From: Janet Davis (jlnd_at_cs.washington.edu)
Date: Mon Jan 12 2004 - 10:54:44 PST
An addendum:
The range of valid sequence numbers is 1..MAX_TTL. When you originate a
packet, its TTL should be MAX_TTL when you call sendPkt. For forwarding,
also note that you can't send a packet with TTL 0.
On the receiving side, you should accept (i.e., process) any packet that
has a valid TTL when it arrives.
Cheers,
Janet
On Sun, 11 Jan 2004, Janet Davis wrote:
> The important thing to note is that it is not valid to send a packet with
> TTL=0. This implies that when you get a packet with TTL=1, you should
> process it if you are its destination---and then drop it if its TTL
> becomes 0. You can generalize this rule to higher TTL values.
>
> Cheers,
> Janet
>
> On Sun, 11 Jan 2004, Alissa Harrison wrote:
>
> > Janet,
> >
> > My partner and I were discussing the specification for decrementing
> > TTLs. We think that because there is ambiguity between when a TTL gets
> > decremented that interoperability problems could arise. This would
> > happen if one app decremented the TTL on the send while another
> > decremented on the recieve of a packet (when talking to another student,
> > we found we were disagreeing when to decrement). Shouldn't there be a
> > clear guideline for the whole class?
> >
> > Alissa and Jon
>
> --
> Janet Davis
> jlnd_at_cs.washington.edu
> http://www.cs.washington.edu/homes/jlnd/
>
>
-- Janet Davis jlnd_at_cs.washington.edu http://www.cs.washington.edu/homes/jlnd/ _______________________________________________ Cse461 mailing list Cse461_at_cs.washington.edu http://mailman.cs.washington.edu/mailman/listinfo/cse461
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