Does peering at an ATM MAE require a router that does ABR?

Alex alex at nac.net
Thu Mar 1 22:11:39 UTC 2001



Yes. They are still there.

They are both ABR services. The 'guaranteed' as they call is, has the PCR
at 2x MCR.

The 'best-effort' is MCR of 100 cps, PCR being somewhere around 1/2 port
speed.




On Thu, 1 Mar 2001, Steve Feldman wrote:

> 
> On Thu, Mar 01, 2001 at 01:36:03PM -0800, Kevin Oberman wrote:
> > 
> > In the past, the MAE ATM switches ran ABR where you specified the MCR
> > and traffic was policed at a PCR of 2xMCR, although almost no one at
> > the MAEs actually used ABR on their connections. Almost everyone used
> > VBR-nrt and many did not even realize that the use of ABR could have
> > been beneficial.
> 
> To be even more precise, MAE-ATM runs ABR 
> nternally, but didn't speak the protocol
> over the UNI to the routers.
> 
> In this mode, the switches being used would
> emulate VBR-nrt but actually do some input
> buffering and shaping to smooth out bursts.
> This came in very handy for older router interfaces
> which couldn't shape on their own.
> 
> I never had an ABR-speaking router to try it with.
> 
> > With "best effort" PVCs, this really becomes moot although these are
> > still technically ABR.
> 
> Agreed, though I'm not famiiliar with details of the
> "best effort" service.  And I'm pretty sure the reserved
> and policed service is still there for folks who still
> want to use it.
> 
> 	Steve
> 	(former target-carrier)
> 
> 





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