Re: [lwip-users] Help with PPP connection - modem disconnects for no obvious reason...

[Sylvain Rochet]

Hello Freddie,

On Wed, Mar 20, 2019 at 05:56:10PM +0100, Freddie Chopin wrote:
> Hello Sylvain!
> 
> On Wed, 2019-03-20 at 17:18 +0100, Sylvain Rochet wrote:
> > Could you try with VJ_SUPPORT disabled ?
> 
> I've also thought about that and already tried that, but the result is
> almost identical:

The DiscReq LCP packet does not seem to be related at all to the PPP 
exchange, but rather just timed after the PPP session is started no 
matter what, right ? Could you try aggressively slowing down the serial 
tx routine to check that ?

Could you try using `AT+CGDATA="PPP",1` instead of `ATD*99#` ?

Your setup allows you to check using pppd instead of lwIP, maybe that's 
worth trying it to get another set of traces.

This is what I used a couple of years ago:

-- /etc/ppp/peers/gprs
show-password 
noauth
connect '/etc/ppp/peers/gprs-chat.sh'
debug debug debug
/dev/ttyUSB0
115200
defaultroute
noipdefault 
crtscts
novj
novjccomp
noaccomp
nobsdcomp
nopcomp
noccp
-ipv6

-- /etc/ppp/peers/gprs-chat.sh 
#!/bin/sh

# call the preparation chat script
/usr/sbin/chat -v -f /etc/chatscripts/gprs-prep
# wait to switch between GPRS/UMTS
sleep 20
# the final chat script:
/usr/sbin/chat -v -f /etc/chatscripts/gprs

-- /etc/chatscripts/gprs-prep 
ECHO ON
ABORT BUSY
ABORT 'NO CARRIER'
ABORT ERROR
REPORT CONNECT
TIMEOUT 20
'' ATZ
OK AT&F1
OK AT&D2
OK AT&K3
OK AT+CMEE=2
OK AT#CMEEMODE=1
OK AT#SLED=2
OK AT#GPIO=5,0,2
OK AT#TXMONMODE=1
OK AT+CPIN=1234
OK AT+CGDCONT=1,"IP","websfr","0.0.0.0",0,0
OK

-- /etc/chatscripts/gprs
ECHO ON
ABORT BUSY
ABORT 'NO CARRIER'
ABORT ERROR
REPORT CONNECT
TIMEOUT 20
'' AT+CGACT=1,1
OK AT+CGDATA="PPP",1
CONNECT \d\c

-- /etc/ppp/pap-secrets
"" gprs ""


Sylvain

signature.asc
Description: Digital signature