What were the exact batman-adv versions at the time you made those graphs for the shown nodes as well as any intermediate nodes (although if I got your setup right then the nodes in those graphs do not have any intermediate batman-adv hops involved, do they?)?
Does it make a difference if you make the entries in the neighbor solicitation table permanent (e.g. with 'ip -6 neigh')? Do the same spikes appear with a 'batctl ping' (or if adding such graphs is quite a hassle then at least, is the overall 'batctl ping' packet loss similar to the one from the ip ping)? Do you see any "Changing route towards" events in the batman-adv logs between these supposedly always direct neighbors - if yes, maybe with a similar frequency? Or even better, check whether the same packet loss appears when isolating any of such pairs of nodes so that no batman-adv route changes could happen at all. Do these packet loss events correlate with periods of high OGM loss (e.g. check for high last-seen values in the originator table)? > Gesendet: Donnerstag, 03. Januar 2013 um 17:17 Uhr > Von: "Jan Lühr" <[email protected]> > An: "The list for a Better Approach To Mobile Ad-hoc Networking" > <[email protected]> > Betreff: Re: [B.A.T.M.A.N.] Packet-Loss-Peaks in a Freifunk-Network > > Hello, > > Am 03.01.2013 um 17:05 schrieb Marek Lindner: > > > On Thursday, January 03, 2013 23:52:42 Jan Lühr wrote: > >> Well, I started echoing on the underlying VPN-connection as well and > >> changed the chart-titles for clearance: > >> > >> In chart 4 and chart 5 RTT / Loss from kif.kbu to node-1 is measured. > >> In chart 4 kif is sending ICMPv6 to the link-local address of > >> bat0-interface - in chart 5 the link_local address of the underlying > >> vpn-interface is used. > > > > All tests are from the same node to the same node using exactly the same > > means > > (protocols, etc) with the exception of batman-adv ? Sorry for my dumb > > question > > but your topology might be obvious to you but isn't for me (us?). > > yes. > > > > > The spikes on your graphs show the packet loss ? > > yes. > > > How can we have a RTT < 50ms > > while experiencing packet loss ? > > > Collectd uses a ping rate of 10 seconds here, RTT >= 0.9s = 900ms is "loss" > If 1/3 arrives in < 50ms and 2/3 are lost, RTT is < 50ms while loss = 2/3. > > Btw. I you wanna see our setup, we can take a tour via ssh / tmux - I can > provide the rrd-Files, too. > You can contact my by jabber ([email protected]) as well, > > Thanks, > Keep smiling > yanosz > >
