My neighbour's modem again
I posted in the middle part of January about my neighbour's external modem that wouldn't dial out and failed with "NO CARRIER". This was running under Progeny Debian. The latest development is that we have discovered that it will dial when running in Single User mode on his machine but not otherwise. It will also work perfectly on my machine running either Debian 2.2 or the same version of Progeny that I've installed on his machine and with a simple ATZ initialisation string. Does this give any clues as to why it won't work on his machine? All advice gratefully received. Barry Samuels
On 26-Jan-02 bsamuels@beenthere-donethat.org.uk wrote:
The latest development is that we have discovered that it will dial when running in Single User mode on his machine but not otherwise.
It will also work perfectly on my machine running either Debian 2.2 or the same version of Progeny that I've installed on his machine and with a simple ATZ initialisation string.
Does this give any clues as to why it won't work on his machine?
Hi Barry, This suggests one of [at least] two things. a) The dialup config changes when the bootup progresses from level 1 (single user) to level 3 (multiuser), though I can't think why that should happen; b) The init stuff that cuts in when level 3 is reached does a hardware probe, and when it finds the modem does something to it which puts it on the wrong foot. One test to try would be to boot into multiuser with the modem switched off (or even uplugged), then switch it on and try dialling. I guess this would only work with an external modem, though (unless you are prepared to take the chance of "hot-plugging" an internal one). In any case, don't forget that in these situations 'minicom' is your friend: everything you type goes straight into the modem, and all modem responses are visible as they happen (unless response echo has itself been turned off). So you can see exactly what is happening. And you can try a raw dialup in minicom from multiuser mode, and compare with what happens from single-user. Minicom can also be useful for debugging your ISP, by the way! Good luck, Ted. -------------------------------------------------------------------- E-Mail: (Ted Harding) <Ted.Harding@nessie.mcc.ac.uk> Fax-to-email: +44 (0)870 167 1972 Date: 26-Jan-02 Time: 12:54:04 ------------------------------ XFMail ------------------------------
(Ted Harding) <Ted.Harding@nessie.mcc.ac.uk> wrote:
On 26-Jan-02 bsamuels@beenthere-donethat.org.uk wrote:
The latest development is that we have discovered that it will dial when running in Single User mode on his machine but not otherwise.
It will also work perfectly on my machine running either Debian 2.2 or the same version of Progeny that I've installed on his machine and with a simple ATZ initialisation string.
Does this give any clues as to why it won't work on his machine?
Hi Barry, This suggests one of [at least] two things. a) The dialup config changes when the bootup progresses from level 1 (single user) to level 3 (multiuser), though I can't think why that should happen; b) The init stuff that cuts in when level 3 is reached does a hardware probe, and when it finds the modem does something to it which puts it on the wrong foot.
Having got it to work on my machine running the same (I think!) version of Progeny I would have thought that b) would also apply then but the modem works and with a simple ATZ initialisation.
One test to try would be to boot into multiuser with the modem switched off (or even uplugged), then switch it on and try dialling. I guess this would only work with an external modem, though (unless you are prepared to take the chance of "hot-plugging" an internal one).
It is an external modem. I'll try it.
In any case, don't forget that in these situations 'minicom' is your friend: everything you type goes straight into the modem, and all modem responses are visible as they happen (unless response echo has itself been turned off). So you can see exactly what is happening.
And you can try a raw dialup in minicom from multiuser mode, and compare with what happens from single-user.
Minicom can also be useful for debugging your ISP, by the way!
In this case Minicom is an absent friend as the current installation of Progeny (from ISO images that I downloaded) on his machine lacks a number of things, including Minicom, and we are trying to get it connected to the Internet to update it.
Good luck, Ted.
Looks as though we may need it. Barry Samuels
On Sat, 26 Jan 2002 12:13:52 bsamuels@beenthere-donethat.org.uk wrote:
I posted in the middle part of January about my neighbour's external modem that wouldn't dial out and failed with "NO CARRIER". This was running under Progeny Debian.
The latest development is that we have discovered that it will dial when running in Single User mode on his machine but not otherwise.
One possibility is that in multi-user mode more than one program is trying to talk to the modem at the same time. If you have lsof installed you could use that to stop things that have the /dev/ttyS0 device (or whatever device your modem is on) open. Alternatively maybe post the list of processes running in multi-user (with ps -ef) mode and see if we can spot things that look modem related. Steve.
Steve Fosdick <fozzy@pelvoux.demon.co.uk> wrote:
On Sat, 26 Jan 2002 12:13:52 bsamuels@beenthere-donethat.org.uk wrote:
I posted in the middle part of January about my neighbour's external modem that wouldn't dial out and failed with "NO CARRIER". This was running under Progeny Debian.
The latest development is that we have discovered that it will dial when running in Single User mode on his machine but not otherwise.
One possibility is that in multi-user mode more than one program is trying to talk to the modem at the same time. If you have lsof installed you could use that to stop things that have the /dev/ttyS0 device (or whatever device your modem is on) open. Alternatively maybe post the list of processes running in multi-user (with ps -ef) mode and see if we can spot things that look modem related.
Steve.
Bear in mind that an initialisation string sent to the modem first returns 'OK'. Surely that wouldn't happen if another application was accessing the modem. I'll try the ps -ef as you suggest. Barry Samuels
participants (3)
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bsamuels＠beenthere-donethat.org.uk -
Steve Fosdick -
Ted.Harding＠nessie.mcc.ac.uk