Sockets Direct Protocol

The Sockets Direct Protocol (SDP ) is an agreement (protocol) on the exchange of data between computers. This is a byte stream transport protocol, which mimics the Transmission Control Protocol (TCP).

SDP provides the application ( the user ) a single socket interface available. Due to this illustration, the standard socket operations on operations of the InfiniBand architecture socket based applications to take advantage of the benefits of InfiniBand Architecture ( IBA), without further adjustments. An SDP 's Upper Layer Protocol (ULP ) can now message-oriented over a Bytestromschnittstelle data with a reliable InfiniBand interconnect ( InfiniBand 's Reliable Connection) transmitted.

For the actual transfer, we distinguish between the following two methods:

• The buffer -copy mechanism uses to transfer data private buffer. For this purpose, it is necessary that the data is first copied from the memory in a private buffer and can then be transferred to another node.

• When zero -copy mechanism, however, the data between a DMA and a RDMA buffers with RDMA Read / Write transfer. It is therefore possible to memory areas of a remote node directly access without having to first create a copy of the memory area.

SDP has been specified by the InfiniBand Trade Association ( IBTA ).

• Network protocol