I installed ubuntu 14.04.I purchased the dongle Huawei 3G E3531 & it runs fine in windows.But when i configured in ubuntu using network connections it doesn't connect.
Please provide step by step procedure to configure this modem in Ubuntu 14.04.

This isn't the place to come for "step-by-step" how-to's. There have been many, MANY answers to questions almost identical to this, which you can easily find with a search on LQ, or via Google.

The Huawei devices need to be 'flipped' from CD-ROM/block storage devices, to modems, before they can be used. Install the usb_modeswitch program through your software manager, and run it. Then configure and use the device.

I think here many of them are experts.It is better to hear from them directly.When read different threads i don't know which method to follow.Also i am completely new to linux.Kindly suggest required steps.

Pick one and try it. If it doesn't work, try another.
...yet you installed Ubuntu and have been registered here for TWO YEARS at this point. Hardly 'new.
Go back an re-read my original reply, and do what it told you. I gave you 'required steps'. Follow them.

You need information...

The modem is converted from a CD device to a modem with the program USB_ModeSwitch, which you should have in your Ubuntu installation. Check that this is the case. If USB_ModeSwitch is working the device should be switched automatically at plug-in.

You need to use the Internet to find the ID for the modem. As an example, for my Huawei E1752 the ID is 12d1:1446. The internet tells me the ID changes to 12d1:1001 when switched.

Then you need to plug in the modem and run the command "lsusb" to see how the device is identified. Even if the modem is switching, there may be other reasons you're not connecting.

The place to go for information and help is the Draisberghof site and their forum.

http://www.draisberghof.de/usb_modeswitch/

TBOne is right, there are many threads on this topic, and he gets tired of answering the same questions over and over. Help comes to those who help themselves.

1 members found this post helpful.

I tried following
lsusb -v -d 12d1:1506

Bus 001 Device 002: ID 12d1:1506 Huawei Technologies Co., Ltd. E398 LTE/UMTS/GSM Modem/Networkcard
Couldn't open device, some information will be missing
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 2 Communications
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x12d1 Huawei Technologies Co., Ltd.
idProduct 0x1506 E398 LTE/UMTS/GSM Modem/Networkcard
bcdDevice 1.02
iManufacturer 1
iProduct 2
iSerial 0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 237
bNumInterfaces 6
bConfigurationValue 1
iConfiguration 0
bmAttributes 0x80
(Bus Powered)
MaxPower 500mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 3
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 3
bInterfaceProtocol 1
iInterface 0
** UNRECOGNIZED: 05 24 00 10 01
** UNRECOGNIZED: 04 24 02 02
** UNRECOGNIZED: 05 24 01 00 00
** UNRECOGNIZED: 05 24 06 00 00
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 5
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 3
bInterfaceProtocol 22
iInterface 5
** UNRECOGNIZED: 05 24 00 10 01
** UNRECOGNIZED: 06 24 1a 00 01 1f
** UNRECOGNIZED: 0c 24 1b 00 01 00 04 10 14 dc 05 20
** UNRECOGNIZED: 0d 24 0f 07 0f 00 00 00 ea 05 03 00 01
** UNRECOGNIZED: 05 24 06 01 01
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x85 EP 5 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0010 1x 16 bytes
bInterval 9
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 1
bNumEndpoints 3
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 3
bInterfaceProtocol 22
iInterface 6
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x85 EP 5 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0010 1x 16 bytes
bInterval 9
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x84 EP 4 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x03 EP 3 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 2
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 3
bInterfaceProtocol 3
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x86 EP 6 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x04 EP 4 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 3
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 3
bInterfaceProtocol 2
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x87 EP 7 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x05 EP 5 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 4
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk-Only
iInterface 4
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x88 EP 8 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x06 EP 6 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 5
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk-Only
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x89 EP 9 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x07 EP 7 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 1

---------- Post added 06-04-14 at 03:31 AM ----------

Then this
sudo usb_modeswitch -W -I -v 12d1 -p 1506 -M 55534243123456780000000000000011062000000101000100000000000000
Take all parameters from the command line


* usb_modeswitch: handle USB devices with multiple modes
* Version 2.1.1 (C) Josua Dietze 2014
* Based on libusb1/libusbx

! PLEASE REPORT NEW CONFIGURATIONS !

DefaultVendor= 0x12d1
DefaultProduct= 0x1506
MessageContent="55534243123456780000000000000011062000000101000100000000000000"
NeedResponse=0

InquireDevice=1

Look for default devices ...
found USB ID 12d1:1506
vendor ID matched
product ID matched
found USB ID 1d6b:0002
found USB ID 0e0f:0002
found USB ID 0e0f:0003
found USB ID 1d6b:0001
Found devices in default mode (1)
Access device 002 on bus 001
Current configuration number is 1
Use interface number 0
Use endpoints 0x02 (out) and 0x82 (in)
Error: can't use storage command in MessageContent with interface 0;
interface class is 2, expected 8. Abort

Finally unable to connect to internet.

When I had a dongle, it got mounted as CD-ROM. When I installed the software from the CD-ROM, I was
able to connect to internet beacuse it got detected as a modem.

I think you are missing the driver for your modem i.e. it is not installed. Please check if there is
an installer for Linux when the dongle is mounted. If it does not get mounted, reply so.

What usb_modeswitch does that it switches your dongle mode to modem so that you can dialup. But may be
it is not working because the driver is missing.

I installed driver.

...and....
...and....
Did you read and understand what you were told in the VERY FIRST REPLY????.

AGAIN: You need to load the usb_modeswitch program. After you load it, RUN IT. Then, your device will be a modem, and you will be able to use whatever network manager you want to configure your connection. Simple.

usb_modeswitch is in your software manager. Run it, search for it, and click INSTALL. That's it.