A Protocol-Independent Transport Architecture

TL;DR

PITA is a novel, protocol-independent transport architecture enabling full data-path programmability and high performance, supporting diverse protocols like TCP and RoCE on the same hardware.

Contribution

It introduces a uniform abstraction-based data-path design that allows full programmability and supports multiple protocols without protocol-specific assumptions.

Findings

Supports TCP and RoCE on the same data path

Achieves line-rate performance at 250MHz on FPGA hardware

Maintains high performance with modest hardware overhead

Abstract

The network transport layer is increasingly implemented in the NIC hardware to meet the performance demands of modern workloads, but this has made it difficult to evolve or deploy new transport protocols. Existing approaches either fix protocol logic in the data-path or build protocol-specific assumptions into the architecture that limit the range of protocols that can be supported on a single hardware substrate. We present PITA, a protocol-independent transport architecture that enables full data-path programmability while sustaining line-rate performance. PITA eliminates protocol-specific assumptions by structuring the data-path around a uniform abstraction over events, state, and instructions, and rethinks core components, including scheduling, packet generation, and data reassembly, to operate on this abstraction. We evaluate PITA along key dimensions reflecting the goals of its protocol-agnostic datapath design. Specifically, we show that PITA supports diverse protocol semantics by showing it can implement TCP and \roce on the same data path and preserve their distinct end-to-end behavior. Through targeted microbenchmarks and synthesis on Alveo U250 cards, we show that PITA's redesigned components sustain high performance under demanding conditions, with modest hardware overhead and meeting timing at 250MHz.