RMAN backup failing with "listen for client timeout error" with error code 83.

In the media server bp.conf we have already set below parameters but still no use.

CLIENT_READ_TIMEOUT = 3000
CLIENT_CONNECT_TIMEOUT = 600

Please find the error log failing with error code 83.

Nov 5, 2012 6:56:54 PM - Error bptm (pid=9568494) No passthru access to this drive
Nov 5, 2012 6:56:52 PM - requesting resource nbu-media1-nb-hcart3-robot-tld-2
Nov 5, 2012 6:56:52 PM - requesting resource sunsdd-nb.NBU_CLIENT.MAXJOBS.client1-nb
Nov 5, 2012 6:56:52 PM - requesting resource sunsdd-nb.NBU_POLICY.MAXJOBS.Ora_RMAN_KRP2
Nov 5, 2012 6:56:52 PM - granted resource  sunsdd-nb.NBU_CLIENT.MAXJOBS.client1-nb
Nov 5, 2012 6:56:52 PM - granted resource  sunsdd-nb.NBU_POLICY.MAXJOBS.Ora_RMAN_KRP2
Nov 5, 2012 6:56:52 PM - granted resource  H01713
Nov 5, 2012 6:56:52 PM - granted resource  TOL_T10000_08
Nov 5, 2012 6:56:52 PM - granted resource  nbu-media1-nb-hcart3-robot-tld-2
Nov 5, 2012 6:56:52 PM - estimated 0 kbytes needed
Nov 5, 2012 6:56:52 PM - started process bpbrm (pid=12582934)
Nov 5, 2012 6:56:54 PM - end writing
Nov 5, 2012 6:58:00 PM - Error bpbrm (pid=15007828) listen for client timeout during accept from data listen socket after 60 seconds
media open error  (83)

Please help me in resolving this issue.