Balanced Sip Dial

I have two trunks that the freepbx needs to target.
I have custom extension that dial sip/[email protected]
I need to have a dial string that will alternate between the two trunks instead of just hitting the one. Do i accomplish with a context or how?

If you create custom trunks with the above dial string instead of custom extensions, you can then use the 3rd party module, Trunk Balancing: