Using Pantech UML290 on Ubuntu Linux 11.04 (Natty Narwhal)

Update: The method used in this article requires WvDial. If you want to use plain old pppd instead, please see this article.
Update: If this method does not work for you and fails with the error message mentioned in this comment, then please try the solution described in this comment.

Ubuntu Linux 11.04 (Natty Narwhal) was released today and I am very excited by the new Unity interface. Upgrading from 10.10 to 11.04 was a breeze and went without a hitch. The only disappointment so far has been the modified mobile broadband configuration interface. As described in this post, in order to use a Pantech UML290 modem on Verizon's 4G LTE network, one needs to enter a custom APN value of "vzwinternet". It turns out that the option to enter a custom APN value is no longer available in 11.04. Hence, I was unable to use the same trickery to get the modem to work with 11.04.

But not all is lost as there are always many ways to do the same thing on Linux (which is one of the reasons why I love it so much). It turns out that one can use wvdial to connect to the internet via this modem over Verizon's 4G LTE modem. I utilized the wvdial.conf file that was posted here as a starting point and made minor modifications to it. My wvdial.conf file is listed below (replace "858#######" with your modem's phone number):

[Dialer Defaults]
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Init3 = AT+CGDCONT=3,"IPV4V6","vzwinternet","0.0.0.0",0,0
Modem Type = USB Modem
Stupid Mode = 1
New PPPD = yes
Dial Command = atdt
Carrier Check = no
ISDN = 0

[Dialer Verizon4GLTE]
Modem = /dev/ttyACM0
Baud = 100000000
Phone = *99***3#
Username = 858#######@vzw4g.com
Password = vzw

Place the above text into the file named /etc/wvdial.conf (assuming that you have already installed the wvdial package). After this you can connect to the 4G network by typing the following command (output from my computer is shown below for reference):

[pagey@pagey-ideapad]$ sudo wvdial Verizon4GLTE
[sudo] password for pagey: 
--> WvDial: Internet dialer version 1.61
--> Cannot get information for serial port.
--> Initializing modem.
--> Sending: ATZ
ATZ
OK
--> Sending: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
OK
--> Sending: AT+CGDCONT=3,"IPV4V6","vzwinternet","0.0.0.0",0,0
AT+CGDCONT=3,"IPV4V6","vzwinternet","0.0.0.0",0,0
OK
--> Modem initialized.
--> Sending: atdt*99***3#
--> Waiting for carrier.
atdt*99***3#
CONNECT 100000000
--> Carrier detected.  Starting PPP immediately.
--> Starting pppd at Thu Apr 28 16:17:58 2011
--> Pid of pppd: 13561
--> pppd: e[7f]
--> Using interface ppp0
--> pppd: e[7f]
--> pppd: e[7f]
--> pppd: e[7f]
--> pppd: e[7f]                    
--> pppd: e[7f]
--> local  IP address 10.190.171.236
--> pppd: e[7f]
--> remote IP address 10.64.64.64
--> pppd: e[7f]
--> primary   DNS address 69.78.80.231
--> pppd: e[7f]
--> secondary DNS address 69.78.134.231
--> pppd: e[7f]

I am sure there are better ways to do this but the above procedure works for now till I figure out a better way.