It is highly likely that this refers to a specific internal hostname, a logging entry, a malicious payload, or a misconfigured service you encountered.
Port Numbers: Standard FTP uses Port 21, but SFTP typically uses Port 22.
Avoid unless you fully control both ends and are inside a hardened, isolated network. Even then, use SFTP or FTPS. If you see "cdn1discovery ftp" in your logs, assume it is either:
FTP transmits credentials and data in cleartext. If cdn1discovery ftp is used over the public internet, an attacker on the same network can: