Just now I configured Huawei EC-121 USB Datacard provided by Reliance on Ubuntu like my BSNL EvDO card using wvdial. It works!
I think its time for Reliance to put up a page for Gnu/Linux users on their hand book.

Here are the steps for configuring the card:
To configure wvdial with new modem run the following command in Terminal
#wvdialconf /etc/wvdial.conf
Your /etc/wvdial.conf will have the following entries.
# cat /etc/wvdial.conf[Dialer Defaults]
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Modem Type = Analog Modem
; Phone =
ISDN = 0
; Username =
Init1 = ATZ
; Password =
Modem = /dev/ttyUSB0
Baud = 460800
Change the target phone no. to #777 and Username and password need to be set to the Reliance 10 digit number.
And you require an another magical line added to this file. i.e.
Stupid Mode = 1
Once this is done run the following command to get connected.
# wvdial
Enjoy working with Reliance Datacard…
You might want to read my other articles related to USB Datacards:



