HPN-SSH (High-Performance Networking SSH) is now the default implementation of SSH on Bridges2 DTNs (Data Transfer Nodes).
HPN-SSH maximizes network throughput for data transfers over long-haul network connections for protocols that employ SSH for authentication and encryption, such as SFTP and rsync. Clients do not need to make any updates to enjoy improved performance, however they may choose to take advantage of additional performance offered by the dedicated HPN-SSH client. More details can be found at the official HPN-SSH PSC docs site.