1. ROCKWELL chipset slug team 2. serial port, asynchronization TTL 3. DC5V 4. Conform to the latest ITU V.90 and V.42 standard 5. Upload speed is 33.6Kbps,download speed is 56Kbps 6. Support dial under ligature 7. Support telephone call-on-hold 9. Four functions: Digital machine, answering machine,Fax machine, image machine