Refer to the exhibit. IP phone A makes a call to IP phone B and RTP voice stream is successfully established between the endpoints. What option describes how to accomplish this call on phones with…

Setting common device configuration to IPv4 and IPv6 might allow devices to register with both, but does not solve the problem of media stream incompatibility when endpoints must use different IP versions for their media paths.

Setting the IP addressing mode preference for signaling affects how the phone registers and signals, but does not address the underlying media path incompatibility between two different IP versions.

When endpoints use different IP addressing versions (e.g., one is IPv4-only and the other is IPv6-only), a Media Termination Point (MTP) acts as a bridge. The MTP converts the media stream from one IP version to the other, allowing the RTP voice stream to be successfully established between the otherwise incompatible endpoints by assigning an MTP via a Media Resource Group.

While Cisco UCM supports alternative network address types, enabling them without the necessary MTP functionality for media stream translation will not resolve the incompatibility for the RTP stream itself.