$1.$ Alice works for a small company that heavily relies on dial$-$up connections using modems for remote access. Additionally, the company has an internal TCP$/$IP network that connects various departments. As part of a system security review, Alice needs to assess and enhance the security of both the dial$-$up connections and the TCP$/$IP network. Please answer the following questions:

a$)$ Dial$-$Up Security :

$($i$)$ Identify and explain any TWO $(2)$ potential security risks associated with modem dial$-$up connections.

$($ii$)$ Based on your answer in $1($a$)($i$)$; propose TWO $(2)$ measures to enhance the security of dial$-$up connections.

$($iii$)$ Based on your answer in $1($a$)($ii$)$; provide a step$-$by$-$step implementation guide for both suggested security measures.