Re: Interesting FRTS Behavior Driving Me Mad

Joe

That's an interesting observation. I've never noticed this behavior before
either. It looks like the maximum byte-limit is 10000. I'm guessing that
when you give a Bc value that forces the byte-limit to over 10000 per
interval, it recalculates the Bc as well as the Tc. I wonder what purpose
this serves.

--Here are the values I used in the map class

map-class frame-relay FRTS
 frame-relay cir 1000000
 frame-relay bc 125000

R2# sh traffic-shape

Interface Se1/0
       Access Target Byte Sustain Excess Interval Increment Adapt
VC List Rate Limit bits/int bits/int (ms) (bytes)
Active

Interface Se1/0.23
       Access Target Byte Sustain Excess Interval Increment Adapt
VC List Rate Limit bits/int bits/int (ms) (bytes)
Active
203 1000000 7875 125000 0 63 7875 -

Notice that 7875*8 = 63000bits

-Mike McFarlin
router.genie_at_gmail.com

On Mon, Nov 30, 2009 at 12:07 AM, Joe Astorino <jastorino_at_ipexpert.com>wrote:

> Oh yeah and the essential: two different IOS , two different platforms...
>
> R2(config-map-class)#do sh ver | i 12.4
> Cisco IOS Software, 3800 Software (C3825-ADVENTERPRISEK9-M), Version
> 12.4(24)T1, RELEASE SOFTWARE (fc3)
>
>
> R5(config-if)#do sh ver | i 12.4
> Cisco IOS Software, 3600 Software (C3640-JK9O3S-M), Version 12.4(13a),
> RELEASE SOFTWARE (fc1)
>
>
>
>
> On Mon, Nov 30, 2009 at 3:02 AM, Joe Astorino <jastorino_at_ipexpert.com
> >wrote:
>
> > Has anybody seen anything like this before? It seems the formula for how
> > my router is calculating Tc dynamically changes based on the given value
> of
> > Bc which I have not read about in any book or cisco doc as of yet.
> >
> >
> > R2(config-map-class)#do sh run int s0/1/0 | i frame-relay
> > encapsulation frame-relay
> > frame-relay class foo
> > frame-relay traffic-shaping
> > frame-relay map ip 100.100.100.5 205 broadcast
> > no frame-relay inverse-arp
> >
> > R2(config-map-class)#do sh run | beg map-class
> > map-class frame-relay foo
> > frame-relay cir 768000
> > frame-relay bc 80007
> >
> > With this setup, I expect the long standing formula Tc = Bc / CIR to hold
> > true. Therefore Tc should be equal to 80007 / 768000 = 0.10417578125
> > seconds = 104ms rounded down and indeed it is
> >
> > R2(config-map-class)#do sh traffic
> >
> > Interface Se0/1/0
> > Access Target Byte Sustain Excess Interval Increment
> > Adapt
> > VC List Rate Limit bits/int bits/int (ms) (bytes)
> > Active
> > 205 768000 10000 80007 0 104 9984 -
> >
> >
> > However, as soon as I cross the Bc boundary of 80007 and set it to 80008
> my
> > Tc is changed to what appears to be (Bc / CIR) / 2 !!! WTF?
> >
> > R2(config-map-class)#do sh traffic
> >
> > Interface Se0/1/0
> > Access Target Byte Sustain Excess Interval Increment
> > Adapt
> > VC List Rate Limit bits/int bits/int (ms) (bytes)
> > Active
> > 205 768000 5000 80008 0 52 4992 -
> >
> > As you can see the Tc has been set to 52 ms which just so happens to be
> 1/2
> > of the previous value of 104ms. Any clues?
> >
> >
> >
> >
> >
> > --
> > Regards,
> >
> > Joe Astorino CCIE #24347 (R&S)
> > Sr. Technical Instructor - IPexpert
> > Mailto: jastorino_at_ipexpert.com
> > Telephone: +1.810.326.1444
> > Live Assistance, Please visit: www.ipexpert.com/chat
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>
> --
> Regards,
>
> Joe Astorino CCIE #24347 (R&S)
> Sr. Technical Instructor - IPexpert
> Mailto: jastorino_at_ipexpert.com
> Telephone: +1.810.326.1444
> Live Assistance, Please visit: www.ipexpert.com/chat
> eFax: +1.810.454.0130
>
> IPexpert is a premier provider of Classroom and Self-Study Cisco CCNA (R&S,
> Voice & Security), CCNP, CCVP, CCSP and CCIE (R&S, Voice, Security &
> Service
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-- 
Mike McFarlin
router.genie_at_gmail.com
Blogs and organic groups at http://www.ccie.net