Configure On-Call Scheduling with Notify to always use a user's preferred communication channel.

If Force communication channel is specified in the Escalation settings for rosters, the preferred user device is used, either SMS,Voice or email.

For example, if the preferred device is SMS, and the on-call member does not have an SMS device defined, the user is not contacted even if the user has an email address. When forcing a communication channel on an escalation level does not succeed, no further communication attempts are made. The fact that the user could not be reached is logged.