What is a location where the embedded multimedia terminal is connected to both outside and inside wiring

The answer to this question is "The main closet or telecommunications closet".

Explanation:

A multimedia terminal or multimedia terminal adapter (MTA) is also known as a Landline modem that operates just like a wireless router, but in terms of high-speed Internet, an MTA can provide Home Phone service only.

In the case of a significant power failure, MTAs have only a backup battery that will fuel the MTA for many hours. This device is used to connect to a main or telecommunications closet.