# Setting up a mobile broadband connection

## mounty1

Hello, I'm trying to use my ZTE T165i mobile 'phone as a mobile broadband modem under Gentoo.  It works fine on the same machine booted into Xubuntu (via the networkmanager applet) but I can't get off the ground with Gentoo.

Two problems to start:whereas Xubuntu creates /dev/ttyUSB0 (char. dev 188, 0) when the 'phone is plugged-in, Gentoo creates /dev/usbdev3.n_epxx where n is incremented each time the 'phone is plugged in and xx is {0[0246],8[1246]};  that is, eight device nodes are created with varying minor numbers.  The major is 255.  Since the device name is unpredictable, I can't configure the higher-level tool (kppp).  I've looked at module usbserial but it doesn't seem to help.  Some documentation says to give it vendor=0xnnnn product=0xnnnn arguments, but these result in an error on loadingEven if I create /dev/ttyUSB0 manually, with varying device numbers such as (188, 0) and (255, 0), kppp is never able to open the device.  I chmoded it to 777 every time.Any resolution that can be offered to either of these problems will be gratefully received.

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## Jaglover

You need usbserial enabled in the kernel to have /dev/ttyUSB0, udev creates it for you. Creating it manually without support in kernel will not work for obvious reasons.   :Wink: 

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## Voltago

For my Nokia E51, udev creates the node /dev/ttyACM0, you should check if this exists.

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## mounty1

 *Jaglover wrote:*   

> You need usbserial enabled in the kernel to have /dev/ttyUSB0, udev creates it for you. Creating it manually without support in kernel will not work for obvious reasons.  

 I have tried modprobe usbserial and plugging in the 'phone afterwards but it still creates /dev/usbdev3.n_epxx.

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## Jaglover

Xubuntu can do it alright? So can you with Gentoo, I'd think.  :Smile: 

What does Xubuntu load to achieve this? (lsmod)

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## mounty1

 *Jaglover wrote:*   

> Xubuntu can do it alright? So can you with Gentoo, I'd think. 
> 
> What does Xubuntu load to achieve this? (lsmod)

 <<sigh>>

Don't you think I haven't looked and tried ?  it's not usbserial, by the way.

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## Jaglover

Well, my 3G internet device is not that tricky. I had to reconfigure my kernel and add usbserial and sierra to make it work, and it creates /dev/ttyUSB0. So you are saying Xubuntu does not load usbserial?

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## mounty1

 *Jaglover wrote:*   

> So you are saying Xubuntu does not load usbserial?

 It uses the option (strange choice of name) driver.  I've now managed to modprobe option and modprobe ppp_async under Gentoo, and open the device from kppp, so the next stage is reverse-engineering the AT commands to drive the modem.  I'm looking for the log (if any) produced by networkmanager under Xubuntu.

My 'phone is not one of those listed as supported by the option driver but it does nevertheless work under Xubuntu.

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