From: Jongsoo kim (bstrt2002@gmail.com)
Date: Mon Mar 28 2005 - 15:01:42 GMT-3
Dillon
Let's say you have to F/R HUb and 12 Spokes using 1 T1.
If F/R hub need to send 128Kbps of Multicast stream and has "
broadcast" key word on PVC, then it will send 12 x 128Kbps = 1536Kbps,
which will make T1 100% congested...
Just my thought.
Regards
Jongsoo
On Mon, 28 Mar 2005 18:36:28 +0200, Alexander Arsenyev (GU/ETL)
<alexander.arsenyev@ericsson.com> wrote:
> Useless broadcasts/multicasts consume bandwidth. FR multipoint interface may have many PVCs but all these PVCs have to share the same physical line.
> Of course, replicating broadcast/multicast packets also consumes memory and CPU cycles.
> Bottom line is - make sure that broadcast/multicast packets are sent only on those PVCs where necessary and that's my understanding of the function of the "broadcast" keyword.
> HTH,
> Cheers
> Alex
>
> -----Original Message-----
> From: Dillon Yang [mailto:gzdillon@hotmail.com]
> Sent: 28 March 2005 16:52
> To: Alexander Arsenyev (GU/ETL)
> Cc: Group Study
> Subject: Re: NBMA in real word
>
> Hi, Alexander:
>
> Thanks.
> But I want to know some real situation that the "broadcast" is harmful. Say, the cisco is a vendor that will not put a useless keyword into the IOS. If the command without "broadcast" has no specific usage, then it should be merged with the command with "broadcast" into a SINGLE command.
> Any advice?
>
> TIA
> dillon
>
> ----- Original Message -----
> From: "Alexander Arsenyev (GU/ETL)" <alexander.arsenyev@ericsson.com>
> To: "'Dillon Yang'" <gzdillon@hotmail.com>; <ccielab@groupstudy.com>
> Sent: Monday, March 28, 2005 11:19 PM
> Subject: RE: NBMA in real word
>
> > My 2 pence:
> > 1) Good practice is NOT to map spoke-to-spoke with "broadcast" keyword, broadcasts from one spoke to another won't be propagated by hub anyway.
> > 2) "broadcast" keyword also applies to multicast. Therefore, if Your task asks You to propagate mcast to a subset of spokes then map with "broadcast" only relevant (multicast-enabled) spokes.
> > HTH,
> > Cheers
> > Alex
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]
> > Sent: 28 March 2005 15:07
> > To: Group Study
> > Subject: NBMA in real word
> >
> >
> > Hi, group:
> >
> > Normally, the command "frame-relay map ip xxx broad" works. But I never meet a situation that the FR link can not allow broadcast, anybody can explain what case the "broadcast" can not be allowed?
> >
> > TIA
> > dillon
> >
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