What is DD Boost ??
DD Boost is a software add-on to the Domain Hardware.It perform below actions:-

1. It distributes some of the steps in  dedup process to media server or storage node.  This reduces the LAN traffic and weirdly the CPU load on the media server and DD.
2. Backup aware replication – Using the OST* standard the DD can be sent commands from an OST compatible application to initiate the replication of backups.  This way the backup app is aware of all the copies of data even though the DD performed the replication process.
3. Link Aggregation and Failover – The ports on the DD can be put into a DD Boost group meaning that the DD Boost software client on the host will balance the network traffic between them.  This improves the performance of backups. 

*OST

The OST API is protocol independent, meaning the hardware providers can utilize OST over whatever protocols are best suited for their devices including Fibre Channel, TCP/IP or SCSI.

The OST API provides 4 key features but the hardware vendors are not required to support all of them but rather just select the ones most suited for their devices.

OpenStorage Features

Direct Copy to dedicated tape drives

Direct Copy to shared tape drives

Optimized Duplication

Optimized Synthetics

One manufacturer that has strongly embraced OST is Quantum with their latest DXI Series appliances supporting both Optimized Duplication and Direct Copy to Shared Tape Drives. Using these features Quantum is able to replicate between DXI appliances or backup directly from a DXI to a tape library all while keeping NetBackup aware and the catalog consistent.