We're a webdev company that has outgrown its ADSL bandwidth. It's currently 4/1 Mbit/s and due to distance we can't simply get faster DSL, whether ADSL or SDSL. Stacking multiple DSL connections is prohibitively expensive, and so is laying fiber due to us moving to another location in a year or so.

After shopping around it seems that Ethernet-over-Copper is our best bet. They will use several copper pairs and provide a 2/2 Mbit/s connection with a provider-independent IP range.

Since we need more downstream bandwidth than 2 Mbit/s, we would like to complement this with our current ADSL connection, which is with another ISP. We have a fixed IP from them.

In effect there would be two WAN connections, Ethernet (layer 2) and ADSL (layer 3), that would need to be aggregated into a single pipe.

Is this possible?

Do we need to somehow define rules based on traffic type or QoS somehow, or perhaps auto-balance based on load or connection-cost?

What kind of hardware do we need? We're willing to buy some Cisco or Juniper device since we don't currently have anything useful.

Any tips will be helpful since this is new territory for us.

  • why is bonded ADSL so expensive? In the UK there are numerous ISPs that'll offer bonded ADSL for just the cost of X * DSL lines.
    – Alnitak
    Dec 14, 2009 at 14:13
  • presumably because he doesn't have spare additional phone lines so those actual wires would need running?
    – Chopper3
    Dec 14, 2009 at 15:49
  • We do have unused wires, but we'd need about 4 pairs of 1/1 Mbit for any decent total speed. Several ISP's quoted us a setup cost of €5000+. Most of it for the router. The rest for connecting the lines. The monthly fee was steep too. Not an attractive option for an SMB company. Dec 15, 2009 at 22:36

5 Answers 5


You almost certainly can't combine the two lines in the way you probably want, where a request goes out one pipe/ISP and comes back in the other. The issue is your current ISP would need to be able to route your new IP block and that is highly unlikely.

What will probably be a better solution is to break requests out into services on different pipes or segment traffic based on IP. So you may send all web traffic to one pipe and all ftp traffic to another. That is actually not too hard to do with a CISCO router or any number of open source firewalls like Shorewall.

  • I see. Segmenting services will suit us fine. Is there no problem with the fact that one link is ADSL and the other is ethernet, due to different layers? Dec 14, 2009 at 15:00
  • I believe you will be fine because whatever does the traffic shaping will do it at the same layer for both paths.
    – carson
    Dec 14, 2009 at 18:30

Take a look at devices from: XRoads Network; mushroomnetworks or peplink




Why not use a small load balancer. Some of thse devices are avaialbe for as low as $2000.


Check out Elfiq - they are smoking hot, never had a problem with mine if fact it saved my skin a few times!


If you're talking about 50mbit or less combined (which I see you are), you may find something like a Cisco Linksys RV042, or a Peplink Balance or Cradlepoint MBR unit, quite satisfactory. As long as your connectivity comes in over Ethernet (whether it's bridged from ADSL or just plain old metro Ethernet), you should be fine.

One problem with this environment is that you may not be able to control which path a given stream (for lack of a more accurate term) goes out, and some (authenticated) websites get confused if you connect to them from two different IP addresses in the same session (Vonage and my work webmail tend to suffer from this).

A second issue is that your inbound connectivity isn't balanced. If you're mostly receiving traffic as a client (i.e. web browsing, downloading stuff) you should be fine, but if you were wanting high upload speeds to a webserver behind this gear, you'd be out of luck.

An upside to some of these options (not the RV042, but the other two) is that you can also get failover or balanced USB (or Expresscard) broadband to supplement your Ethernet connections.

Another upside is that a small number of these solutions support BGP, to make the best use of your "provider-independent IP range" if both providers support it.

I do this sort of balancing at home with ADSL2+ and a Cablemodem line (but without BGP); have used Cradlepoint's sub-$300 systems and currently have the RV042v1 (sub-$100 used) equipment.

I blogged about this at http://rsts11.wordpress.com/2013/03/18/how-many-internets-do-you-need-rsts11/ and am going to be looking at a couple of other solutions in the near future if I can pull together some free time.

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