You're on the right track by trying to configure per-line ringtone settings, but Webex Calling (Control Hub) currently does not fully support per-line ringtone or call alert suppression on the mobile app (iOS/Android) — only the desktop app respects those individual line ringtone settings.
Here's what’s happening:
Ringtone settings for shared lines (Line 2 & 3) in the desktop app can be configured to "Off" — and it works there.
However, on the Webex mobile app, these shared line settings are not honored consistently — all assigned lines may ring unless otherwise controlled centrally (from Control Hub or via workarounds).
Options to Prevent Shared Lines from Ringing on iOS:
Option 1: Remove Shared Line Appearance from Mobile App
This is the most effective method.
If the user doesn’t need to answer shared lines from mobile, you can:
Go to Control Hub > Users > [User] > Calling > Client Settings
Under Shared Line Appearance, unassign those shared lines from the mobile device profile or Webex app assignment.
Result: The shared lines will no longer appear or ring on the mobile app, but will remain active on the desktop app or MPP phone.
Option 2: Use "Silent" Custom Ringtone (iOS-side workaround)
Not ideal, but if the shared lines must appear on mobile:
