Re: FR Tidbit [was: 56k modems/frame/ptp revisited (LONG)]

[Dan Jones <danjones () bbn com>]

Scott,

        I'm curious.  Is your assertion that "CIR is guaranteed only under
"normal" conditions" based on the Frame Relay spec or a paticular vendor(s)
implementation?  I ask because I have been in that very debate for some
time (usually with a FR vendor justifying lousey performance).

        My tendancy is to take the "Comitted" in CIR literally.  It's my
understanding that the FR congestion management routines (at least the
Stratacom one - Foresight?) will only back off bursty PVC to the point
where it's <= CIR.  The implication then is that you'll always get at least
CIR - which makes sense since that's what you're paying for. 

Dan 



At 08:45 AM 9/1/98 -1000, scott w wrote:
> On Tue, 1 Sep 1998, Scott, Dan wrote:
>
> [snip]
> > line and port, but the important parameter is the committed information
rate
> > you purchase from the carrier.  Most of Sprint's frame relay business may
> [snip]
> > from 0-56kbps.  Can purchase 56kbps CIR, but it costs extra, would need
> [snip]
>
> CIR is guaranteed only under "normal" conditions.  You won't get it under
> heavy congestion.  Find out the MIR configured for your PVC.  I don't know
> if they will tell you though...
>
> scott