Multi-WAN bonding across different media

I've recently been thinking again about a product that Viprinet provide, basically they've got a pair of routers, one that lives in a datacentre, Their VPN Multichannel Hub and the on-site hardware, their VPN multichannel routers

They've also got a bunch of interface cards (like HWICs) for 3G, UMTS, Ethernet, ADSL and ISDN adapters.

Their main spiel seems to be bonding across different media. It's something that I'd really like to use for a couple of projects, but their pricing is really quite extreme, the hub is about 1-2k, the routers are 2-6k, and the interface modules are 200-600 each.

So, what I'd like to know is, is it possible with a couple of stock Cisco routers, 28xx or 18xx series, to do something similar, and basically connect a bunch of different WAN ports, but have it all presented neatly as one channel back to the internet, with seamless (or nearly) failover if one of the WAN interfaces should fail.

Basically, If i got 3x 3G to ethernet modems, and each on a different network, I'd like to be able to loadbalance/bond across all of them, without having to pay Viprinet for the privilege.

Does anyone know how I'd go about configuring something for myself, based around standard protocols (or vendor specific ones), but without actually having to buy the Viprinet hardware?

With Cisco, I would go either for some CEF load sharing or Policy Based Routing (now called performance routing).

I never tried CEF load-sharing on 3G (only on frame-relay leased lines), but setting three tunnels, each via a different card, to an endpoint (which will be your gateway) and with three equal-cost routes to that endpoint could work. In my setup the PE router was the endpoint, so no tunnel was needed.

Cisco has some documentation about it, and load-sharing can be set either per-packet or per-destination.

From the troubleshooting guide:

7200-1.3(config)#interface fast 0/0

7200-1.3(config-if)#ip load-sharing ? 
  per-destination  Deterministic distribution 
  per-packet       Random distribution 

7200-1.3(config-if)#ip load-sharing per-packet

Ivan Pepelnjak has also two entries on his blog regarding CEF load-sharing that are worth reading.

Regarding Policy Based Routing, I also operate a customer network of small sites that are connected to a central hub via various tubes. Each spoke has a FR leased line, a dsl internet access (with IPSec over the internet) and a satellite link.

All links goes to one of our PE router (be it frame, internet or satellite) and then over mpls (in different vpns) to the central hub, where each vpn terminate in a VRF (vrf-lite here, no mpls) on the CE router. Each vpn is then routed to a vlan.

The various customer applications are routed (by destination IP or L4 port) on the spokes over the different links. Voice goes over satellite, mail and some other over the dsl link, and core apps over the leased line.

In case of link failure, traffic is re-routed over the other links.

Cisco wiki has an interesting article about PfR.

On a side note, if you are going to go the 3G way, pay attention to the providers you are choosing as the 3G Node-Bs are not going to have a lot of bandwidth (just a few E1s usually) and you may not get the expected bandwidth. Pick different service providers, and not from one who is reselling another's service.

I think I understand what you're asking for. I've been very happy with the Elfiq line of multi-WAN load balancers. In my current application, I'm balancing MPLS, fixed-wireless, T1, DSL and 3G USB at one location. The 3G support is good and well-documented. This setup handle inbound and outbound load balancing.

The Elfiq sits in front of a Cisco ASA firewall and is transparent to my L2L VPN connections.

Management console

Load-balancing algorithm selection