From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4804FC55.3010407@gmx.net> Date: Tue, 15 Apr 2008 21:04:53 +0200 From: elektra MIME-Version: 1.0 Subject: Re: [B.A.T.M.A.N.] Node keeps switching back and forth References: <7BE4D55B-B938-45A8-BCF4-923632152CFC@philippeapril.com> <018CC2A5-4DD5-421B-AD00-AF9B3CC50D2B@philippeapril.com> <200804160202.23971.lindner_marek@yahoo.de> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Reply-To: The list for a Better Approach To Mobile Ad-hoc Networking List-Id: The list for a Better Approach To Mobile Ad-hoc Networking List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: The list for a Better Approach To Mobile Ad-hoc Networking Hi Philippe - fast switching of a route is a problem if does cause routing loops. I have verified in a 7x7 physical mesh grid that B.A.T.M.A.N. doesn't loop - ever. And - yes - particularly in my tests where I saturated the grid with several massive traffic streams that were colliding in the center of the grid, B.A.T.M.A.N. was switching routes quite often (every few seconds). I see therefore no point in adding hysteresis. If someone can show that there is an issue we can add hysteresis to the protocol. cu elektra > I tried that but I think it's only for switching from a gateway to > another gateway. > > My problem is for switching from an intermediate node, to another... > > For example, imagine a square where there's a node in each corner at > almost equal distance/signal quality (to keep things simple) with some > interference, and only one of them is the gateway, and the node > opposite to the gateway can't reach the gateway directly. > > That node (opposite to the gateway) has the choice between two nodes > to get to the gateway. > > In my/this case, it keeps switching from one to the other (since the > quality is almost the same on each). I guess it doesn't help keeping > things reliable for laptop connections behind... Playing with -r > doesn't seem to help because I only have one gateway node. > > Am I right? > > On 15-Apr-08, at 2:02 PM, Marek Lindner wrote: > >> >>> As soon as signal from node2 to node1 goes down from let's say 250 to >>> 240, if another connection to the gateway's quality is 241, it'll >>> switch as soon as it hits 240... Then when quality comes back up to >>> 242, it switches back to node1. >>> >>> I don't think it's very good to switch as soon as the quality is >>> higher somewhere else, it should at least "give it a chance" by either >>> having a threshold, or switch only if it's been in a more degraded >>> state for more than x minutes, etc. >>> >>> Is there something I can do to influence that? Did I miss a command >>> line argument? >> >> You can use e.g. "-r 20" to switch the gateway as soon as the TQ >> difference is >> bigger than 20. >> >>> From "batmand -H": >> >> -r routing class (only needed if gateway class = 0) >> default: 0 -> set no default route >> allowed values: 1 -> use fast internet connection >> (gw_flags * TQ) >> 2 -> use stable internet connection (TQ) >> 3 -> use fast-switch internet connection >> (TQ but >> switch as soon as a better gateway appears) >> >> XX -> use late-switch internet connection >> (TQ but >> switch as soon as a gateway appears which is XX TQ better) >> >> Greetings, >> Marek >> >> _______________________________________________ >> B.A.T.M.A.N mailing list >> B.A.T.M.A.N@open-mesh.net >> https://list.open-mesh.net/mm/listinfo/b.a.t.m.a.n > > _______________________________________________ > B.A.T.M.A.N mailing list > B.A.T.M.A.N@open-mesh.net > https://list.open-mesh.net/mm/listinfo/b.a.t.m.a.n >