DHCP timed out after mbim-network successfull connection

[Joe]

Hi all,
First of all... I'm not a developer nor a programmer, just a simple user
which is looking for a way to make an internet dongle working using its
MBIM interface.

Hope this is the right place to ask.

So here the question:
I've an Olivetti Olicard 300 usb dongle which seems to be properly
recognized on my Slackware 14.0, after a

- linux kernel upgrade to 3.19.4

- libmbim upgrade to 1.12.2

Now usb-device command return following output:

------------------------------------------------------------------
T:  Bus=02 Lev=02 Prnt=04 Port=00 Cnt=01 Dev#= 10 Spd=480 MxCh= 0
D:  Ver= 2.00 Cls=ef(misc ) Sub=02 Prot=01 MxPS=64 #Cfgs=  1
P:  Vendor=2020 ProdID=4000 Rev=03.00
S:  Manufacturer=Network Connect
S:  Product=MT6225 
C:  #Ifs= 7 Cfg#= 1 Atr=a0 MxPwr=500mA
I:  If#= 0 Alt= 0 #EPs= 1 Cls=02(commc) Sub=0e Prot=00 Driver=cdc_mbim
I:  If#= 1 Alt= 1 #EPs= 2 Cls=0a(data ) Sub=00 Prot=02 Driver=cdc_mbim
I:  If#= 2 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=02 Prot=01 Driver=option
I:  If#= 3 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
I:  If#= 4 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
I:  If#= 5 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
I:  If#= 6 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50
Driver=usb-storage
-------------------

Morever /dev/cdc-wdm* device is created and it is linked to a wwan*
network interface.

So, tha idea to estabilish internet connection over wwan* is to launch
mbim-network script and then bring up wwan interface assigning to it 
IP obtained by my ISP (IPv4).

I've configured my APN in /etc/mbim-network.config and have launched:

-----------------------------------
# mbim-network /dev/cdc-wdm1 start
Loading profile...
    APN: ibox.tim.it
    Querying subscriber ready status 'mbimcli -d /dev/cdc-wdm1
    --query-subscriber-ready-status --no-close'...
    [/dev/cdc-wdm1] Subscriber ready status retrieved: Ready state:
    'initialized' Subscriber ID: 'xxxxxxxxxxxxxx' SIM ICCID:
    'xxxxxxxxxxxxxxxxxxx' Ready info: 'unknown' Telephone numbers: (1)
    'xxxxxxxxx' [/dev/cdc-wdm1] Session not closed: TRID: '3'
    Saving state... (TRID: 3)
    Querying registration state 'mbimcli -d /dev/cdc-wdm1
    --query-registration-state --no-open=3 --no-close'...
    [/dev/cdc-wdm1] Registration status: Network error: 'unknown'
    Register state: 'home' Register mode: 'automatic' Available data
    classes: 'gprs, edge, umts, hsdpa, hsupa' Current cellular class:
    'gsm' Provider ID: '22201' Provider name: '22201' Roaming text:
    'unknown' Registration flags: 'packet-service-automatic-attach'
    [/dev/cdc-wdm1] Session not closed: TRID: '4'
    Saving state... (TRID: 4)
    Attaching to packet service with 'mbimcli -d /dev/cdc-wdm1
    --attach-packet-service --no-open=4 --no-close'...
    Saving state... (TRID: 5)
    Starting network with 'mbimcli -d /dev/cdc-wdm1
    --connect=ibox.tim.it --no-open=5 --no-close'...
    Network started successfully
    Saving state... (TRID: 6)
------------------------------

At this point the green led of my dongle begins to blink like when it is
properly connected to internet.
Ok, now It should be possible to bring up "wwan1" sleeping interfce by
call the interfaces init script.
Following slackware way... I've added the following lines to

/etc/rc.d/rc.inet1.conf

-------------------------------
# Config information for wwan0:
IFNAME[5]="wwan0"
IPADDR[5]=""
NETMASK[5]=""
USE_DHCP[5]="yes"
DHCP_HOSTNAME[5]=""
DHCP_KEEPRESOLV[5]="yes"
DHCP_KEEPNTP[5]="yes"

# Config information for wwan1:
IFNAME[6]="wwan1"
IPADDR[6]=""
NETMASK[6]=""
USE_DHCP[6]="yes"
DHCP_HOSTNAME[6]=""
DHCP_KEEPRESOLV[6]="yes"
DHCP_KEEPNTP[6]="yes"
---------------------

Ok so now I've to just launch:

/etc/rc.d/rc.inet1 wwan1_start

And my wwan1 interface should wake up and obtain its ip by my ISP
through DHCP. Let's see what's happens instead...

---------------------------------
# /etc/rc.d/rc.inet1 wwan1_start
Polling for DHCP server on interface wwan1:
dhcpcd[4345]: version 5.5.6 starting
dhcpcd[4345]: wwan1: sending IPv6 Router Solicitation
dhcpcd[4345]: wwan1: broadcasting for a lease
dhcpcd[4345]: wwan1: sending IPv6 Router Solicitation
dhcpcd[4345]: wwan1: sending IPv6 Router Solicitation
dhcpcd[4345]: timed out
dhcpcd[4345]: allowing 8 seconds for IPv4LL timeout
dhcpcd[4345]: wwan1: sending IPv6 Router Solicitation
dhcpcd[4345]: wwan1: no IPv6 Routers available
dhcpcd[4345]: timed out
------------------------

So... Sadly dhcp timed out and my internet connection still cannot work.

I've read around It is possible that my dongle mbim intercface doesn't
support IP assing by DHCP...
It seems on the other hand that libmbim is able to directly obtain ISP
provided IP.

The idea seems to be: dump your IP using libmbim in some way. Then
assing it statically to wwan interface...
And lastly configure your default route.

All this last lines are just a my rough guess so I've subscribed there to
ask you some hint to make my dongle and my wwan interface properly connected
to the net.

Hope you can help, and hope my english is not too bad.
All suggestions are greatly appreciated!
Thanks in advance!  :)