The Real-time Transport Protocol (RTP) Media Portal is an optional
component that addresses media plane specific issues with advanced
service delivery, Internet addressing efficiencies, and system security.

The primary function of the RTP Media Portal is to extend the reach of
multimedia services so that they are accessible to obscured endpoints,
devices residing behind a firewall, or a Network Address Translation
(NAT) and/or Network Address Port Translation (NAPT) device.
Functioning as a media NAPT point that shields Multimedia
Communications Platform (MCP) Service Network components from
external exposure, the RTP Media Portal also provides IP address/port
pair mapping between internal and external network components as
well as media anchoring and media pivot abilities for terminals.

The RTP Media Portal may be deployed in a single- or dual-network
configuration. For dual-networks, the RTP Media Portal enables
elements in the Protected MCS Network to safely communicate with
elements in the Managed IP access network.