RFC 9621 · PROPOSED STANDARD · 2025

Architecture and Requirements for Transport Services

Overview

RFC 9621, “Architecture and Requirements for Transport Services”, is a Proposed Standard document published in January 2025 by T. Pauly, B. Trammell, A. Brunstrom, G. Fairhurst, C. S. Perkins. The canonical text is published by the RFC Editor.

Abstract

This document describes an architecture that exposes transport protocol features to applications for network communication. The Transport Services Application Programming Interface (API) is based on an asynchronous, event-driven interaction pattern. This API uses Messages for representing data transfer to applications and describes how a Transport Services Implementation can use multiple IP addresses, multiple protocols, and multiple paths and can provide multiple application streams. This document provides the architecture and requirements. It defines common terminology and concepts to be used in definitions of a Transport Services API and a Transport Services Implementation.

Abstract as published in the RFC, via rfc-editor.org.

What “Proposed Standard” means

An entry-level standards-track specification: stable, peer-reviewed and a solid basis for implementation, though it may still evolve before becoming an Internet Standard.

Read this RFC

The canonical text of RFC 9621 is hosted at rfc-editor.org. Available in HTML,TXT,PDF,XML.

Other RFCs from 2025

Who Is Online

In total there are 59 users online: 0 registered, 51 guests and 8 bots.

Most users ever online was 5,555 on 17 Jul 2026, 3:23 am.

Bots: Applebot Baiduspider Bingbot Googlebot Other Bot Other Crawler PetalBot SemrushBot

Users active in the past 15 minutes. Total registered members: 372