Look at this Wikipedia definition:
NDMP, or Network Data Management Protocol, is a protocol invented by the NetApp and Legato companies, meant to transport data between network attached storage (NAS) devices and backup devices. This removes the need for transporting the data through the backup server itself, thus enhancing speed and removing load from the backup server.
Most contemporary commercial, multi-platform backup software, such as Bacula, Amanda, CA ARCserve, EMC NetWorker, EMC Avamar, Symantec NetBackup, Backup Exec (since v11d), CommVault Simpana, Virtos S.O.S Backup, IBM Tivoli Storage Manager, Hitachi Data Systems (HDS), Dell Software NetVault Backup,Syncsort DPX, Zmanda, HP Data Protector and others support this protocol.
Supported NDMP filers/devices/appliances are listed in NetBackup 7 Hardware Compatibility List (HCL): http://http://www.symantec.com/docs/TECH76495
Config details can be found in the manuals:
NetBackup for NDMP Administrator's Guide http://www.symantec.com/docs/DOC5164
NDMP Appliance Information: http://www.symantec.com/docs/TECH31885 (This manual has a separate chapter for each supported vendor appliance with device-specific config details and limitations.)
Your question about hardware migration should be asked in a separate forum discussion.
In short - Symantec NetBackup is not tied to hardware, but rather to OS.
You can migrate from Sun Solaris (on SPARC) to Linux (on HP). See:
Using catalog backup and recovery to transfer NetBackup catalogs between UNIX or Linux master servers as part of a hardware refresh
http://www.symantec.com/docs/TECH77448
Unix to Windows migration needs Consulting engagement. See:
How to migrate the NetBackup catalog information from one platform to another (UNIX to Windows or vice versa), rename a Master Server, cluster an existing Master Server, or merge multiple NetBackup domains.
http://www.symantec.com/docs/TECH31385
If you have more questions about migration, please start a new discussion.
