The Data Restriction feature is assigned through the Class of Service feature. Data Restriction provides protection from disruption of any noise or tones on lines used primarily for data transmission, including modems and fax machines.

1. Prohibits distinctive ringing and provides one long ring. This is done to ensure that an answering machine or data device can see the ring.
2. Operates for all calls -- both within and outside of the switch.
3. Prevents any type of barge-in tone such as Call Waiting.