The above picture shows the ZTE AC8710 modem I got along with my connection. It’s pretty easy to install it in windows, you even do not need to have the driver CD. Just plug in the modem, at first it will be detected as a storage device. The storage device have the modem driver built into it, so an autoplay will install the modem driver and reliance net connecting suite on to your windows.

The feature of USB devices to have multiple configuration (storage device / modem) can cause hell lot of confusions, while using it in linux. Let me explain,

First I inserted my USB modem on to the port in Fedora 10 installed box, below is the kernel message and command output of ‘lsusb’ ,

======= Kernel message ====

usb 3-1: new full speed USB device using uhci_hcd and address 7
usb 3-1: New USB device found, idVendor=19d2, idProduct=fff6
usb 3-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 3-1: Product: USB Storage
usb 3-1: Manufacturer: ZTE, Incorporated
usb 3-1: SerialNumber: 000000000002
usb 3-1: configuration #1 chosen from 1 choice
scsi6 : SCSI emulation for USB Mass Storage devices
usb-storage: device found at 7
usb-storage: waiting for device to settle before scanning
usb-storage: device scan complete
scsi 6:0:0:0: CD-ROM            ZTE      USB Storage FFF1 2.31 PQ: 0 ANSI: 2
sr1: scsi-1 drive
sr 6:0:0:0: Attached scsi CD-ROM sr1
sr 6:0:0:0: Attached scsi generic sg3 type 5
sr1: CDROM (ioctl) error, command: Get configuration 46 00 00 00 00 00 00 00 20 00
sr: Sense Key : No Sense [current]
sr: Add. Sense: No additional sense information

===== lsusb =======

[root@localhost win]# lsusb
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 009: ID 19d2:fff6 ONDA Communication S.p.A.
Bus 003 Device 006: ID 1058:0704 Western Digital Technologies, Inc.
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
[root@localhost win]#

The kernel message says, it detected the modem as a storage device. Exactly as a SCSI cdrom device /dev/sr1. The lsusb output gives the device id and vendor id as 19d2 and fff6 respectively. Mean my fedora 10 box was able to detect configuration 1 (storage) but not configuration 2 ( Modem ) of the USB device.

I was quite sure that I do not have the device driver required to detect the modem in my list of kernel modules. After some search, I found the kernel module ‘usbserial.ko’ which is needed to make the modem ZTE AC8710 work.

Luckily, before trying usbserial I found linux device driver pack for BSNL EVDO connection from the homepage of the USB modem provider. Locate it here,

http://www.ztemt.com.cn/ennewzte/service/ziliao.action

The driver from the above link is for ZTE AC8700 and not AC8710, still I made up my mind to try. The driver pack consists below files,

ztemtEVDO-1.1-8-i386-ubuntu804.deb
ztemtEVDO-1.1-8.i586-fedora9.rpm
ztemtEVDO-1.1-8.i586-suse103.rpm

I choose fedora9 for my fedora10 installation, the installation went fine. The installation adds a service named ”ztemtvcdromd” to your runlevel. What does service ztemtvcdromd do ?

* Installs udev rules needed to detect the USB EVDO modem

* Inserts USB module ztemt.ko

* Starts the process /usr/sbin/ztemtvcdromd

I started the service all worked well, except the loading of the kernel module ztemt.ko. I found that ztemt.ko was not compiled for my version of kernel 2.6.29.

Replugged the modem. Once again I went through the kernel messages and lsusb output. To my surprise I found my product id changed from 0xfff6 to 0xfff1 with below messages from kernel,

======= Kernel message ====

usb 3-1: new full speed USB device using uhci_hcd and address 8
usb 3-1: New USB device found, idVendor=19d2, idProduct=fff6
usb 3-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 3-1: Product: USB Storage
usb 3-1: Manufacturer: ZTE, Incorporated
usb 3-1: SerialNumber: 000000000002
usb 3-1: configuration #1 chosen from 1 choice
scsi7 : SCSI emulation for USB Mass Storage devices
usb-storage: device found at 8
usb-storage: waiting for device to settle before scanning
usb-storage: device scan complete
scsi 7:0:0:0: CD-ROM            ZTE      USB Storage FFF1 2.31 PQ: 0 ANSI: 2
sr1: scsi-1 drive
sr 7:0:0:0: Attached scsi CD-ROM sr1
sr 7:0:0:0: Attached scsi generic sg3 type 5
usb 3-1: USB disconnect, address 8
usb 3-1: new full speed USB device using uhci_hcd and address 9
usb 3-1: New USB device found, idVendor=19d2, idProduct=fff1
usb 3-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
usb 3-1: Product: ZTE CDMA Tech
usb 3-1: Manufacturer: ZTE, Incorporated
usb 3-1: configuration #1 chosen from 1 choice

===== lsusb =======

[root@localhost ztemtEVDO]# lsusb
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 009: ID 19d2:fff1 ONDA Communication S.p.A.
Bus 003 Device 006: ID 1058:0704 Western Digital Technologies, Inc.
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
[root@localhost ztemtEVDO]#

The kernel was now able to detect the second USB configuration of the device with vendor id 0×19d2 and 0xfff1, which is suppose our CDMA modem. Now the final thing to be done is load the kernel module ztemt.ko. I found the source code for the kernel module in the following location, which came along with the driver package provided by the vendor,

/usr/local/bin/ztemtEVDO/usb-serial.tar.gz

I recompiled it for my version of kernel (2.6.29) and loaded ztemt.ko. Again replugged the USB modem. But couldn’t find the device getting registered in /dev. So I went through the source code of ztemt.ko and found it similar to native driver provided by the linux kernel for USB serial modems (usbserial.ko)

So I decided to go with usbserial.ko,

* Restarted the service ztemtvcdromd

* Ensured that the driver ztemt.ko is not loaded

* Took vendor id and device id from lsusb output, which is 19d2:fff1 for me.

* Executed command ‘modprobe usbserial vendor=0×19d2 product=0xfff1′

Now I got the below kernel message,

usbserial_generic 3-1:1.0: generic converter detected
usb 3-1: generic converter now attached to ttyUSB0
usbserial_generic 3-1:1.1: generic converter detected
usb 3-1: generic converter now attached to ttyUSB1
usbserial_generic 3-1:1.2: generic converter detected
usb 3-1: generic converter now attached to ttyUSB2
usbserial_generic 3-1:1.3: generic converter detected
usb 3-1: generic converter now attached to ttyUSB3
usbserial_generic 3-1:1.4: generic converter detected
usb 3-1: generic converter now attached to ttyUSB4

It shows that my modem is registered as /dev/ttyUSB0, success!!

I wrote below wvdial script in /etc/wvdial.conf,

[Dialer Defaults]
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Modem Type = Analog Modem
ISDN = 0
Username = xxxxxx # Your 10 digit phone number
Init1 = ATZ
Password = xxxxxxx # Your 10 digit phone number
Modem = /dev/ttyUSB0
Baud = 3686400
Phone = #777
stupid mode = 1

Now it is all set to establish the connection, executed command ‘wvdial’ as root. I got connected to the internet Hurrreh!!,

--> WvDial: Internet dialer version 1.60
--> Cannot get information for serial port.
--> Initializing modem.
--> Sending: ATZ
ATZ
OK
--> Sending: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
OK
--> Modem initialized.
--> Sending: ATDT#777
--> Waiting for carrier.
ATDT#777
CONNECT
--> Carrier detected.  Starting PPP immediately.
--> Starting pppd at Thu Apr  9 11:45:27 2009
--> Pid of pppd: 9389
--> Using interface ppp0
--> local  IP address 115.240.95.59
--> remote IP address 220.224.141.129
--> primary   DNS address 202.138.97.193
--> secondary DNS address 202.138.96.2

Now copy your primary and secondary nameservers to /etc/resolv.conf,

[root@localhost ztemtEVDO]# cat /etc/resolv.conf
nameserver 202.138.96.2
nameserver 202.138.97.193

Now try any browser and access your websites or download with Reliance netconnect broadband+ EVDO connection On an average I got 60kBps download speed.

Later on I edited service script /etc/init.d/ztemtvcdromd to remove ‘/sbin/modprobe ztemt.ko’ and ‘/sbin/rmmod ztemt.ko’ from start and stop cases respectively. Then added lines ‘/sbin/modprobe usbserial vendor=0×19d2 product=0xfff1′ and ‘/sbin/rmmod usbserial’ to start and stop cases respectively.

FYI: Product ID may differ in your case, so be careful in noting it down from ‘dmesg’ or ‘lsusb’ output.

Issues detected:

Reconnecting second time to internet doesn’t work once you disconnect your connection by using Ctrl-C to wvdial. Re-inserting the modem to USB port will solve it

Contact: asalamr@gmail.com

* No simultaneous access to the dsp device

* When switching from X to tty background audio crashes

So remove pulse audio and fall back to ALSA,

yum remove pulseaudio alsa-plugins-pulseaudio