Subject: Switching btw RPT and SPT in PIM-SM

From: Fethi Filali <[email-masked]>
Date: Fri, 06 Oct 2000 07:05:46 +0000

hi all,

I have the following question about PIM-SM. 

The recommended switching (btw RPT and SPT) policy in PIM-SM
specification is to initiate the switch to the SPT after receiving a
significant number of data packets during a specified time interval from
a particular source. 

I believe that this heuristic for determining when to migrate from the
RPT to the SPT, and vise versa, is far from being sufficient. 

Are there other works or links concerning the switching mechanisms in
PIM-SM.

Thanks,

--
FF

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From: Dirk Ooms <[email-masked]>
Date: Fri, 06 Oct 2000 11:00:05 +0200

> RPT to the SPT, and vise versa, is far from being sufficient.

There is no vise versa.

In practice the switch-over is made immediately (configured to a low
bitrate).  The RP only functions as a method for receivers to discover
sources.

dirk

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From: Fethi Filali <[email-masked]>
Date: Fri, 06 Oct 2000 09:11:13 +0000

> > RPT to the SPT, and vise versa, is far from being sufficient.

Yes, in the RFC there is no provision to the vise versa but I think that
it should be also possible ...
 
> bitrate).  The RP only functions as a method for receivers to discover

I believe that the rate will not the only criteria to switch to the SPT
and it depends of multicast applications ...
Switching immediately to the SPT as you said eliminates the only
advantage of PIM-SM comparing to CBT ...

Fethi.