Legitimate GR-1221 documents are typically sold by standards organizations like Ericsson/Telcordia or provided by manufacturers to their clients. To give you a better "review," could you tell me:
GR-1221 - Reliability Passive Optical Components - Telcordia Datei herunterladen GR1221.zip
Are you working with or telecommunications? What is the file size ? Legitimate GR-1221 documents are typically sold by standards