I may have confused myself here.
Tsm server 6.2.5, rhel 6.1, ibm 3494 library and ts1120 drives.

If I issue a

Udevadm info -attribute-walk

For all /dev/IBMtapexx devices I get a listing of everything that can be 
determined about these drives.

When defining these drives to tsm, which do I use for the "wwn" parm?
Do I use ww_node_name, or ww_port_name?

I think it would be  ww_port_name, but just checking before I add more drives.
On some of them, both are equal, but others the node_name and port_name differ.
Thanks for the assistance.