Cellular Connection

To establish a cellular data link, you must configure and initiate a PPP connection. Sample options files and chat scripts are provided in the ppp peers directory /etc/ppp/peers. Anything specific to the network or connection should be placed in one of these files. Global options should be placed in /etc/ppp/options.

See the man pages on your development system for additional chat and pppd information.

Set Up Cellular Data Connection

For MTCDT-H5, MTCDT-LAT1, and MTCDT-LEU1

# Set "APN" to the APN for your cellular provider 
$ mlinux-set-apn APN

# Dial the connection (using /etc/ppp/peers/gsm config)
$ pppd call gsm

For MTCDT-LVW2

# Dial the connection (using /etc/ppp/peers/lvw2 config)
$ pppd call lvw2

Verify ppp0 is up

The route Linux utility can be used to verify the ppp0 interface is now the default route:

$ route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         33.140.12.18    0.0.0.0         UG    0      0        0 ppp0
33.140.12.18    *               255.255.255.255 UH    0      0        0 ppp0
192.168.2.0     *               255.255.255.0   U     0      0        0 eth0

The ifconfig Linux utility can be used to inspect the ppp0 interface details.

$ ifconfig ppp0
ppp0      Link encap:Point-to-Point Protocol  
          inet addr:33.140.12.18  P-t-P:33.140.12.18  Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1500  Metric:1
          RX packets:7 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:3 
          RX bytes:106 (106.0 B)  TX bytes:145 (145.0 B)

Additionally, you can view the pppd logs in /var/log/messages to see the modem dialing and assigned IP address or errors if the connection was unsuccessful.

Stop a PPP Connection

# send SIGTERM to pppd, which causes it to hang up and exit cleanly     
$ killall pppd

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