Sergey Ryazanov <[email protected]> writes: > On Sun, Dec 5, 2021 at 3:32 PM Bjørn Mork <[email protected]> wrote: >> Sergey Ryazanov <[email protected]> writes: >>> I am, as an occasional user of an LTE modem, never faced a case when >>> the modem is unable to register with a network due to an unconfigured >>> APN. The most prominent fact is that no one else ever faced such case >>> for a 7 years of the uqmi existence. It looks like you either ran into >>> a very special operator, or you have a buggy modem that is recovered >>> via the airplane mode. It is also possible that I do not fully >>> understand your case. >> >> I agree that this is rare. But I'm pretty sure it can happen. >> >> A more common case is that the modem picks some arbitrary previously >> used APN, e.g. profile #1. This will often be fine. But it can be really >> annoying when it isn't. For example becasue that profile was configured >> as IPv4 only and you want a dual-stack connection. > > Should not a modem reestablish a bearer as soon as a user provides a > new APN along with the connect QMI command?
I don't know what a modem should do. I only know what I've observed: If a modem is attached to a network using an IPv4 only default bearer, then you cannot connect a dual stack bearer. You can connect it, but you'll only get the IPv4 part of the session up. And connecting an IPv6 only APN is impossible in this case. >> So flight mode will sometimes be necessary when changing APN. > > Just to make it clear. Should switching to the airplane mode be a part > of connection establishing procedure (i.e. qmi.sh script)? Or would it > be enough to have the mode switching command in the uqmi utility? So a > user will be able to manually toggle the airplane mode during the APN > reconfiguration. I'm not able to agree with myself here :-) On one hand, I believe toggling airplane mode after we know the initial APN would make this more robust. On the other hand, I fear that kind of automatic stuff. Better leave if for the user as a manual toggle, I guess. >> Just don't ever force it. We don't want to lose the ability to connect >> to more than one APN (although this probably isn't supported in uqmi yet >> since you can't setup QMAP). > > Do not understand this phrase. How can the airplane mode break a > multi-bearer setup? I don't know if this was the plan or not. But I feared that someone got the idea that you could force airplane mode whenever a new APN is configured. This would obviously break existing connections. > BTW, when you are talking about QMAP, did you mean utilizing the QMAP > demux module from the kernel as it is or implementing the WWAN > subsystem ops for the qmi_wwan module. In other words, did you mean > protocol or implementation? I was talking about the (lack of) muxing setup support in uqmi. There is no way to tell the modem firmware how the different channels are supposed to be connected. Bjørn _______________________________________________ openwrt-devel mailing list [email protected] https://lists.openwrt.org/mailman/listinfo/openwrt-devel
