Look like the DM is trying to create a connection back to the NWS:

2013-01-14 16:57:01: NDMP: 7: Session 073 (thread ndmp073) < sent CONFIG_GET_EXT_LIST reply >

2013-01-14 16:57:01: NDMP: 7: Session 073 (thread ndmp073) < receive DATA_CONNECT request >

2013-01-14 16:57:01: NDMP: 7: Session 073 (thread ndmp073) < ip=0xa071020, port=0x23bc >

2013-01-14 16:57:01: NDMP: 10: connect: check concurrent data streams.

2013-01-14 16:57:01: NDMP: 6: Active NDMP backup/restore streams: 1, system configured concurrent streams: 4, maximum concurrent sessions supported: 4.

2013-01-14 16:57:01: NDMP: 7: Session 073 (thread ndmp073) NdmpdMover::getBuffer() success, buf 0x00582fc000, CALLER_ADDRESS 0x000154b253, CALLERCALLER_ADDRESS 0x0001541a3b

2013-01-14 16:58:16: NDMP: 7: Session 073 (thread ndmp073) < sent DATA_CONNECT reply, error: NDMP_CONNECT_ERR >

But no connection created, customer checking FW on his NWS.

VNX supports a maximum of eight NDMP sessions for each NDMP-Host Data Mover. By

default, up to four NDMP sessions are performed at a time. You can configure the Data

Mover to change the value of the NDMP sessions from four up to eight.

Two way to fix this issue

1. Distrubute your backup in such way not to run 4 backup jobs at a time.

2. Increase NDMP max session limit.

To change the value of concurrent sessions, use this command syntax:
$ server_param {ALL| } –facility NDMP –modify concurrentDataStreams
–value
where:
= name of the Data Mover
= number of concurrent NDMP sessions to be performed
Example:
To change the value of the concurrent NDMP sessions to eight, type:
$ server_param server_2 –facility NDMP –modify concurrentDataStreams –value 8
Note: If the Data Mover has less than 8 GB memory, you cannot set the value of the concurrentDataStreams parameter
to more than four. The server_param command will fail with the error message, "8 is not in range (1, 4)".

server_2: You must reboot server_2 for concurrentDataStreams changes to
take effect.