Re: PIM : detecting duplicate packet

On Dec 9, 2006, at 9:27 PM, tajay wrote:

> Hi,
> Most of the opimization algorithms in PIM depends on detecting  
> duplicate packets.
> e.g
> (1) sending register stop once RP starts receiving duplicate packets
> (2) DR  <at>  source sends prunes (S,G) from RPTree whenever it receives  
> duplicate
> packets from source.
>
> Is there any specific way to identify duplicate packets? And how  
> feasible it
> is to detect duplicate packets at very high rate traffic?

To correct a slight misunderstanding, it isn't "duplicate" packets  
that are
being detected, but the arrival of packets on an alternate network  
path.  It is
'assumed' that this will ensure there is no loss of data when  
switching from
the RP-tree to the shortest-path, or from pim registration to the  
shortest-path.

And you have #2 wrong, it isn't the DR at the source, but it is the  
last-hop router,
which may or may not be the DR, that joins to the spt.

To be honest, it has never been clearly shown that the complications