I've got two internet connections at home: DSL and satellite. The DSL connection has bad bandwidth (1.5 Mbps) but very low latency; the satellite connection is the opposite (good bandwidth, terrible latency). I use them for different purposes: the DSL connection works well for SSH connections and other remote-access situations where latency is more important; satellite is for video (Netflix, etc.) where bandwidth is more important.
Is there a router than can gang these two networks together, letting me intelligently route traffic over a given WAN? That is, I'd like to define some rules like "send all SSH traffic via WAN 1", "send HTTP via WAN 2", etc. Idaeally, I'd like to also route on IP address ("send HTTP to a.b.c.d via WAN 1") but that'd just be a bonus.
I've looked at a couple dual-WAN routers (the Duolinks SW24 and the Peplink Balance 20), and it's not clear whehter they'll do this. To be clear, I'm not looking for load balancing — I want to be able to control which network particular types of connections use.
I'm not opposed to building my own router if that's the only option; I probably remember enough iptables to make it happen. But I'd prefer to spend some cash if there's something that'll do this out of the box.
Best Answer
I've got this working now, here's what I did:
DD-WRT does work: I started with the guide that r.tanner.f linked (http://www.dd-wrt.com/wiki/index.php/Dual_WAN_with_failover) and was able to get things working (on a Asus WL-500w). However, it wasn't particularly great: I'm not good at iptables, and as I added more rules it seemed to actually slow the device down somewhat.
After more research I discovered that the Peplink Balance line does support policy-based routing (see http://www.peplink.com/technology/load-balancing-algorithms/), and I found a used Peplink Balance 20 on eBay for about $200 (they're normally $250-$300). I got it yesterday, it took less than an hour to set it up, and it's wonderful. Here's what the policy-based routing tool looks like:
There's ton more power there I'm not yet using including more complex routing (e.g. "prefer satellite, but fall back to DSL", "prefer DSL but if it's saturated fall over the satellite"), QoS, etc. Another cool feature is that I can tell the device my bandwidth caps for each connection and it'll track and notify me as I start to get close.
So yeah, suffice to say I'm a big fan. Well worth the investment for me.