Yes. We often mix long distance SIP trunks with local SIP trunks. By least-cost routing long distance calls over the long distance trunks, you save the maximum amount of money.
Note: With Broadvox, you must purchase three minimum of any flavor of SIP trunks. If you wanted to purchase their long distance (GoAnywhere) and local (GoLocal) products, you would need three minimum of each.
For more insights on this topic: