Re: [nsp] telco SCR/PCR and Cisco kbps

From: sthaug@nethelp.no
Date: Sat May 12 2001 - 06:33:32 EDT


> >I'm afraid this is incorrect. The Cisco kbps value is converted to cells
> >using 53 bytes per cell, not 48. You can verify this for yourself by doing
>
> Ah yes, BUT if you examine his configuration, you will see he is using
> an older generation IOS method of ATM provisioning:
>
> = = = = = = = = = = =
>
> interface ATM1/0.37 point-to-point
> description 1536 PVC to POP
> bandwidth 1536
> ip address 1.2.3.4 255.255.255.252
> no ip directed-broadcast
> atm pvc 1 1 37 aal5snap 1536 1536 100
> !
> = = = = = = = = = = =
>
> When using this method, traffic shaping rates are with reference to
> 48 byte cell payload.

I just tried this on a router with 12.1(5)T7. The old method still works,
and it uses 53 byte per cell:

 atm pvc 1 0 110 aal5snap 1536 1536 100

gives the following debug message:

May 12 12:30:20: VBR: pcr 3622, scr 3622, mbs 100

Steinar Haug, Nethelp consulting, sthaug@nethelp.no



This archive was generated by hypermail 2b29 : Sun Aug 04 2002 - 04:12:37 EDT