Re: Tc

From: Petr Lapukhov (petr@internetworkexpert.com)
Date: Fri Sep 26 2008 - 04:38:57 ART

Ali,
The "Tc" option has no use with Frame-Relay Traffic Shaping. However, it
comes to play with Frame-Relay Traffic Policing, when you set input CIR to
*zero*. This is a special case of oversubscription, where you dont guarantee
user any bandwidth (CIR) but only support the peak rate (PIR, defined by
Be/Tc value). Since CIR=0 and Bc=0 the Tc could not be calculated based on
the committed burst size. Therefore, you need an expliciti Tc interval value
to define PIR (PIR=Be/Tc in this particular case). Here is an example from
our new v5 workbook:

map-class frame-relay ZERO_CIR
 frame-relay cir in 0
 frame-relay bc in 0
 frame-relay be in 16000
 frame-relay tc 125
!
interface Serial1/3
 encapsulation frame-relay
 clock rate 128000
 frame-relay interface-dlci 231 switched
   class FROM_R2
 frame-relay intf-type dce
 frame-relay policing

Note that it only works on switched PVCs. You can read more about the FRTP
here:

http://www.cisco.com/en/US/docs/ios/12_0s/feature/guide/frtp_gsr.html 

-- 
Petr Lapukhov, CCIE #16379 (R&S/Security/SP/Voice)
petr@internetworkexpert.com

Internetwork Expert, Inc.
http://www.InternetworkExpert.com
Toll Free: 877-224-8987
Outside US: 775-826-4344

2008/9/26 Ali Moussaoui <mousawi.ali@gmail.com>

> Hello,
> Since Tc is calculated from cir n bc in frts then am wondering wats da use
> of da frame-relay tc option?
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html

Blogs and organic groups at http://www.ccie.net

This archive was generated by hypermail 2.1.4 : Sat Oct 04 2008 - 09:26:19 ART