interface Se0/0
Access Target Byte Sustain Excess Interval Increment Adapt
VC List Rate Limit bits/int bits/int (ms) (bytes) Active
102 64000 1000 64000 0 125 1000 -
(i think its not properly alligned but still) kindly see under sustain bits its giving 64000 !! why ? plz i am not looking for alternate solutions, i know how to do it from normal CB shaping, all i am looking for is the meaning of why its 64000 written under sustain bits ??? why it isnt 8000 ?
see if i use normal CB shaping using this config
policy-map shape-all
class class-default
shape average 64000
int se 0/0
service-policy output shape-all
now if i issue command
show policy-map int se 0/0
then under sustain bits its written 8000 !!!! all other values are same, so i am asking why in FRTS its showing me 64000 ? where it should be 8000 dont u guys think ?, i mean no disrespect to any1 i am very thankful to those who replied but i am not looking for a alternate solution, i want to know why the output is showing 64000 and not 8000 ?
Kindly guide me in this
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