Hello Hendrik - You are right. Batman uses Originator messages, that contain at least a Originator address, a TTL and a Sequence Number. So to name it Originator Sequence Number tuple is somehow redundant and confusing. The term was introduced to describe what is going on in the daemon. Not in the way I guess you mean. Batman nodes never send routing information to others in the way that a message contains routing information about the topology - well, there is one special case when a node sends information about its local view to a visualisation server. But this has nothing to do with the routing algorithm as such, this is just to provide information necessary to build topology graphs. Batman nodes just rebroadcast Originator messages according to a set of rules. A node rebroadcasts a Originator message, if: a.) The Originator is a single hop neighbor. If the Originator is a bidirectional neighbor and the best ranking router to route traffic to itself the Originator message gets re-broadcasted after decreasing TTL by 1 b.) The Originator is a single hop neighbor. If the Originator is a bidirectional neighbor but not the best ranking router to route traffic to itself the Originator message is re-broadcasted with the unidirectional flag added and - you guessed it - TTL decreased by 1. c.) The Originator is a single hop neighbor. If the Originator is not a bidirectional neighbor the Originator message is re-broadcasted with the unidirectional flag added and - you know it - TTL decreased by 1. d.) The Originator is not a single hop neighbor. If we receive a re-broadcasted message from a single hop neighbor repeating a OGM from someone in the distance it gets repeated if our single hop neighbor is bidirectional and the best ranking neighbor on route to that Originator which created the message. And - of course - TTL decreased by 1. In all other cases OGMs are not repeated. A Originator will see others repeating its Originator messages if the radio conditions provide a bidirectional link. This is the only case when we send feedback to others - btw. we are not addressing them as such cause radio is a broadcast medium ;) Of course a OGM with unidirectional flag is only helpful for its Originator, to learn: Hey, this node has seen me and I have seen it. So we have a bidirectional link! The strength of B.A.T.M.A.N. is it doesn't rely on other nodes opinions/informations about topology that would have to be synchronized. A process known to fail and create confusion in a wireless network... B.A.T.M.A.N. learns from the fact that broadcasts are received or missing, not from information about routing topology contained in broadcasts. The information who is the Originator is the only information in the package about topology as such... I guess d.) is somehow what you wondered about. We won't send our knowledge back to the Originator in the distance. It will receive our OGMs containing only the information that we exist - if radio conditions / topology allow it. Right, it is the timeout of the last valid OGM-message when we delete a route. Best ranking neighbor is the neighbor that gives us the Originator message with unknown sequence number more reliable and quicker than others. HTH, cu elektra