Correct Answer: The caller's calling search space must include a partition containing a route pattern that matches the dialed digits and points to a route list/route group associated with a properly configured, reachable voice gateway
Explanation: The CSS, an accessible partition, a matching route pattern, and a route list/group pointing to a reachable gateway must all align for successful PSTN routing, unlike unrelated factors such as wallpaper, ringtone, display brightness, handset color, or desk placement.
Correct Answer: The caller's calling search space must include a partition containing a route pattern that matches the dialed digits and points to a route list/route group associated with a properly configured, reachable voice gateway
Explanation: The CSS, an accessible partition, a matching route pattern, and a route list/group pointing to a reachable gateway must all align for successful PSTN routing, unlike unrelated factors such as wallpaper, ringtone, display brightness, handset color, or desk placement.