Protocol-independent support of remote DMA

摘要: A remote DMA (RDMA) shim protocol laid atop an existing network data transfer but logically underneath higher level disk and file access protocols specifies the portion of a packet to be transferred directly into separate area memory such as application layer buffer. This RDMA identifies which should delivered, ID, start, length or end, flag bits. Option fields added (or already present in) transport describe transfer. On reception specifying RDMA, receiving device delivers correct location using description data. In some embodiments invention, is implemented with TCP options specifically introduced enable thus reduce overhead transferring TCP-based NFS HTTP. Use option technique enables construction simple hardware accelerators copy from incoming buffers, avoiding expensive copies within stack. Alternatively, software techniques may used perform direct copying The stack decrease number required transfers, lowering costs.