Siva,Is that the firmware the phones are running or the firmware they're trying to upgrade to?  You may be jumping too many versions at once.Brian

Mohammed,What firmware version are you running on your 9971s?Thanks,Brian

Ah okay.  So if you connect a PC to the 871, can you download files from your PC running TFTPd64 using a TFTP client?  Does a packet capture show any traffic at all from the phone to your PC running TFTP?

So the TFTPd64 is most likely the issue here.  How did you define the TFTP server option in TFTPd64?  As option 150 or 66?  Check out http://reboot.pro/topic/2048-tftpd32-with-cisco-phones-option-150/

What type of connection do you have to the paging system?  FXO card?  FXS card?