You can use third party telephony providers in JAICP. There are multiple telephony providers in the market that you can use. This article provides a couple of examples and specific connection instructions.
Vonage is a provider of cloud solutions for business communications.
Learn more how to connect Vonage
Zadarma is a cloud PABX with quick configuration and a wide choice of virtual numbers.
Register an account in Zadarma and create a new SIP connection in JAICP. When configuring a SIP connection, use details from the Settings > SIP connection in Zadarma. Also disable the Call without a country code option in the Settings > My profile > Calls tab.
How to connect the Zadarma provider and create an outbound call campaign, you can find in the step-by-step guide Call campaign.