AirPlus MCD-800 1edf:6003

r_aleev · Post by **r_aleev** » 12 May 2010, 15:47

I switch device without any string messages and get only ttyUSB0. So I sniffed it:

http://pastebin.com/fPEYzMRe

But I didn't find MessageContent string. Everything with other length or it's not like that was described in another thread.

Could someone help me?[/code]

Post by **Josh** » 12 May 2010, 17:19

The log is from a device that is ready to use, most likely in CDC_ACM mode.
So it is either switched already (note that you have to sniff the correct device, always "mass storage") or you don't need switching at all. Chances are that the switched (or ready-to-use) device will bind to the "cdc_acm" driver in Linux and provide a "ttyACM" port instead of "ttyUSB".

Again, install the sniffing filter on the right part of the device. If it really does mode switching, then there should be components of it that are only visible if you check the box "List Devices Not Present".

You can see that you caught the right device part if your log has a "SURPRISE_REMOVAL" in one of the last lines.

r_aleev · Post by **r_aleev** » 12 May 2010, 18:28

Josh, I run VM with Windows under Linux. Do you think it can prevent to get right info from sniffer?
When I attach modem in VM Windows, I receive a messages in dmesg that new devices were attached to ttyUSB0,ttyUSB1, ttyUSB2. But wvdial doesn't see it and network manager can only add new device, but can't call.
So I will try again to sniff again under Windows machine

Post by **Josh** » 12 May 2010, 19:07

Your sniffing log looks fine, it's just from the wrong device.

It is important to understand that these modems are really many devices in one. That's why they are called "composite devices". And that is after switching.

In the Windows sniffer this is visible after the driver switched; usually there are three or more entries for the same USB ID.

With the initial mode, there is at least one more device to be regarded. But this initial devices (in all known cases a storage device) is not active (or "present") anymore after switching. It is as if it had been unplugged.

Exactly this initial storage device (which probably has a similar but different USB ID than the modem device) has to be sniffed. This is what the driver sees when plugging in, and to this device goes the switching command that we want to catch.

If the driver has installed properly on your Windows VM, sniffing might work there as well. As I said, the log you posted looked just normal.

But it is important to do the "Install Filter" operation on the right entry in the sniffer's device list. Again, check "List Devices Not Present" and you will see all USB devices ever connected to this Windows installation. Among these there is the USB ID that you look for (to find that one plug the device in Linux and run "lsusb").

r_aleev · Post by **r_aleev** » 12 May 2010, 19:56

Fine. I tried again. Could you tell me if I did it right.

Uploaded with ImageShack.us[/img]

Other devices were another usb modem and webcam

Post by **Josh** » 12 May 2010, 23:31

As I said, please check the box "List Devices Not Present".

Uninstall the filter on all other devices. You need that single storage device.

r_aleev · Post by **r_aleev** » 16 May 2010, 22:06

Josh wrote:As I said, please check the box "List Devices Not Present".

Uninstall the filter on all other devices. You need that single storage device.

Composite Device is a storage device. It changes identification from storage to composite after driver has been installed.

I sniffed strings before SURPRISE_REMOVAL, but something goes wrong. I tried both these strings, but results were the same.

1) I change mode from storage. I rid off from zero-cd /dev/sr0
2) I load usbserial module, and get USB0 and usbserial_generic driver for my device

And it doesn't depends if I do it with message string or without it.

Post by **Josh** » 17 May 2010, 00:03

r_aleev wrote:Composite Device is a storage device. It changes identification from storage to composite after driver has been installed.

Changing identification means removal of one device and discovering of annother device. As I said, the first device (storage) is in the list as a separate device.

r_aleev wrote:I sniffed strings before SURPRISE_REMOVAL, but something goes wrong. I tried both these strings, but results were the same.

Can you post the sniffing log like the first one?

r_aleev wrote:1) I change mode from storage. I rid off from zero-cd /dev/sr0
2) I load usbserial module, and get USB0 and usbserial_generic driver for my device

And it doesn't depends if I do it with message string or without it.

I'm not sure I understand that last part. What exactly are you doing to change the mode?

Also, I would like to see a "lsusb" output after plugging in Linux, before you do anything with the device.

r_aleev · Post by **r_aleev** » 17 May 2010, 13:46

1) Sniffed before driver had been installed. As you said it's a mass storage

Sniff file is 98mb large

2)Driver installed

http://pastebin.com/DYPhfBEt

3) lsusb output. Bus 003 Device 002: ID 1edf:6003

Post by **Josh** » 17 May 2010, 22:39

Hmm, this looks as if the device is really changing names.

But the log you just posted does not contain anything about a storage device. You might have missed the right moment.

To lay down the steps of sniffing more clearly:
- driver is installed, modem is unplugged
- then filter for sniffing is installed at the device you pointed out
- log is cleared to start from zero
- then modem is plugged in

There just has to be a storage device at the very beginning of the log. Something with "Class" or "SubClass" 8. This is always the initial state when the electric power is up.
The log you posted is about a device with SubClasses 2 and 10 which points to a CDC_ACM device - ready to use as a modem ...

And there is still a possibility that the device either switches itself after some time, or the detaching of the driver will make it switch (like the old Huawei modems).

If you call usb_modeswitch only with the USB IDs as parameters, there will be a SCSI inquiry of the device which removes the storage driver. Maybe that helped enough.

kent_chang · Post by **kent_chang** » 29 Jul 2010, 14:51

I ask a simple question.

Does usb_modswitch support this device aireplus MCD-800 now? Thanks.

Post by **Josh** » 29 Jul 2010, 23:33

I have had no more report about that sniffing. So in this thread is all we know about the device.
Until someone manages to sniff at the right interface.

Xelas · Post by **Xelas** » 31 Jul 2010, 23:06

Hello everybody, I bought this mcd-800 and cant make it work with my router.
hope you can explain me how to log the correct thing, cuz I have no idea how to do it. ))
Can I do it from console with usb_modeswitch and any keys? or I should have something else?

Post by **Josh** » 01 Aug 2010, 00:37

The only way promising success is to sniff at what the Windows driver is doing. See "How to Contribute" paragraph on the doc page for hints and links regarding sniffing.

Xelas · Post by **Xelas** » 01 Aug 2010, 01:03

is that what you need?
http://pastebin.com/pBkYycSR