TELIT 910C1-LA Connecting/Disconnecting Quickly (Several units, same behaviour, not HW related)

I have a product using the TELIT 910C1-LA attached to a Rpi3 and all of them are presenting the same behaviour: the modem status is connecting/disconnecting very quickly and I can’t obtain internet connection.

The modem are using a VIVO Sim Card (Standard 4G, Not M2M) from Brazillian phone company, apn is set to zap.vivo.com.br.

Removing the SIM Card from the TELIT and placing in my iPhone, I can have internet connection normally. I am kind of newbie in Linux, my knowledges are more like “I search how to do it and I do it”, but I am having a bad time with this problem.

Thanks in advance!

dmesg | grep tty
[    0.000000] Kernel command line: coherent_pool=1M 8250.nr_uarts=1 bcm2708_fb.fbwidth=656 bcm2708_fb.fbheight=416 bcm2708_fb.fbswap=1 vc_mem.mem_base=0x3ec00000 vc_mem.mem_size=0x40000000  dwc_otg.lpm_enable=0 console=tty1 root=PARTUUID=424042b4-02 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait fastboot noswap ro
[    0.000914] console [tty1] enabled
[    0.899860] 3f201000.serial: ttyAMA0 at MMIO 0x3f201000 (irq = 81, base_baud = 0) is a PL011 rev2
[    4.219215] usb 1-1.2: GSM modem (1-port) converter now attached to ttyUSB0
[    4.220136] usb 1-1.2: GSM modem (1-port) converter now attached to ttyUSB1
[    4.221319] usb 1-1.2: GSM modem (1-port) converter now attached to ttyUSB2
[    4.222232] usb 1-1.2: GSM modem (1-port) converter now attached to ttyUSB3
[    4.222901] usb 1-1.2: GSM modem (1-port) converter now attached to ttyUSB4
[    4.231706] cdc_acm 1-1.3:1.0: ttyACM0: USB ACM device


root@pppi(ro):~# lsusb
Bus 001 Device 005: ID 04b4:0003 Cypress Semiconductor Corp.
Bus 001 Device 004: ID 1bc7:1201 Telit Wireless Solutions
Bus 001 Device 006: ID 0424:7800 Standard Microsystems Corp.
Bus 001 Device 003: ID 0424:2514 Standard Microsystems Corp. USB 2.0 Hub
Bus 001 Device 002: ID 0424:2514 Standard Microsystems Corp. USB 2.0 Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

root@pppi(ro):~# mmcli -L
    /org/freedesktop/ModemManager1/Modem/0 [Telit] LE910C1-LA


  --------------------------------
  General  |            dbus path: /org/freedesktop/ModemManager1/Modem/0
           |            device id: 0adb7baedc4a377639856e547f3ec0992e82cf12
  --------------------------------
  Hardware |         manufacturer: Telit
           |                model: LE910C1-LA
           |    firmware revision: M0F.270010
           |            supported: gsm-umts, lte
           |              current: gsm-umts, lte
           |         equipment id: 354338102582901
  --------------------------------
  System   |               device: /sys/devices/platform/soc/3f980000.usb/usb1/1-1/1-1.2
           |              drivers: option1, qmi_wwan
           |               plugin: Telit
           |         primary port: ttyUSB2
           |                ports: ttyUSB2 (at), ttyUSB3 (at), wwan0 (unknown)
  --------------------------------
  Status   |       unlock retries: sim-pin (3), sim-puk (10)
           |                state: connected
           |          power state: on
           |          access tech: lte
           |       signal quality: 71% (recent)
  --------------------------------
  Modes    |            supported: allowed: 2g; preferred: none
           |                       allowed: 3g; preferred: none
           |                       allowed: 2g, 3g; preferred: none
           |                       allowed: 4g; preferred: none
           |                       allowed: 2g, 4g; preferred: none
           |                       allowed: 3g, 4g; preferred: none
           |                       allowed: 2g, 3g, 4g; preferred: none
           |              current: allowed: 2g, 3g, 4g; preferred: none
  --------------------------------
  IP       |            supported: ipv4, ipv6, ipv4v6
  --------------------------------
  3GPP     |                 imei: 354338102582901
           |          operator id: 72406
           |        operator name: VIVO
           |         registration: home
  --------------------------------
  3GPP EPS | ue mode of operation: csps-1
  --------------------------------
  SIM      |            dbus path: /org/freedesktop/ModemManager1/SIM/0
  --------------------------------
  Bearer   |            dbus path: /org/freedesktop/ModemManager1/Bearer/0
mmcli -m 6

  --------------------------------
  General  |            dbus path: /org/freedesktop/ModemManager1/Modem/0
           |            device id: 0adb7baedc4a377639856e547f3ec0992e82cf12
  --------------------------------
  Hardware |         manufacturer: Telit
           |                model: LE910C1-LA
           |    firmware revision: M0F.270010
           |            supported: gsm-umts, lte
           |              current: gsm-umts, lte
           |         equipment id: 354338102582901
  --------------------------------
  System   |               device: /sys/devices/platform/soc/3f980000.usb/usb1/1-1/1-1.2
           |              drivers: option1, qmi_wwan
           |               plugin: Telit
           |         primary port: ttyUSB2
           |                ports: ttyUSB2 (at), ttyUSB3 (at), wwan0 (unknown)
  --------------------------------
  Status   |       unlock retries: sim-pin (3), sim-puk (10)
           |                state: connected
           |          power state: on
           |          access tech: lte
           |       signal quality: 71% (recent)
  --------------------------------
  Modes    |            supported: allowed: 2g; preferred: none
           |                       allowed: 3g; preferred: none
           |                       allowed: 2g, 3g; preferred: none
           |                       allowed: 4g; preferred: none
           |                       allowed: 2g, 4g; preferred: none
           |                       allowed: 3g, 4g; preferred: none
           |                       allowed: 2g, 3g, 4g; preferred: none
           |              current: allowed: 2g, 3g, 4g; preferred: none
  --------------------------------
  IP       |            supported: ipv4, ipv6, ipv4v6
  --------------------------------
  3GPP     |                 imei: 354338102582901
           |          operator id: 72406
           |        operator name: VIVO
           |         registration: home
  --------------------------------
  3GPP EPS | ue mode of operation: csps-1
  --------------------------------
  SIM      |            dbus path: /org/freedesktop/ModemManager1/SIM/0
  --------------------------------
  Bearer   |            dbus path: /org/freedesktop/ModemManager1/Bearer/0



GENERAL.DEVICE:                         ttyUSB2
GENERAL.TYPE:                           gsm
GENERAL.HWADDR:                         (unknown)
GENERAL.MTU:                            0
GENERAL.STATE:                          70 (connecting (getting IP configuration))
GENERAL.CONNECTION:                     giot
GENERAL.CON-PATH:                       /org/freedesktop/NetworkManager/ActiveConnection/27

GENERAL.DEVICE:                         eth0
GENERAL.TYPE:                           ethernet
GENERAL.HWADDR:                         B8:27:EB:A6:F3:50
GENERAL.MTU:                            1500
GENERAL.STATE:                          10 (unmanaged)
GENERAL.CONNECTION:                     --
GENERAL.CON-PATH:                       --
WIRED-PROPERTIES.CARRIER:               on
IP4.ADDRESS[1]:                         192.168.128.200/24
IP4.GATEWAY:                            --
IP4.ROUTE[1]:                           dst = 192.168.128.0/24, nh = 0.0.0.0, mt = 0
IP6.GATEWAY:                            --

GENERAL.DEVICE:                         lo
GENERAL.TYPE:                           loopback
GENERAL.HWADDR:                         00:00:00:00:00:00
GENERAL.MTU:                            65536
GENERAL.STATE:                          10 (unmanaged)


root@pppi(ro):~# ip addr list
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether b8:27:eb:a6:f3:50 brd ff:ff:ff:ff:ff:ff
    inet 192.168.128.200/24 brd 192.168.128.255 scope global eth0
       valid_lft forever preferred_lft forever
3: wwan0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 0e:da:5d:45:93:31 brd ff:ff:ff:ff:ff:ff
4: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether b8:27:eb:f3:a6:05 brd ff:ff:ff:ff:ff:ff
    inet 192.168.50.1/24 brd 192.168.50.255 scope global wlan0
       valid_lft forever preferred_lft forever
37: ppp0: <POINTOPOINT,MULTICAST,NOARP> mtu 1500 qdisc noop state DOWN group default qlen 3
    link/ppp
root@pppi(ro):~# ping 8.8.8.8
connect: Network is unreachable
root@pppi(ro):~#