As the Round-Trip Time (RTT) between network grows, the amount of data that can flow across a TCP stream goes down. TCP gets hung up waiting for the acknowledgment (ACK) packets and the transfer rate goes down. One way to handle this is to make use of parallel connections that yield faster throughput for each RLINK. This way rather than waiting for the acknowledgments from a single stream you can have multiple ACKs going across.

Replicating through multiple TCP connection for each RLINK enables the maximum utilization of high latency and high-bandwidth networks. Single TCP connection usually fails to use the entire bandwidth. To enable optimum use of bandwidth available for each RLINK, Volume Replicator establishes multiple TCP connections to the Secondary. Multiple connections improve the overall replicating performance of Volume Replicator.