FRTS revisited

From: Nick Shah (nshah@xxxxxxxxxxxxxx)
Date: Sun May 12 2002 - 22:11:40 GMT-3


   
Guys, Hope if someone can shed some light on this...

frame-relay traffic-rate can be used as a subset of specifying CIR/BE/BC
parameters (in a map class). However different (bizarre !!) results are
obtained by using it in lieu.
for eg.

map-class frame-relay MPCLASS
frame-relay traffic-rate 64000 72000 (CIR, & PIR peak rate, peak rate has to
be CIR+EIR)

RouterA#sh traffic-shape

Interface Se0
       Access Target Byte Sustain Excess Interval Increment Adapt
VC List Rate Limit bits/int bits/int (ms) (bytes)
Active
110 64000 2000 64000 8000 125 1000 -
120 64000 2000 64000 8000 125 1000 -
130 64000 2000 64000 8000 125 1000 -

However ...

map-class frame-relay MPCLASS
 frame-relay cir 64000
 frame-relay bc 8000
 frame-relay be 8000

RouterA#sh traffic-shape

Interface Se0
       Access Target Byte Sustain Excess Interval Increment Adapt
VC List Rate Limit bits/int bits/int (ms) (bytes)
Active
110 64000 2000 8000 8000 125 1000 -
120 64000 2000 8000 8000 125 1000 -
130 64000 2000 8000 8000 125 1000 -
RouterA#

However the important point to see is that the byte-limit still remains the
same, but the Sustain bits/int (BC) changes. I know that BC = CIR/Tc (CIR
per time interval), so does this mean that it will *burst* upto twice its
capacity (64K ---- > 128K).

Has anyone noticed this.. I remember John Neiberger pointing something
similar out a few months ago, but I couldnt find any followup mail on that
...

Nick

Nick



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