Every company may have the need to communicate over a WAN environment. A company may need to send data across a WAN between their data centre (at one location) and their remote offices (at other locations). A WAN enables data transfers to happen across geographies with a tradeoff of various network interruptions. These interruptions include (but are not limited to) intermittent disconnections, latency or chit chat, packet losses, and delays.
Prior to NetBackup 7.5 release, any disconnection in network over WAN environment will cause backups to fail
There are multiple solutions available to overcome these problems. There are other third party tools available which can help an application in recovering from such interruptions but, would involve software costs and/or hardware costs. Other solutions might also involve making the application itself resilient to such interruptions. NetBackup 7.5 includes a feature, Resilient Network, which will help data transfers over a WAN environment by becoming resilient to WAN interruptions.
Refer attached document for more details.