I love SingnalWire because they are the team behind an amazing open-source telephony solution, FreeSWITCH. And If I want to use a trunk for my customers to call US numbers I usually use them. Although their panel is very simple and you can create a sip account in a second and assign a DID to it but if you want to register their trunk in VICIdial you need to do some extra steps. Their transport is TLS and VICIdial is not configured for TLS connection by default so you need to create a cert and enable TLS configuration in sip.conf first. Here I explained how to configure VICIdial to support TLS connection and also what are the SIP trunk parameters when you want to use SignalWire as your carrier in VICIdial.