Using DSL + WiMax Together

A few months ago, I signed up for Clear WiMax. I decided to keep my Bellsouth ADSL connection as I have received notices from Clear that my ‘unlimited’ connection was being over-utilized.

I tried to combine both ADSL and WiMax connections by putting a switch on the WAN port of my router and assigning static IPs to the two connections. By using route tables inside the router I was able to direct high-usage traffic over one connection and route all other traffic over the other. This works good- except that when I put both connections to static IPs, I create double-NATs and I run into issues when trying to open ports to internal systems:


Furthermore, after trying a few different Open-WRT firmware versions (Tomato, Gargoyle, DD-WRT) I found that routing inside my WRT54GL to not always work as I wanted it to.

After several failed attempts, I came up with another idea: I disabled DHCP on the WiMax modem, gave it a static IP on my local network and plugged it into the LAN side of my router:


I then added outbound static routes on my PC to all direct traffic for GigaNews and BackBlaze to the WiMax modem:

route add –p mask
route add –p mask
route add –p mask
route add –p mask

These routes direct all outbound traffic for my blackblaze client (, and and GigaNews ( over the WiMax connection. All other traffic is passed to the default gateway and out to BellSouth.

I am using NetLimiter to monitor my bandwidth usage and restricting GigaNews downloads to about 6Mbps in NewsLeecher (I can still remove the cap and jump up to about 9Mbps if I an in a hurry for a specific article)- which appears to have stopped the ‘excessive usage’ emails/calls from Clear support.

On other hosts on my network I can leave Bellsouth as default or add the above routes if I want to connect in a similar manner.

I was also having some strange issues with the Gargoyle firmware was not automatically connecting via PPPoE, but the latest firmware and setting my MTU to 1500 appears to have resolved this.

On another note: the WiMax connection does not appear to be an asymmetrical connection; on my Bellsouth ADSL line, my download bandwidth decreases as my upload bandwidth is utilized- this is not the case with WiMax.

Now I am able to access a cumulative 12Mbps down/1Mbps up on my PC. In theory, I could break out the WiMax mobile and connect it to a 3G router and have a 3rd route- but I am not going to push my luck too much with Clear… :)


  1. This last write up you did on CLEAR is very impressive. Good information....and a killer graphic also.

    I've also been tinkering around with routers, directing traffic, and messing around with ports lately.

    My CLEAR desktop modem has worked with three different routers with no troubles at all.

    Thanks for the useful information. I'm in the process of throwing up some more pages about CLEAR and your posts will be center stage.

    My latest mention of CLEAR WiMAX Internet along with that funny commercial from CLEAR.

  2. nukemdomis: I may have been a bit unclear on my router issues with Clear.

    All of the routers I tried worked with Clear as the single external gateway.

    The issues I ran into were where the routers had issues routing to multiple WAN gateways- and mostly with mostly with versions of Open-WRT. The other issue I had was passing external port connections to internal devices via a double-NAT.

    The Clear modem is limited but very functional. I could find no faults with the modem and setting it up for a home network. :)