Hi, Regarding infinite loops - you can add Time To Live (TTL), and kill the packet when it reaches 0. About multihop - I still don't see how you get duplicate packets - only if you broadcast the packet. In any other case - every node forwards the packet (a token like) and sends it only to a single next hop.
Arik On Tue, Jan 19, 2010 at 10:08, jcarneiro <[email protected]> wrote: > Hello, > In a multihop scenario the same packet may reach the destination following > different routes originating duplicate packets. > In this case in particular I am trying to figure out how to deal with > duplicates in routing nodes (not in end nodes of communication) and how to > avoid infinite cycles where a message keeps on being forwarded. > Chrs, > > João > > > > -----Original Message----- > From: Arik Sapojnik [mailto:[email protected] <[email protected]>] > Sent: Mon 1/18/2010 4:54 PM > To: jcarneiro > Cc: [email protected] > Subject: Re: [Tinyos-help] Packet tracking and duplicates > > Hi, > > Perhaps you should consider a sliding window mechanism, TCP style. > BTW - how can you receive duplicate packets? The only reason I see - it can > happen when the sender didn't receive the ack, although the receiver did > send it. In this case, the sender will send the again the same packet. > In this scenario - you need only the previous packet number. > > Arik > > > > On Mon, Jan 18, 2010 at 11:48, jcarneiro <[email protected]> wrote: > > > Hello all, > > > > To prevent duplicate packets you would look at the origin and sequence > > number. > > This would then assume that you maintain a list of packets from every > > origin meaning probably memory problems, and possibly speed inserting > > new/checking duplicates. > > My question is what data structure are you using to store this? I would > > assume a hash but I guess that's huge for the microchip. And how many > > packets do you store per origin as they may be delivered in a different > > order? > > Thanks in advance! > > > > Joao > > > > _______________________________________________ > > Tinyos-help mailing list > > [email protected] > > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > > > > > > -- > Best Regards, > Arik Sapojnik > [email protected] > > -- Best Regards, Arik Sapojnik [email protected]
_______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
