What the FECN?

From: David Timmons (masterdt@yahoo.com)
Date: Fri Jun 30 2006 - 12:08:55 ART


I was looking at router that had been configured and
it has me confused.

created a map-class:
map-class frame-relay bobsuruncle
 frame-relay adaptive-shaping becn
 frame-relay cir 1024000
 frame-relay bc 1280000

applied to interface:
interface Serial0.1 point-to-point
 ip address 10.64.7.6 255.255.255.252
 frame-relay class bobsuruncle
 frame-relay interface-dlci 180

Interface Se0.1
       Access Target Byte Sustain Excess
Interval Increment Adapt
VC List Rate Limit bits/int bits/int
(ms) (bytes) Active
180 1024000 10112 1280000 0 79
      10112 BECN

It looks like Cisco has overridden the Bc and used a
Bc of 80896. I base this on the calculation of the Tc
of 79ms. I would have assumed that the people that
configured really meant to do something like this

map-class frame-relay bobsuruncle
 frame-relay adaptive-shaping becn
 frame-relay cir 1024000
 frame-relay bc 128000
 frame-relay be 32000

I think this should allow us to burst to 160000 per Tc
for a total of 1280000. Do I have this right? It is
strange that Cisco accepted the Bc value. In any
event, it looks like router is getting less bandwidth
then I assumed they are allocated.



This archive was generated by hypermail 2.1.4 : Sat Jul 01 2006 - 07:57:34 ART