The CAM Database stores the (key, response) entries and performs matching by processing a Lookup Request. If the lookup key matches the key of any entry, there is a match and the response is output. The API software ensures that two entries using identical keys cannot be inserted. If the lookup key does not match the key of any entry, a no match indication is output together with a default response. The default response entry is a special entry without any key part. The key part is not necessary since this entry always matches if no other entry is matched.