USB_ModeSwitch

Posted: **23 Jul 2011, 11:18**

I have a USB Modem MMX 372 G to connect internet. Installed usb-modswitch it via Synaptics.

without usb-modswitch installed lsusb showed

Code: Select all

  Bus 002 Device 002: ID 05c6:9000 Qualcomm, Inc.

and with usb-modswitch installed lsusb showed

Code: Select all

  Bus 002 Device [b]003[/b]: ID 05c6:9000 Qualcomm, Inc.

and following is /var/log/messages when I connect the USB modem and connect it for the first time the USB modem (without usb-modswitch)

Jul 24 08:37:42 abhi kernel: [ 110.200159] usb 2-2: new high speed USB device using ehci_hcd and address 2
Jul 24 08:37:43 abhi kernel: [ 110.353219] usb 2-2: configuration #1 chosen from 1 choice
Jul 24 08:37:43 abhi kernel: [ 110.428596] Initializing USB Mass Storage driver...
Jul 24 08:37:43 abhi kernel: [ 110.428971] scsi4 : SCSI emulation for USB Mass Storage devices
Jul 24 08:37:43 abhi kernel: [ 110.429219] usbcore: registered new interface driver usb-storage
Jul 24 08:37:43 abhi kernel: [ 110.429223] USB Mass Storage support registered.
Jul 24 08:37:48 abhi kernel: [ 115.432060] scsi 4:0:0:0: CD-ROM Micromax HSUPA Modem 2.31 PQ: 0 ANSI: 0
Jul 24 08:37:48 abhi kernel: [ 115.439083] sr1: scsi-1 drive
Jul 24 08:37:48 abhi kernel: [ 115.442025] sr 4:0:0:0: Attached scsi generic sg2 type 5
Jul 24 08:37:55 abhi kernel: [ 122.268742] sr: Sense Key : Hardware Error [current]
Jul 24 08:37:55 abhi kernel: [ 122.268749] sr: Add. Sense: No additional sense information

and with usb-modswitch installed

tail -f /var/log/messages

shows

Jul 23 07:56:35 abhi kernel: [18305.683958] usbcore: registered new interface driver usbserial
Jul 23 07:56:35 abhi kernel: [18305.684079] USB Serial support registered for generic
Jul 23 07:56:35 abhi kernel: [18305.684950] usbserial_generic 2-2:1.0: generic converter detected
Jul 23 07:56:35 abhi kernel: [18305.687166] usb 2-2: generic converter now attached to ttyUSB0
Jul 23 07:56:35 abhi kernel: [18305.687194] usbserial_generic 2-2:1.1: generic converter detected
Jul 23 07:56:35 abhi kernel: [18305.689045] usb 2-2: generic converter now attached to ttyUSB1
Jul 23 07:56:35 abhi kernel: [18305.689076] usbserial_generic 2-2:1.3: generic converter detected
Jul 23 07:56:35 abhi kernel: [18305.689615] usb 2-2: generic converter now attached to ttyUSB2
Jul 23 07:56:35 abhi kernel: [18305.689712] usbcore: registered new interface driver usbserial_generic
Jul 23 07:56:35 abhi kernel: [18305.689716] usbserial: USB Serial Driver core

after installing usb-modswitch I did

root@abhi:~# modprobe usbserial vendor=0x05c6 product=0x9000

Next set of commands

dmesg | grep -e "modem" -e "tty"

shows

[ 0.000000] console [tty0] enabled
[18305.687166] usb 2-2: generic converter now attached to ttyUSB0
[18305.689045] usb 2-2: generic converter now attached to ttyUSB1
[18305.689615] usb 2-2: generic converter now attached to ttyUSB2

root@abhi:~# wvdialconf

Editing `/etc/wvdial.conf'.

Scanning your serial ports for a modem.

Modem Port Scan<*1>: S0 S1 S2 S3
WvModem<*1>: Cannot get information for serial port.
ttyUSB0<*1>: ATQ0 V1 E1 -- failed with 2400 baud, next try: 9600 baud
ttyUSB0<*1>: ATQ0 V1 E1 -- failed with 9600 baud, next try: 9600 baud
ttyUSB0<*1>: ATQ0 V1 E1 -- and failed too at 115200, giving up.
WvModem<*1>: Cannot get information for serial port.
ttyUSB1<*1>: ATQ0 V1 E1 -- OK
ttyUSB1<*1>: ATQ0 V1 E1 Z -- OK
ttyUSB1<*1>: ATQ0 V1 E1 S0=0 -- OK
ttyUSB1<*1>: ATQ0 V1 E1 S0=0 &C1 -- OK
ttyUSB1<*1>: ATQ0 V1 E1 S0=0 &C1 &D2 -- OK
ttyUSB1<*1>: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0 -- OK
ttyUSB1<*1>: Modem Identifier: ATI -- Manufacturer: Micromax
ttyUSB1<*1>: Speed 9600: AT -- OK
ttyUSB1<*1>: Max speed is 9600; that should be safe.
ttyUSB1<*1>: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0 -- OK
WvModem<*1>: Cannot get information for serial port.
ttyUSB2<*1>: ATQ0 V1 E1 -- OK
ttyUSB2<*1>: ATQ0 V1 E1 Z -- OK
ttyUSB2<*1>: ATQ0 V1 E1 S0=0 -- OK
ttyUSB2<*1>: ATQ0 V1 E1 S0=0 &C1 -- OK
ttyUSB2<*1>: ATQ0 V1 E1 S0=0 &C1 &D2 -- OK
ttyUSB2<*1>: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0 -- OK
ttyUSB2<*1>: Modem Identifier: ATI -- Manufacturer: Micromax
ttyUSB2<*1>: Speed 9600: AT -- OK
ttyUSB2<*1>: Max speed is 9600; that should be safe.
ttyUSB2<*1>: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0 -- OK

Found a modem on /dev/ttyUSB1.
Modem configuration written to /etc/wvdial.conf.
ttyUSB1<Info>: Speed 9600; init "ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0"
ttyUSB2<Info>: Speed 9600; init "ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0"

Here is my wvdial.conf file

[Dialer Defaults]
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Modem Type = Analog Modem
Phone = *99***1#
ISDN = 0
;Password =
New PPPD = yes
;Username =
Modem = /dev/ttyUSB1
Baud = 9600

Now when I use wvdial
then my system shows following output and hangs

abhi@abhi:~/Downloads/docomo$ sudo wvdial
[sudo] password for abhi:
--> WvDial: Internet dialer version 1.60
--> Cannot get information for serial port.
--> Initializing modem.
--> Sending: ATZ
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99
+CSQ: 17,99

My service provider does not give a user name and password.
Like this it keeps on repeating above steps and then I keep waiting for a long time.

Now I tried to connect to internet using nm-applet as described on this blog
I had created a new connection in
System-->Preferences-->Mobile Broadband-->Add ----here I had added Tata Docomo

http://ershadk.wordpress.com/2010/03/30 ... untu-9-04/
the connection was visible in nm-applet antenna icon but it failed to dial any thing for internet.

In Windows same modem works correctly.

This time I checked further and found
in

/etc/usb_modeswitch.d

there is no file with

05c6:9000

combination.

Some thing is still missing is that probably this
https://bbs.archlinux.org/viewtopic.php?id=93562

so this time I created a file

So I created

/etc/usb_modeswitch.d/05c6:9000

with following entries

DefaultVendor= 0x05c6
DefaultProduct= 0x9000

TargetVendor= 0x05c6
TargetProduct= 0x9000

MessageContent="5553424312345678000000000000061b000000020000000000000000000000"

But it still failed.After this i did

root@abhi:~# usb_modeswitch -W -c /etc/usb_modeswitch.d/05c6\:9000
Reading config file: /etc/usb_modeswitch.d/05c6:9000

* usb-modeswitch: handle USB devices with multiple modes
* Version 1.1.0 (C) Josua Dietze 2010
* Based on libusb 0.1.12

! PLEASE REPORT NEW CONFIGURATIONS !

DefaultVendor= 0x05c6
DefaultProduct= 0x9000
TargetVendor= 0x05c6
TargetProduct= 0x9000
TargetClass= not set

DetachStorageOnly=0
HuaweiMode=0
SierraMode=0
SonyMode=0
GCTMode=0
MessageEndpoint= not set
MessageContent="5553424312345678000000000000061b000000020000000000000000000000"
NeedResponse=0
ResponseEndpoint= not set
Interface=0x00

InquireDevice enabled (default)
Success check disabled
System integration mode disabled

usb_set_debug: Setting debugging level to 15 (on)
usb_os_find_busses: Found 008
usb_os_find_busses: Found 007
usb_os_find_busses: Found 006
usb_os_find_busses: Found 005
usb_os_find_busses: Found 004
usb_os_find_busses: Found 003
usb_os_find_busses: Found 002
usb_os_find_busses: Found 001
usb_os_find_devices: Found 001 on 008
usb_os_find_devices: Found 001 on 007
usb_os_find_devices: Found 001 on 006
usb_os_find_devices: Found 001 on 005
usb_os_find_devices: Found 001 on 004
usb_os_find_devices: Found 005 on 003
skipped 1 class/vendor specific interface descriptors
usb_os_find_devices: Found 004 on 003
skipped 1 class/vendor specific interface descriptors
skipping descriptor 0xFF
skipped 1 class/vendor specific endpoint descriptors
usb_os_find_devices: Found 003 on 003
skipped 1 class/vendor specific interface descriptors
usb_os_find_devices: Found 002 on 003
usb_os_find_devices: Found 001 on 003
error obtaining child information: Inappropriate ioctl for device
error obtaining child information: Inappropriate ioctl for device
error obtaining child information: Inappropriate ioctl for device
usb_os_find_devices: Found 003 on 002
usb_os_find_devices: Found 001 on 002
error obtaining child information: Inappropriate ioctl for device
usb_os_find_devices: Found 003 on 001
skipping descriptor 0xFF
skipping descriptor 0xB
skipped 2 class/vendor specific endpoint descriptors
skipped 6 class/vendor specific interface descriptors
skipping descriptor 0x25
skipped 1 class/vendor specific endpoint descriptors
skipped 20 class/vendor specific interface descriptors
usb_os_find_devices: Found 001 on 001
error obtaining child information: Inappropriate ioctl for device

Looking for target devices ...
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 413c:8160
searching devices, found USB ID 413c:8162
searching devices, found USB ID 413c:8161
searching devices, found USB ID 0a5c:4500
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 05c6:9000
found matching vendor ID
found matching product ID
searching devices, found USB ID 1d6b:0002
searching devices, found USB ID 0c45:6400
searching devices, found USB ID 1d6b:0002
Found devices in target mode or class (1)
Looking for default devices ...
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 413c:8160
searching devices, found USB ID 413c:8162
searching devices, found USB ID 413c:8161
searching devices, found USB ID 0a5c:4500
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 05c6:9000
found matching vendor ID
found matching product ID
searching devices, found USB ID 1d6b:0002
searching devices, found USB ID 0c45:6400
searching devices, found USB ID 1d6b:0002
Found default devices (1)
Accessing device 003 on bus 002 ...
Using endpoints 0x01 (out) and 0x81 (in)
Not a storage device, skipping SCSI inquiry
USB error: error sending control message: Broken pipe
Error: could not get description string "product"

USB description data (for identification)
-------------------------
Manufacturer: Micromax
Product:
Serial No.: 000000000
-------------------------
Looking for active driver ...
OK, driver found ("usbserial_generic")
OK, driver "usbserial_generic" detached
Setting up communication with interface 0 ...
Trying to send the message to endpoint 0x01 ...
OK, message successfully sent
-> Run lsusb to note any changes. Bye.

But the nm-applet is failing to dial for this modem.

The version installed is

usb_modeswitch --version

* usb-modeswitch: handle USB devices with multiple modes
* Version 1.1.0 (C) Josua Dietze 2010
* Based on libusb 0.1.12

! PLEASE REPORT NEW CONFIGURATIONS !

I use Ubuntu 10.04 my kernel is

2.6.32-24-generic

My ISP does not uses a username and password so wvdial is failing also nm-applet is failing.Both wvdial and nm-applet have failed where as same
But I am able to connect to internet via same modem in Windows and do not give a username and password other than the default phone no to dial which is *99***1#
Let me know if some one has any clue for the same as what next to do?

Posted: **24 Jul 2011, 09:19**

Two things:

1. The device does not change the USB ID after switching. usb_modeswitch needs a way to tell the two modes apart; so you better do not give TargetVendor and TargetProduct but rather the class of the device after switching (initially it's "0x08"):

TargetClass=0xff

This will prevent usb_modeswitch from running twice which it did with your configuration, removing the serial driver again ...

2. In your case it's obvious that ttyUSB1 has a special function: it reports signal quality regularly. So it's really a diagnostic port. You want to try ttyUSB2 for connecting.

wvdial will only check if AT commands are accepted at a serial port. With today's wireless modems this may apply to more than one interface - but only a single one is fit to build up the actual connection.

Posted: **24 Jul 2011, 12:25**

You are the man apart from your suggestions I found that wvdial.conf was also wrong.My net is working.

Let me know

Josh wrote:Two things:

1. The device does not change the USB ID after switching. usb_modeswitch needs a way to tell the two modes apart; so you better do not give TargetVendor and TargetProduct but rather the class of the device after switching (initially it's "0x08"):

TargetClass=0xff

This will prevent usb_modeswitch from running twice which it did with your configuration, removing the serial driver again ...

I want to understand above part of your message.I modified the
/etc/usb_modeswitch.d/05c6:9000 to following

DefaultVendor= 0x05c6
DefaultProduct=0x9000

#TargetVendor= 0x05c6
#TargetProduct= 0x9000
TargetClass=0xff

CheckSuccess=20

MessageContent="5553424312345678000000000000061b000000020000000000000000000000"

Josh wrote: 2. In your case it's obvious that ttyUSB1 has a special function: it reports signal quality regularly. So it's really a diagnostic port. You want to try ttyUSB2 for connecting.

wvdial will only check if AT commands are accepted at a serial port. With today's wireless modems this may apply to more than one interface - but only a single one is fit to build up the actual connection.

and modified the wvdial.conf to following

[Dialer Defaults]
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Modem Type = USB Modem
Phone = *99***1#
ISDN = 0
Username = " "
Password = " "
Init1 = ATZ
Init3 = AT+CGDCONT=1,"IP","TATA.DOCOMO.INTERNET"
Modem = /dev/ttyUSB2
Baud = 9600
Auto DNS = 1
Dial Command = ATDT
Carrier Check = yes
Stupid Mode = 1

now when I executed

root@abhi:~# usb_modeswitch -W -c /etc/usb_modeswitch.d/05c6\:9000

I got

Reading config file: /etc/usb_modeswitch.d/05c6:9000

* usb-modeswitch: handle USB devices with multiple modes
* Version 1.1.0 (C) Josua Dietze 2010
* Based on libusb 0.1.12

! PLEASE REPORT NEW CONFIGURATIONS !

DefaultVendor= 0x05c6
DefaultProduct= 0x9000
TargetVendor= not set
TargetProduct= not set
TargetClass= 0xff

DetachStorageOnly=0
HuaweiMode=0
SierraMode=0
SonyMode=0
GCTMode=0
MessageEndpoint= not set
MessageContent="5553424312345678000000000000061b000000020000000000000000000000"
NeedResponse=0
ResponseEndpoint= not set
Interface=0x00

InquireDevice enabled (default)
Success check enabled, max. wait time 20 seconds
System integration mode disabled

usb_set_debug: Setting debugging level to 15 (on)
usb_os_find_busses: Found 008
usb_os_find_busses: Found 007
usb_os_find_busses: Found 006
usb_os_find_busses: Found 005
usb_os_find_busses: Found 004
usb_os_find_busses: Found 003
usb_os_find_busses: Found 002
usb_os_find_busses: Found 001
usb_os_find_devices: Found 001 on 008
usb_os_find_devices: Found 001 on 007
usb_os_find_devices: Found 001 on 006
usb_os_find_devices: Found 001 on 005
usb_os_find_devices: Found 001 on 004
usb_os_find_devices: Found 005 on 003
skipped 1 class/vendor specific interface descriptors
usb_os_find_devices: Found 004 on 003
skipped 1 class/vendor specific interface descriptors
skipping descriptor 0xFF
skipped 1 class/vendor specific endpoint descriptors
usb_os_find_devices: Found 003 on 003
skipped 1 class/vendor specific interface descriptors
usb_os_find_devices: Found 002 on 003
usb_os_find_devices: Found 001 on 003
error obtaining child information: Inappropriate ioctl for device
error obtaining child information: Inappropriate ioctl for device
error obtaining child information: Inappropriate ioctl for device
usb_os_find_devices: Found 010 on 002
usb_os_find_devices: Found 001 on 002
error obtaining child information: Inappropriate ioctl for device
usb_os_find_devices: Found 003 on 001
skipping descriptor 0xFF
skipping descriptor 0xB
skipped 2 class/vendor specific endpoint descriptors
skipped 6 class/vendor specific interface descriptors
skipping descriptor 0x25
skipped 1 class/vendor specific endpoint descriptors
skipped 20 class/vendor specific interface descriptors
usb_os_find_devices: Found 001 on 001
error obtaining child information: Inappropriate ioctl for device

Looking for target devices ...
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 413c:8160
searching devices, found USB ID 413c:8162
searching devices, found USB ID 413c:8161
searching devices, found USB ID 0a5c:4500
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 05c6:9000
found matching vendor ID
found matching product ID
searching devices, found USB ID 1d6b:0002
searching devices, found USB ID 0c45:6400
searching devices, found USB ID 1d6b:0002
Found devices in target mode or class (1)
Looking for default devices ...
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 413c:8160
searching devices, found USB ID 413c:8162
searching devices, found USB ID 413c:8161
searching devices, found USB ID 0a5c:4500
searching devices, found USB ID 1d6b:0001
searching devices, found USB ID 05c6:9000
found matching vendor ID
found matching product ID
searching devices, found USB ID 1d6b:0002
searching devices, found USB ID 0c45:6400
searching devices, found USB ID 1d6b:0002
Found default devices (1)
All devices in target class mode. Nothing to do. Bye.

and wvdial

wvdial
--> WvDial: Internet dialer version 1.60
--> Cannot get information for serial port.
--> Initializing modem.
--> Sending: ATZ
OK
--> Sending: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
OK
--> Sending: AT+CGDCONT=1,"IP","TATA.DOCOMO.INTERNET"
AT+CGDCONT=1,"IP","TATA.DOCOMO.INTERNET"
OK
--> Modem initialized.
--> Sending: ATDT*99***1#
--> Waiting for carrier.
ATDT*99***1#
CONNECT 7200000
--> Carrier detected. Starting PPP immediately.
--> Starting pppd at Sun Jul 24 15:41:21 2011
--> Pid of pppd: 3373
--> Using interface ppp0
--> pppd: �[7f]
--> pppd: �[7f]
--> pppd: �[7f]
--> pppd: �[7f]
--> pppd: �[7f]
--> pppd: �[7f]
--> local IP address 192.168.181.10
--> pppd: �[7f]
--> remote IP address 192.168.181.64
--> pppd: �[7f]
--> primary DNS address 192.168.181.256
--> pppd: �[7f]
--> secondary DNS address 192.168.181.210
--> pppd: �[7f]

then I got in /var/log/messages

and some where /var/log/messages

Jul 24 15:41:21 abhi pppd[3373]: pppd 2.4.5 started by root, uid 0
Jul 24 15:41:21 abhi pppd[3373]: Using interface ppp0
Jul 24 15:41:21 abhi pppd[3373]: Connect: ppp0 <--> /dev/ttyUSB2
Jul 24 15:41:21 abhi pppd[3373]: CHAP authentication succeeded
Jul 24 15:41:21 abhi pppd[3373]: CHAP authentication succeeded
Jul 24 15:41:21 abhi kernel: [ 2833.252141] PPP BSD Compression module registered
Jul 24 15:41:22 abhi kernel: [ 2833.263961] PPP Deflate Compression module registered
Jul 24 15:41:24 abhi pppd[3373]: Could not determine remote IP address: defaulting to 192.168.181.64
Jul 24 15:41:24 abhi pppd[3373]: local IP address 192.168.181.10
Jul 24 15:41:24 abhi pppd[3373]: remote IP address 192.168.181.64
Jul 24 15:41:24 abhi pppd[3373]: primary DNS address 192.168.181.256
Jul 24 15:41:24 abhi pppd[3373]: secondary DNS address 192.168.181.210

I have replaced the IP addresses which I got by class C ones but all above were Internet ones.(For obvious reasons)

This really worked like a charm.But I could not understand why
1) Why we needed to use TargetClass. What difference did it made?
2) /dev/ttyUSB2 how did you figured that out that it wont be /dev/ttyUSB1 or /dev/ttyUSB0 ?

I am right now able to post this message from the modem by the changes you suggested.Thanks to you but do let me know what these changes mean.

Posted: **25 Jul 2011, 19:01**

The TargetClass is needed for usb_modeswitch to check the mode the device is in. It does change its setup, but it does not change its USB ID like other devices do.

usb_modeswitch should do nothing if the device was switched to modem already. One of the things it would do is remove the driver to gain access. You don't want that after having loaded the serial driver. So this should only happen in install mode.

Well then - how do we check the mode? We are looking at the "InterfaceClass" of the first device interface. If it is "8" we have the install mode; if we have "255" (0xff in hexadec.) we have the modem mode.

The thing with ttyUSB2 is easy. I know that in most cases there are diagnostic ports that may accept AT commands but are not fit for connecting.

If you have two "AT ports" and one is not working, the other one is supposed to be right ...

BTW, now you can make the whole thing automatic. Just add a line to
/lib/udev/rules.d/40-usb_modeswitch.rules (the exact name may differ),
containing the IDs of your device.
You can copy and adapt one of the existing lines, it's really easy.

Posted: **26 Jul 2011, 04:19**

Ok udev is a good suggestion.The device I reported is MicroMax MMX 372 G USB modem.
The sim card can be of various service providers.So in my case it was Tata Docomo some one might have BSNL,AIRTEL,

I want to read more about the small small details like you mentioned TargetClass there are many other such variables when it comes to USB modems.
Also I want to read more about AT commands.

I was able to create a correct wvdial.conf file by reading on internet various AT commands from here and there and produced some thing which worked for me.wvdialconf command did not generated a fully working copy for me specially Init3 set of commands was what I had added myself where I had to provide access point name etc.I was browsing your site for more details like

usb_modeswitch -W -c config_file

what does the respective output means. Let me know where can I understand more finer details with respect to such devices.It is out of personal interest so want to read and understand more.

Posted: **26 Jul 2011, 23:20**

What specific output are you referring to? It's pretty long ...

USB_ModeSwitch

using Tata Docomo USB modem (05c6:9000) with Ubuntu 10.04

using Tata Docomo USB modem (05c6:9000) with Ubuntu 10.04