Am Montag 09 November 2009 20:47:39 schrieb Teco Boot: > Hi Thomas, > I recommend using hello messages sequence numbers only. I thought we were talking about packet sequence numbers. Message sequence numbers are something totally different. > It need more thoughts, but what about using hello msg-seq-num? > Hello messages could have msg-seq-num per interface. Then, we > have the timer based detection and the sequence number detection, > both using hello messages. > We need a RFC5444 errata on msg-seq-num if we use this. > I think it makes sense to have hello incrementing msg-seq-num per > interface and incrementing TC msg-seq-num per message. The errata > would say incrementing sequence numbers for 1-hop advertized messages > and packets must have per interface numberspaces. I don't think that makes sense Teco. > For TCs, I prefer not incrementing the msg-seq-num for repeating, > identical messages. Then, suppression or reliable transfer with > regenerating the repeating messages becomes doable. > Also, the receiving node has better knowledge on having a topology > update or not, by checking the sequence number only. Little gain here, > but still. That's why TCs have an answer-set number. > With this approach, the OLSR spec would say the repeating TC message is > not regenerated each time send out. The mechanism shall be implemented > on a generating node A for support for a suppressing node B. So it needs > implementation on all nodes for interoperability. I think you are really mixing up multiple sequence numbers in OLSR. At the moment we have three different numbers: 1.) packet sequence numbers. They have some kind of "link local scope" and can be used for estimating the packet loss on a link. 2.) message sequence numbers. These are "end to end", generated by the originator of the message and are used for duplicate detection. 3.) answer set numbers. They are only in the TCs and are increased every times the topology information a nodes sends has changed. Henning Rogge
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