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PPPD modem init


I'm running  a system that connects to the internet via GPRS modem using pppd.
It seems that the cellular operator refuses to accept new connections after several days that the system is connected.

I found out that this situation can be fixed by re-register to the network (using AT+CFUN command).

Is there any "automatic" way to configure the pppd options to send a specific script (using chat) in order to initialize the modem after several connection fails?

Please note that I don't want to add it to the connect script since I don't want it to run on every connect attempt - only after several fails.

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Duncan Roe
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If this is a USB modem with a separate AT port(*) then you can do it with a cron job.
We do that sort of thing with 3G modems - periodically poll them for signal strength and also for received SMS (every 2 seconds actually).
For the Windows Embedded systems, I wrote a little program to do the actual sending but you could probably use chat.
Since this system works outside of ppp, you might want to have an interlock so it doesn't run when ppp is connecting, but the likelihood of a clash is quite small and the consequences may not be serious.

* Separate AT port to the port actually used for data transfer (typically these modems have 3 ttyUSBs associated with them)
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I've requested that this question be closed as follows:

Accepted answer: 0 points for Eyall's comment #a39199155

for the following reason:

No solution was given.
I had not realized this was a real serial modem until you posted a response this morning. It is a bit premature for you to claim that No solution was given when you had not responded to my previous post. Let me think about this.
This does sound like a candidate for a solution involving expect. Can you post the output from a failed session and the output from a good one please?
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From the application point-of-view - fail session means unable to establish a ppp connection.
It may happen because of several reasons so an output from fail/good session is not relevant.

My question was focused on pppd options without any additional software.
I guess that if such an option exists - I would get tons of comments about it.

I asked to close this question because it seems that the easiest way is to modify the ppp-up script after several fail retries without any additional tool.
I feel confident that you could automate the process with expect. But if you don't want to go that way, well that's your choice.
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I think that expect is an overkill for this problem and it might be a huge headache to compile it into my system. It's an old Embedded linux distribution that runs on a proprietary PowerPC hardware.
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No solution was given, using the pppd options as requested.