CUCCX is a great platform but it can't be considered when working with other manufacturers, even if they support SIP. For this reason, when you're building a network that isn't just installed by one provider, I would suggest an approach different from CUCCX (considering VoIP …
Collab OneContact is an all around platform that can be used in any situation. It can be used in situation where there isn't a PBX. I've seen some solutions where the platform is integrated, using SIP with a CUCM.
CUCCX is a great platform but it can't be considered when working with other manufacturers, even if they support SIP. For this reason, when you're building a network that isn't just installed by one provider, I would suggest an approach different from CUCCX (considering VoIP and CC platforms, not routing or switching). OneContact allows the integration between platforms, allowing short number dialing between different contexts, recording other advanced telephony solution. Collab's Customer interaction Hub is a great solution for clients that need a CRM, but don't need much complexity, this mini-CRM is a great asset against the competition and facilitates the deployment of an omni-channel Contact Center.