The DE bit is significant only on the frame cloud.
yes, this can be transferred from carrier to carrier. for example, if you
have a frame circuit between Portland OR and San Diego, CA you are crossing
LATA boundaries, and a RBOC boundary, so must use at least two carriers. In
that case, your CIR is significant end to end across the frame clouds of two
carriers.
in the case of an internet connection, one would hope that the ISP pop is in
the same town, and that they use a different carrier onto the internet
backbone, so there would be no transfer of the DE bit onto any internet
backbone.
I should clarify by saying that the CIR is significant only to your end to
end circuit. The termination of that circuit into another router ends the
layer two framing. Even if the data were forwarded by that router onto
another frame circuit from the same carrier, a new layer two frame would
still be built, and no DE bit would have been set.
Zero CIR is not necessarily a bad thing. Lot's of companies do things like
that to minimize their costs. OTOH, I thought most carriers these days were
not selling zero CIR, for that same reason.
Yes, your router will try to pump out a T1 worth of data if it has it. In
general, though, chances are good that you are not attempting to fully
utilize the line. It is only when your carrier frame cloud is seeing more
traffic than it can handle that frames with the DE bit are dropped.
HTH
Chuck
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of
Mike Mandulak
Sent: Wednesday, August 08, 2001 4:33 AM
To: [EMAIL PROTECTED]
Subject: Fw: DE bits [7:15210]
----- Original Message -----
From: "Mike Mandulak"
To: "Chuck Larrieu"
Sent: Wednesday, August 08, 2001 6:31 AM
Subject: Re: DE bits [7:15210]
> That's what I thought, when I confronted them on it they basically said
that
> since I have a full T1 all traffic will go through. But my Q is if it has
DE
> set through to their CO, does the DE bit stay set as it traverses the
> internet and thru other providers? Even if it get transformed into say ATM
> frames or whatever on it's way? I think they are feeding me a line...
>
> ----- Original Message -----
> From: "Chuck Larrieu"
> To: "Mike Mandulak" ;
> Sent: Wednesday, August 08, 2001 1:04 AM
> Subject: RE: DE bits [7:15210]
>
>
> > nope. with a 0 CIR anything greater than 0 is DE.
> >
> > your telco is not guaranteeing that they will ever pass any of your
> traffic.
> >
> > Chuck
> >
> > -----Original Message-----
> > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of
> > Mike Mandulak
> > Sent: Tuesday, August 07, 2001 9:17 PM
> > To: [EMAIL PROTECTED]
> > Subject: DE bits [7:15210]
> >
> >
> > Do discard Eligible bits (DE) get set on lines that are full T1's? The
> > circuit I'm looking at is a full T1 to one of my internet providers and
> when
> > looking at the frame stats (using cisco LMI) I see that that the cir is
> set
> > to zero which would mean that all frames leave my site with the DE bit
> set.
> > Am I misunderstanding this?
> >
> > MikeM
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=15278&t=15210
--------------------------------------------------
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
