Multiple internet connections on a small network?

[Audigex]

Hey guys

A fairly quick question, but I'll probably make it into a long-winded description, as always, bear with me

Basically I want to have a small network comprising both wired and wireless elements, and have multiple internet connections available through the network.

It's mostly for learning purposes, but I figure it could come in handy in some ways.

Essentially I've got:
ADSL - (Wireless Router/Switch/ADSL modem) - other computers

And another laptop, which has a 3g connection and can also connect to the wireless network. To use this 3g network, is it as simple as turning on "inernet connection sharing" or whatever it's called?

Also, how would that work with there now being two seperate connections running? Would computers use the fastest link, just the router, whatever link is available, etc? Would this work the same if I had a cable modem and an ADSL modem on the same network?

Finally, if (in theory, and assuming it wasn't against the TOS of the ISPs) I had two ADSL modems in neighbouring houses, and their wireless networks were the same settings (ie, the same wireless network), would this work the same?

The latter is more of a useful excercise for us, since we've got two university buildings nearby, using the same network, but each have different downtime for "scheduled maintenance" - we were considering building some resiliance of our own into the network by combining both building's connection, so we can use whichever's is up.

Okay, that ends my long-winded explanation... thanks for any input

 

[kerrgreg]

Ok, first questio i will answer is that making a laptop with 3g share its connection to the rest of the network will be hard and it will be slow (of course) and in most case's it wont work at all often if a windows pc's wont connect properly if you use both wireless and another network like a 3g card.

You cant effectively have two routers on the same network since they will both be trying to do DHCP and there will be no way for the two routers two decide which is going to be a designated router (if your routers support that) you would need to use some sort of firewall with load balancing or a PFsence or other open-source firewall/ routing box that could manage them.

As for the separate uni wireless networks unless you can get the uni to allow wireless bridging otherwise only individual pc's will be able to connect via their wireless

think ive covered it all there.

 

[Dreadhead]

There are Draytek routers which allow you to plug a 3G dongle into them. When bandwidth is maxed on the ADSL, or the ADSL drops out then the 3G dongle kicks in. That may cover what you are looking for.

Generally though the 3G dongle will add nothing to a normal ADSL connection. As said in the previous post the 3G dongle will be slow and usually the pings are fairly high.