On Thu, 2011-05-05 at 01:15 +0300, Uwe Geuder wrote: > I understand that this a upstream list and most readers are interested > in the bleeding edge. However, I have to support some systems for > "naive" users and I prefer to use a plain vanilla distribution as long > as possible. So please bear with my question regarding versions > straight from the museum... > > On Ubuntu 10.04 (long time support) they have nm version 0.8-0ubuntu3
So what you want to do here is also grab modem-manager logs as described here: http://live.gnome.org/NetworkManager/Debugging under the "Debugging NetworkManager 0.8.x 3G connections" section. > The USB modem in use is a Nokia CS-17. (I know that if you search for > trouble, you select a 3G USB modem. Unfortunately this variant is > really by orders of magnitude cheaper in this case than anything more > reliable.) Huh, because they are $120 on eBay which isn't cheap at all :) Otherwise I'd buy one. > The good news is that the CS-17 works even with that old software. > > The bad news is that it's completely unreliable. Some 30%-50% of the > connection attempts just fail. Unfortunately the failures seem to come > in waves. If it fails the first time, it will also fail the 2nd, 3rd > etc. Removing the modem does not help. But 1 or 2 hours later it might > just work again. Alternatively if I want to repeat the problem, I can > make 15 connections in a row without any failure. So in this case, more logs from NetworkManager's PPP debugging would help, as would the ModemManager logs as described above. > The other problem is that while the connection typically stays open > for hours during normal web browsing, it will disconnect with quite > high probability when downloading bigger files. Today I needed 4 attempts > to download a 20 MB file. What does the PPP debugging say when this happens? NM wont' terminate the connection unless PPP says it's down. Dan > I would exclude network-side problems or weak signal, because I use 3G > data on the same network nearly all day long on my smartphone without > such problems. Additionlly, when the USB modem fails to connect I can use > my phone as the modem using the data cable and everything works. > > So how could I debug this? Is it a Linux-side problem or a firmware problem > in the CS-17? (Haven't had a chance to test it with M$ yet) > > From searching in the mailing list archives I found 2 debugging hints: > > 1. starting nm from command line as > > # NM_SERIAL_DEBUG=1 NM_PPP_DEBUG=1 NetworkManager --no-daemon | tee log.txt > > That works nicely. When the connection attempt fails I see how PPP > negotiation starts, but it doesn't seem to get any reply. > > sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x5c8b3860> <pcomp> <accomp>] > > After 5 repetitions pppd seems to give up and nm complains that the > connection failed. > > (Not sure whether NM_SERIAL_DEBUG has any effect, I don't think I see that > variable in the source code of my version) > > The problem is that using the command line (and root) is OK for me on > my test machine, but not for the user in question on the real target > machine. So I'd like to configure the "real" service such that logging is > always on. > > I tried to do so by adding the 2 environment variables to > /etc/init/network-manager.conf (Ubuntu uses upstart) > > env NM_PPP_DEBUG=1 > env NM_SERIAL_DEBUG=1 > exec NetworkManager > > Unfortunately that seems to have no effect to the pppd logging. The > pppd stuff that I can see when running with --no-daemon does just not > appear in syslog, neither in successful nor in failing cases. (I have > checked from /proc/nnn/environ that the environment variables really > end up in the network-manager process) > > Also the debug parameter appears on the pppd command line as shown in syslog. > > How can I get pppd logging when running as a daemon? > > 2. The other hint I found in the mailing archive was a config file entry > > [logging] > level=WARN > > I changed that to level=DEBUG, but I don't think it made a > difference. Could not find such parameter in my source code. Has it > possibly been added only in a later version? > > > Yesterday I read in some forum that killing modem-manager after a > failed connection attempt helps. Today I had only very few failed > attempts in my testing and killing modem-manager helped each time. Not > yet sure whether this is really a reliable work-around. If yes, I > could of course script it. > > Does the problem description ring any bells? If you remember specific fixes > that solve these issues, I might try to backport them to my > version. Or just install a newer version manually. > > Regards, > > Uwe > > > P.S. Yes, I am aware of the modeswitching. I left that out from the > description above, I'm sure that the modem was always in the right > mode. > _______________________________________________ > networkmanager-list mailing list > networkmanager-list@gnome.org > http://mail.gnome.org/mailman/listinfo/networkmanager-list _______________________________________________ networkmanager-list mailing list networkmanager-list@gnome.org http://mail.gnome.org/mailman/listinfo/networkmanager-list