After looking at the logs, he told that this device is probably not a qmi device. Finally I contacted Bjorn(author of qmi-wwan.c in linux tree). Although it loaded the qmi driver, /dev/cdc-wdm0 was not usable.
I forced QMI module to load driver for this device by editing the kernel. What surprised me was how can usb modem get an ethernet connection? how? I went to linux, ubuntu forums, no help! I assumed that kernel wrongly detected this device. usbcore: registered new interface driver cdc_etherĮth0 Link encap:Ethernet HWaddr 34:4b:50:b6:ab:3c usb 2-1: New USB device found, idVendor=19d2, idProduct=1408 usb 2-1: new high-speed USB device number 5 using s5p-ehci usb 2-1: USB disconnect, device number 4 cdrom: Uniform CD-ROM driver Revision: 3.20 sd 0:0:0:1: Attached SCSI removable disk scsi 0:0:0:1: Direct-Access ZTE MMC Storage 2.31 PQ: 0 ANSI: 2 scsi 0:0:0:0: CD-ROM CWID USB SCSI CD-ROM 2.31 PQ: 0 ANSI: 2 usbcore: registered new interface driver usb-storage usbcore: registered new interface driver libusual usb 2-1: Product: ZTE WCDMA Technologies MSM usb 2-1: New USB device strings: Mfr=2, Product=3, SerialNumber=4 usb 2-1: New USB device found, idVendor=19d2, idProduct=1225 usb 2-1: new high-speed USB device number 4 using s5p-ehci cdc_ether module picks up this device and creates an ethernet connection. Then udev kicks in and mode switches it to 1408 from 1225. When you connect the device it is detected as usb storage device. If you provide a good looking GUI with connect/disconnect button and not say how it works, how can it satisfy a linux guy The documentation provided by zte is (in)dispensable for the fact that this product is not listed anywhere in their website. The modem is basically from ZTE, ZTE MF825A.
I have this ARM chromebook and who will provide that piece of software with connect and disconnect button! My problem with this usb device was I couldn’t get this working on linux! Yes, they did provide software setup for windows/linux, all those were x86 based. I recently purchased airtel 4G internet for its reasonable cost and high speed. You get a constant download speed of 10 Mbps here in b'lor.