Hi all,
My comments were only really based on the analysis from MANET members... I
noticed that with their 8-bit examples, if the difference between two
seqnums was 128, it would discard the incoming message, even if it was
newer. With a 16-bit sequence number, the same happens if the difference is
half of the maximum possible seqnum, so 32767...But I wondered if this was
to actually happen in practice, would it matter that the incoming message
would be discarded - If that ever happened, it would be an indicator that
something bigger was wrong. I think it wouldnt matter if we discarded the
info in that case.... I think my query has been answered!
To summarise, the text says this (unchanged since I pasted it last time):
Comparing the sequence number will identify which information is stale. The
currently stored sequence number is subtracted from the incoming sequence
number. The result of the subtraction is to be interpreted as a signed
16-bit integer, and if less than zero, then the information in the AODVv2
message is stale and MUST be discarded.
Should we still add some reference to the Newer function Charlie wrote? And
should we add any explanation that if the incoming sequence number is
greater than the current seqnum by more than half the maximum value, then
the incoming will be seen as stale? But that we dont care, because if that
happened, something bigger is wrong...?
Regards,
Vicky.
On Tue, Oct 6, 2015 at 10:07 PM, Charlie Perkins <
charles.perkins@xxxxxxxxxxxxx> wrote:
Hello Stan,
Follow-up below...
On 10/6/2015 1:56 PM, Ratliff, Stanley wrote:
1. How would sequence numbers get that far out of sync to begin
with?
They do not get that far out of sync.
2. To echo Vicky’s question, how does AODVv2 deal with that?
Given the above, AODVv2 does not have to deal with it.
3. Is there a way to get sequence numbers back into some semblance
of synchronization?
No. If the sequence number space is too small, there would be havoc.
But, the sequence number space is *not* too small, so order prevails.
Regards,
Charlie P.
