GPRS unreliable: long lasting connection fail

Niccolo Rigacci niccolo at
Mon Jan 12 11:25:27 CET 2009

On Mon, Jan 12, 2009 at 09:41:57AM +0000, Tom Yates wrote:
>> I hope to last 12 hours or so, because I do GPS live tracking
>> with position upload to the internet every 5/10 seconds.
> my battery won't last that long!

I use a car lighter adapter :-)

> i'm not sure that pppd is handling the autorecovery, though; i have a  
> vague feeling it's the call handling between the calypso chip and the 
> base station(s)

I can pass from cell to cell through long highway tunnels and the 
GSM modem handles the connection recover transparently, pppd does 
not notice it. But if the pppd notice the failure (due LCP echo 
request timeout), it cannot recover.

I had experience of PPP over DSL lines, where "persist" and 
"holdoff" parameters did the trick, but it seems that pppd on the 
FreeRunner has a bug.

Niccolo Rigacci
Firenze - Italy

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