Hello everyone,
I just recently purchased a 411UAHR and tried to use a known working Sierra MC8700 card PCIE-e card with it, but to no avail.
I get as far as "authenticated" but then it disconnects and redials the ppp connection.
Here is my info:
My 3g provider is Bell and I am in Ontario Canada.

/interface ppp-client
add add-default-route=yes allow=pap,chap,mschap1,mschap2 apn=inet.bell.ca \
data-channel=3 dial-command=ATDT dial-on-demand=no disabled=no \
info-channel=2 keepalive-timeout=10 max-mru=1500 max-mtu=1500 modem-init=\
"" mrru=disabled name=ppp-out1 null-modem=no password="" phone=*99# pin=\
"" port=usb2 profile=default use-peer-dns=yes user=""

I know that I have the right APN, and phone number, but I am not 100% on the data/info channels and if there are any modem initialization strings required.

Any suggestions would be greatly appreciated.

So I just solved my problem. I used this initialization string: at+cgdcont=1,"IP","inet.bell.ca"
And removed the entry from "APN"