From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <4EC2A86F.2000804@inti.gob.ar> Date: Tue, 15 Nov 2011 14:59:11 -0300 From: gtolon@inti.gob.ar MIME-Version: 1.0 References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [B.A.T.M.A.N.] Problem to find better Route 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: b.a.t.m.a.n@lists.open-mesh.org Thank you for your answers. I copy the Originator's tables for the three nodes: A) (MAC: b2:48:7a:c8:a2:65) root@OpenWrt:/# batctl o [B.A.T.M.A.N. adv 2011.2.0, MainIF/MAC: wlan1/b2:48:7a:c8:a2:65 (bat0)] Originator last-seen (#/255) Nexthop [outgoingIF]: Potential nexthops ... 16:d6:4d:3a:3c:3c 0.790s (213) 16:d6:4d:3a:3c:3c [ wlan1]: 16:d6:4d:3a:3d:d8 (193) 16:d6:4d:3a:3c:3c (213) 16:d6:4d:3a:3d:d8 0.810s (255) 16:d6:4d:3a:3d:d8 [ wlan1]: 16:d6:4d:3a:3c:3c (190) 16:d6:4d:3a:3d:d8 (255) B) (MAC: 16:d6:4d:3a:3c:3c) root@OpenWrt:/# batctl o [B.A.T.M.A.N. adv 2011.2.0, MainIF/MAC: wlan1/16:d6:4d:3a:3c:3c (bat0)] Originator last-seen (#/255) Nexthop [outgoingIF]: Potential nexthops ... b2:48:7a:c8:a2:65 0.840s (235) b2:48:7a:c8:a2:65 [ wlan1]: 16:d6:4d:3a:3d:d8 (236) b2:48:7a:c8:a2:65 (235) 16:d6:4d:3a:3d:d8 0.640s (253) 16:d6:4d:3a:3d:d8 [ wlan1]: b2:48:7a:c8:a2:65 (205) 16:d6:4d:3a:3d:d8 (253) C) (MAC: 16:d6:4d:3a:3d:d8) root@OpenWrt:/# batctl o [B.A.T.M.A.N. adv 2011.2.0, MainIF/MAC: wlan1/16:d6:4d:3a:3d:d8 (bat0)] Originator last-seen (#/255) Nexthop [outgoingIF]: Potential nexthops ... 16:d6:4d:3a:3c:3c 0.060s (208) 16:d6:4d:3a:3c:3c [ wlan1]: b2:48:7a:c8:a2:65 (182) 16:d6:4d:3a:3c:3c (208) b2:48:7a:c8:a2:65 0.090s (234) b2:48:7a:c8:a2:65 [ wlan1]: 16:d6:4d:3a:3c:3c (182) b2:48:7a:c8:a2:65 (234) This is a typical state of the tables. We tryed setting the hop pennalty parameter to 1, but the behaviour hasn't changed. > ------------------------------ > > Message: 4 > Date: Tue, 15 Nov 2011 00:43:13 +0100 > From: Antonio Quartulli > To: The list for a Better Approach To Mobile Ad-hoc Networking > > Subject: Re: [B.A.T.M.A.N.] Problem to find better Route > Message-ID:<20111114234312.GA28724@ritirata.org> > Content-Type: text/plain; charset=utf-8 > > Hello Gabriel, > > On Mon, Nov 14, 2011 at 04:53:22 -0300,gtolon@inti.gob.ar wrote: >> > Hi. We are using batman-adv 2011.2.0 with Openwrt Backfire-rc6 on D-Link >> > routers, and we're making some tests with iperf to measure bitrate >> > capabilities between nodes. When we put three nodes aligned we notice >> > that the obtained bitrate between the extreme nodes strongly depends on >> > the batman path between them. To make it clear, we have: >> > >> > A ---------- B ---------- C >> > >> > With a dinstance of about 20 meters between A and B, and the same >> > distance between B and C. The problem is that sometimes, A and C get >> > connected directly in terms of batman-adv protocol (checked with batctl >> > o), and when that happens, the bitrates are very poor (less than 1Mbps), >> > like if B wasn't there. In fact we disconnected B and obtained very >> > similar results. >> > >> > Then we reduced tx power settings on A and C, forcing the B hop between >> > them, and we got much better speeds (~20Mbps). We've read about ELP and >> > think that maybe simple OGM messages are not good to measure link >> > quility between A and C in this example, could that be the problem? In >> > that case is there a way to fix this with actual batman-adv algorithms? >> > Thanks in advance! >> > >> > Gabriel >> > > I think other people will give you better answer than this one, but just as > start: OGM are sent in broadcast, which by definition uses a low rate that > implies "better transmission than higher rates". > Therefore a link having an high TQ doesn't necessarily has a good quality at > "high rates" (as you are experiencing). > > In my opinion the problem resides in the fact that batman-adv uses broadcast > packets to measure link qualities which leads to the aforementioned problem. > > I don't know if ELP would help in this sense because as far as I know it still > uses broadcast packets. > > Please guys correct me if I am wrong. > > > Cheers, > > > > -- Antonio Quartulli ..each of us alone is worth nothing.. Ernesto > "Che" Guevara ------------------------------ Message: 5 Date: Tue, 15 > Nov 2011 09:40:36 +0800 From: Marek Lindner > To: "The list for a Better Approach To Mobile Ad-hoc Networking" > Subject: Re: [B.A.T.M.A.N.] Problem > to find better Route Message-ID: > <201111150940.36605.lindner_marek@yahoo.de> Content-Type: Text/Plain; > charset="iso-8859-1" Hi, >> > With a dinstance of about 20 meters between A and B, and the same >> > distance between B and C. The problem is that sometimes, A and C get >> > connected directly in terms of batman-adv protocol (checked with batctl >> > o), and when that happens, the bitrates are very poor (less than 1Mbps), >> > like if B wasn't there. In fact we disconnected B and obtained very >> > similar results. > would you mind sharing the orignator tables of the involved nodes ? > > >> > Then we reduced tx power settings on A and C, forcing the B hop between >> > them, and we got much better speeds (~20Mbps). We've read about ELP and >> > think that maybe simple OGM messages are not good to measure link >> > quility between A and C in this example, could that be the problem? In >> > that case is there a way to fix this with actual batman-adv algorithms? > You can play with the hop penalty parameter to encourage batman to use fewer > or more hops (depending on your needs). > > Regards, > Marek > > > ------------------------------