How to search (web API) for a Calls record by phone number?

How to search (web API) for a Calls record by phone number?

Using v8 /Calls/search web api I'm unable to to complete a search request no matter how I use the api:

When I try using "criteria=" I get:
  2. response: <Response [400]>
  3. response_json: {
  4.   "code": "INVALID_QUERY",
  5.   "details": {
  6.     "reason": "the field is not available for search",
  7.     "api_name": "To_Number__s"
  8.   },
  9.   "message": "Invalid query formed",
  10.   "status": "error"
  11. }


When I try using "phone=" I get:
  1. response: {
  2.   "code": "FIELD_TYPE_UNAVAILABLE",
  3.   "details": {},
  4.   "message": "this data type is not found in this module",
  5.   "status": "error"
  6. }

So, given a phone number, what web api will let me find Calls records related to that phone number?  (I don't have any associated Contact.  I have just the phone number)

Thanks
Clark