A Fully Portable TCP Implementation Using XFSMs.

XTRA (XFSM for TRAnsport) is a first step towards "code-once-port-everywhere" transport protocols. XTRA's platform-agnostic programming abstraction, based on an extended finite state machine formalization of a desired transport layer task, is amenable not only to SW engines, but can be directly executed in CPU-less custom HW, thus permits to harness FPGA-based NICs' offloading opportunities without any re-coding effort. We experimentally demonstrate that XTRA enables us to port a customized TCP implementation across three completely different environments (HW proof-of-concept on a NetFPGA board, User-space SW over Linux' Open Data Plane, and NS3 emulator).