HP 3PAR Operating System Software - Manual (Page 28)

◦ The node set up in synchronous mode must use Fibre Channel (RCFC), and the node set
up in asynchronous periodic mode must use IP links (RCIP).
◦ RCFC over an IP network is not supported for two-node Synchronous Long Distance
configurations.
For more information, see “Setting the Transport Layer” (page 33) .
28 Considering Requirements and Restrictions