On Friday, March 16, 2012 18:03:28 Antonio Quartulli wrote: > In case of a client X roaming from a generic node A to another node B, it > is possible that a third node C gets A's OGM but not B's. At this point in > time, if C wants to send data to X it will send a unicast packet destined > to A. The packet header will contain A's last ttvn (C got A's OGM and so > it knows it). > > The packet will travel towards A without being intercepted because the ttvn > contained in its header is the newest for A. > > Once A will receive the packet, A's state will not report to be in a > "roaming phase" (because, after a roaming, once A sends out its OGM, all > the changes are committed and the node is considered not to be in the > roaming state anymore) and it will match the ttvn carried by the packet. > Therefore there is no reason for A to try to alter the packet's route, > thus dropping the packet because the destination client is not there > anymore. > > However, C is well aware that it's routing information towards the client X > is outdated as it received an OGM from A saying that the client roamed > away. Thanks to this detail, this patch introduces a small change in > behaviour: as long as C is in the state of not knowing the new location of > client X it will forward the traffic to its last known location using > ttvn-1 of the destination. By using an older ttvn node A will be forced to > re-route the packet. Intermediate nodes are also allowed to update the > packet's destination as long as they have the information about the > client's new location.
Applied in revision b46c60b. Thanks, Marek
