The Microsoft Dynamics CRM data dip connector searches Telephone1, Telephone2, and MobilePhone. By default, these fields map to Business Phone, Home Phone, and Mobile Phone. However, you can configure the fields to map to different values. See https://help.mypurecloud.com/articles/how-the-microsoft-dynamics-crm-data-dip-connector-works/
The Oracle Service Cloud data dip connector searches Phones. Oracle Service Cloud stores all phone numbers for a contact into a list that the connector searches. Because the list contains raw numbers, the format of phone numbers is irrelevant. See https://help.mypurecloud.com/articles/how-oracle-service-cloud-data-dip-connector-works-oracle-service-cloud/
The Salesforce data dip connector searches Phone Fields. See https://help.mypurecloud.com/articles/how-salesforce-data-dip-connector-works-salesforce/
The Zendesk data dip connector searches Phone. See https://help.mypurecloud.com/articles/how-zendesk-data-dip-connector-works-zendesk/