Reply to 3g over PPP fails on v0.3.3 b250 on Thu, 12 Aug 2021 23:01:18 GMT

TypeSeven — Thu, 12 Aug 2021 23:01:18 GMT

Previously, I configured the Onion OS to use 3g over PPP according to OpenWRT WAN interface protocol on v0.3.2 b232 and was successfully able to access the internet and even share this access. However, following the same process after upgrading to v0.3.3 b250, there is no internet access even though DNS resolution is successful using a PING test. Using ifconfig, I see several bytes are transmitted but 0 bytes are received. I also see a 100% packet loss with PING. I have left this running previously to allow for 3000 packets to be sent yet had no positive results: 100% loss still. Here is a photo of the ping result.

The ONLY difference between the configuration before and after the upgrade is that the former connects to the modem via serial (/dev/ttyS0) and the latter via USB (/dev/ttyUSB2). Files in /etc/config/network and /etc/ppp/options were adjusted accordingly to reflect the changed serial ports.

Content of /etc/ppp/options

debug
/dev/ttyS0
115200
noipdefault
noaccomp
nopcomp
nocrtscts
defaultroute
noipv6
receive-all
noccp
noendpoint
usepeerdns
lock
ktune
noauth
passive
persist
connect '/usr/sbin/chat -v -t 10 -f /etc/chatscripts/3g.chat'
disconnect '/usr/sbin/chat -v -t 10 -f /etc/chatscripts/3g-disconnect.chat'
maxfail 0
lcp-echo-failure 10
lcp-echo-interval 15

Content of /etc/config/network

config interface 'cellulara'       
        option defaultroute '1'                
        option device '/dev/ttyS0'  # /dev/ttyUSB2
        option apn 'tsiot'         
        option service 'umts'         
        option proto '3g'         
        option peerdns '1'         
        option auto '0'               
        option ipv6 '0'

Although logs seen using logread show that the modem began a data session succesfully, on probing the command line arguments of pppd, I discovered that they were slightly different between v0.3.2-b232 (that works) and v0.3.3-b250 (that doesn't work).

Pppd command line from v0.3.2-b232

/usr/sbin/pppd nodetach ipparam cellulara ifname 3g-cellulara lcp-echo-interval 1 lcp-echo-failure 5 lcp-echo-adaptive set PEERDNS=1 nodefaultroute usepeerdns maxfail 1 connect USE_APN=tsiot DIALNUMBER=*99***1# /usr/sbin/chat -t5 -v -E -f /etc/chatscripts/3g.chat ip-up-script /lib/netifd/ppp-up ipv6-up-script /lib/netifd/ppp6-up ip-down-script /lib/netifd/ppp-down ipv6-down-script /lib/netifd/ppp-down noaccomp nopcomp novj nobsdcomp noauth set EXTENDPREFIX=1 lock crtscts 115200 /dev/ttyS0

Pppd command line from v0.3.3-b250

/usr/sbin/pppd nodetach ipparam cellulara ifname 3g-cellulara set PEERDNS=1 nodefaultroute usepeerdns maxfail 1 connect USE_APN=tsiot DIALNUMBER=*99***1# /usr/sbin/chat -t5 -v -E -f /etc/chatscripts/3g.chat ip-up-script /lib/netifd/ppp-up ipv6-up-script /lib/netifd/ppp6-up ip-down-script /lib/netifd/ppp-down ipv6-down-script /lib/netifd/ppp-down noaccomp nopcomp novj nobsdcomp noauth set EXTENDPREFIX=1 lock crtscts 115200 /dev/ttyUSB2

Actually, the difference is just that lcp-echo-interval 1 lcp-echo-failure 5 lcp-echo-adaptive is present in the first but absent in the second.

What I wish to now understand is why I do not have internet access. What do I need to do to ensure internet access via pppd on the v0.3.3 b250?