PPP Connection established finally , it was a mismatch of Baud Rate between terminal PC  and the SP  . Manually change Baud Rate on SP side fix the issue. ( PC Baud Rate changing to 19200 always after set to 115200) 
i unable to reset password for my vnx 5300. i tried PP connection but no success. can anybody help me regarding this  
how to reset factory default VNX 5300