The AVLinkPro CH-100

The AVLinkPro CH-100 is an example if such offering.

A Simple Residential Premise SIP Bridge Controller.

• Great for up to 8 devices.
• Integrates with smart home systems like Crestron Home
• Allows for door intercom communication for a wide variety of brands and applications
• A Micro Sized Solid State Bridge link device that provides the connectivity in a simple format.
• Supports functions such as paging and video intercom bridge.
• Includes an onboard 2 pole dry contact relay.

Many more models to chosse from.
Watch this space for more to come