It is expected that the RPC-over-RDMA transport will, at some point, allow protocol extensions to be defined. This would provide for the specification of OPTIONAL features allowing participants who implement the OPTIONAL features to cooperate as specified by that extension, while still interoperating with participants who do not support that extension. A particular extension is described herein, whose purpose is to reduce the latency due to inter-node round-trips needed to effect operations which involve direct data placement or which transfer RPC messages longer than the fixed inline buffer size limit.