Replica seeding is a technique used to minimize the amount of data transferred over a slow or congested Wide Area Network (WAN) during the initial run of a replication job. It involves using a backup of the source virtual machine, physically transported to the disaster recovery (DR) site, as a baseline or "seed." The replication job then maps the replica to the existing VM data from the backup and transfers only the incremental changes that occurred since the backup was created. This drastically reduces the initial data volume sent across the WAN.

A. Deduplication is a standard data reduction technique used by Veeam, but it is not the specific primary benefit of the seeding process itself, which aims to avoid the initial full data transfer.
B. Compression is another standard Veeam feature for optimizing data transfer. It is applied to replication traffic regardless of whether seeding is used.
C. Encryption secures data in transit, which is a security feature. While important, it is not the primary performance-related benefit that seeding is designed to provide.

1. Veeam Backup & Replication V12 User Guide for VMware vSphere, "Replica Seeding" section: "To facilitate the replication process over a slow WAN link, you can perform replica seeding. Replica seeding helps you reduce the amount of traffic sent over the network during the first session of a replication job."

2. Veeam Backup & Replication V12 User Guide for VMware vSphere, "How Replica Seeding Works" section: "During the first session of the replication job, Veeam Backup & Replication does not read the whole VM image from the source side. It calculates digests for data blocks of the source VM and the 'seed' VM, compares them and transfers over the network only those data blocks that are new or changed."