When traveling using your CDMA you will be paying an arm and leg for your carrier’s roaming service. So, here are your choices:
1. Get a CDMA Global phone that allows you to put in a SIM card, or
2. Get a GSM Single SIM phone for traveling.

In either case, RoamHero will help you manage your calls. It will send your unanswered calls from your Home number to your Active SIM card on the phone you are using when you travel. It beats roaming and carrying two phones!