I use pppd. One simple interactive config tool for it is pppconfig that will detect modem, ask some ISP specific details, username-password, etc. It is available from the repo if you installed Debian or Ubuntu ARM on the board.

In details it actually modifies or adds some files:

• /etc/peers/chap-secrets the “password”
• /etc/peers/some-provider username and modem port e.g. /dev/ttyUSB0
• /etc/chatscripts/some-provider some APN definition (if necessary) and other dialing options

Some examples of the manually configured files above are available in my zoom camera github. There I need to manually edit the chatscripts due to specific ISP I use here (the default should work for most ISPs as I found out to be true here).

Hope that helps.

haw i can configure the USB Serial Modem 3g usb modem in ebv beagle boars