Multiple USB Dongles can used via a USB hub - however the benefits of bonding multiple 3G are small, as you'll typically be contending with yourself and so there will be little or no added bandwidth.
Using multiple dongles with SIMs from different providers may provide extra resilience in the case of one having a problem.
=Basic 3G Config=
= Config with Tunneled IPv6 Fallback ==
If using AAISP, then the options for IPv6 routing on the [[:Category:Control Pages|Control Pages]] allow an IPv6 block to be routed to a tunnel endpoint if the main routing (ie ADSL/FTTC) goes down. This means IPv6 can be routed to the 3G dongle if the main broadband(s) go down. The MTU will be limited though.
3G profiles - turning the dongle off outside of office hours=
Sometimes we don't want the dongle to be online 24x7 and want it turned off outside of office hours.
The 3G profile is then active during office hours, but it will become active if both of the ADSL lines are down outside of office hours.
Ping test example of falling back =
Here we ping an IP on the LAN, behind the FB2700, and get the ADSL router to re-sync. The ADSL went down, the 3G kicked in with only a single ping lost, then shortly after the ADSL came back on and took over the routing again.
You can tell when the swap over happened as the latency increases and then decreases again when the DSL came back online
Telnet Commands =
Will reset the usb controller and re-detect everything from scratch: