Transport and Services Working Group (tsvwg) Internet Drafts

      
 Transport Options for UDP
 
 draft-ietf-tsvwg-udp-options-45.txt
 Date: 16/03/2025
 Authors: Joseph Touch, C. Heard
 Working Group: Transport and Services Working Group (tsvwg)
 Transport protocols are extended through the use of transport header options. This document updates RFC 768 (UDP) by indicating the location, syntax, and semantics for UDP transport layer options within the surplus area after the end of the UDP user data but before the end of the IP datagram.
 A Non-Queue-Building Per-Hop Behavior (NQB PHB) for Differentiated Services
 
 draft-ietf-tsvwg-nqb-27.txt
 Date: 08/11/2024
 Authors: Greg White, Thomas Fossati, Ruediger Geib
 Working Group: Transport and Services Working Group (tsvwg)
 This document specifies characteristics of a Non-Queue-Building Per- Hop Behavior (NQB PHB). The NQB PHB provides a shallow-buffered, best-effort service as a complement to a Default deep-buffered best- effort service for Internet services. The purpose of this NQB PHB is to provide a separate queue that enables smooth (i.e. non-bursty), low-data-rate, application-limited traffic microflows, which would ordinarily share a queue with bursty and capacity-seeking traffic, to avoid the latency, latency variation and loss caused by such traffic. This PHB is implemented without prioritization and can be implemented without rate policing, making it suitable for environments where the use of these features is restricted. The NQB PHB has been developed primarily for use by access network segments, where queuing delays and queuing loss caused by Queue-Building protocols are manifested, but its use is not limited to such segments. In particular, applications to cable broadband links, Wi-Fi links, and mobile network radio and core segments are discussed. This document recommends a specific Differentiated Services Code Point (DSCP) to identify Non-Queue-Building microflows, and updates the RFC8325 guidance on mapping Diffserv to IEEE 802.11 for this codepoint. [NOTE (to be removed by RFC-Editor): This document references an ISE submission draft (I-D.briscoe-docsis-q-protection) that is approved for publication as an RFC. This draft should be held for publication until the queue protection RFC can be referenced.]
 Operational Guidance on Coexistence with Classic ECN during L4S Deployment
 
 draft-ietf-tsvwg-l4sops-07.txt
 Date: 17/03/2025
 Authors: Greg White
 Working Group: Transport and Services Working Group (tsvwg)
 This document provides guidance in order to ensure successful deployment of Low Latency Low Loss Scalable throughput (L4S) in the Internet. Other L4S documents provide guidance for running an L4S experiment, but this document is focused solely on potential interactions between L4S flows and flows using the original ('Classic') ECN over a Classic ECN bottleneck. The document discusses the potential outcomes of these interactions, describes mechanisms to detect the presence of Classic ECN bottlenecks, and identifies opportunities to prevent and/or detect and resolve fairness problems in such networks. This guidance is aimed at operators of end-systems, operators of networks, and researchers.
 DCCP Extensions for Multipath Operation with Multiple Addresses
 
 draft-ietf-tsvwg-multipath-dccp-22.txt
 Date: 22/03/2025
 Authors: Markus Amend, Anna Brunstrom, Andreas Kassler, Veselin Rakocevic, Stephen Johnson
 Working Group: Transport and Services Working Group (tsvwg)
 Datagram Congestion Control Protocol (DCCP) communications, as defined in RFC 4340, are inherently restricted to a single path per connection, despite the availability of multiple network paths between peers. The ability to utilize multiple paths simultaneously for a DCCP session can enhance network resource utilization, improve throughput, and increase resilience to network failures, ultimately enhancing the user experience. Use cases for Multipath DCCP (MP-DCCP) include mobile devices (e.g., handsets, vehicles) and residential home gateways that maintain simultaneous connections to distinct network types, such as cellular and Wireless Local Area Networks (WLANs) or cellular and fixed access networks. Compared to existing multipath transport protocols, such as Multipath TCP (MPTCP), MP-DCCP is particularly suited for latency- sensitive applications with varying requirements for reliability and in-order delivery. This document specifies a set of protocol extensions to DCCP that enable multipath operations. These extensions maintain the same service model as DCCP while introducing mechanisms to establish and utilize multiple concurrent DCCP flows across different network paths.
 Datagram PLPMTUD for UDP Options
 
 draft-ietf-tsvwg-udp-options-dplpmtud-15.txt
 Date: 20/02/2025
 Authors: Gorry Fairhurst, Tom Jones
 Working Group: Transport and Services Working Group (tsvwg)
 This document specifies how a UDP Options sender implements Datagram Packetization Layer Path Maximum Transmission Unit Discovery (DPLPMTUD) as a robust method for Path Maximum Transmission Unit discovery. This method uses the UDP Options packetization layer. It allows an application to discover the largest size of datagram that can be sent across a network path. It also provides a way to allow the application to periodically verify the current maximum packet size supported by a path and to update this when required.
 User Ports for Experiments
 
 draft-ietf-tsvwg-usr-exp-08.txt
 Date: 15/03/2025
 Authors: Joseph Touch
 Working Group: Transport and Services Working Group (tsvwg)
 This document defines user ports for experiments using transport protocols. It describes the use of experiment identifiers to enable shared use of these user ports, as well as updating the use of system ports for experiments in the same manner.
 Convergence of Congestion Control from Retained State
 
 draft-ietf-tsvwg-careful-resume-16.txt
 Date: 01/04/2025
 Authors: Nicolas Kuhn, Emile Stephan, Gorry Fairhurst, Raffaello Secchi, Christian Huitema
 Working Group: Transport and Services Working Group (tsvwg)
 This document specifies a cautious method for IETF transports that enables fast startup of CC for a wide range of connections. It reuses a set of computed CC parameters that are based on previously observed path characteristics between the same pair of transport endpoints. These parameters are saved, allowing them to be later used to modify the CC behaviour of a subsequent connection. It describes assumptions and defines requirements for how a sender utilises these parameters to provide opportunities for a connection to more rapidly get up to speed and rapidly utilise available capacity. It discusses how use of Careful Resume impacts the capacity at a shared network bottleneck and the safe response that is needed after any indication that the new rate is inappropriate.
 Authenticated Chunks for the Stream Control Transmission Protocol (SCTP)
 
 draft-ietf-tsvwg-rfc4895-bis-04.txt
 Date: 21/10/2024
 Authors: Michael Tuexen, Randall Stewart, Peter Lei, Hannes Tschofenig
 Working Group: Transport and Services Working Group (tsvwg)
 This document describes a new chunk type, several parameters, and procedures for the Stream Control Transmission Protocol (SCTP). This new chunk type can be used to authenticate SCTP chunks by using shared keys between the sender and receiver. The new parameters are used to establish the shared keys. This document obsoletes RFC 4895.
 Configuring UDP Sockets for ECN for Common Platforms
 
 draft-ietf-tsvwg-udp-ecn-00.txt
 Date: 19/12/2024
 Authors: Martin Duke
 Working Group: Transport and Services Working Group (tsvwg)
 Explicit Congestion Notification (ECN) applies to all transport protocols in principle. However, it had limited deployment for UDP until QUIC became widely adopted. As a result, documentation of UDP socket APIs for ECN on various platforms is sparse. This document records the results of experimenting with these APIs in order to get ECN working on UDP for Chromium on Apple, Linux, and Windows platforms.

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Transport and Services Working Group (tsvwg)

WG Name Transport and Services Working Group
Acronym tsvwg
Area Web and Internet Transport (wit)
State Active
Charter charter-ietf-tsvwg-07 Approved
Status update Show Changed 2019-02-05
Document dependencies
Additional resources GitHub
Issue tracker
Wiki
Zulip Stream
Personnel Chairs Martin Duke, Zaheduzzaman Sarker
Area Director Gorry Fairhurst
Mailing list Address tsvwg@ietf.org
To subscribe https://www.ietf.org/mailman/listinfo/tsvwg
Archive https://mailarchive.ietf.org/arch/browse/tsvwg/
Chat Room address https://zulip.ietf.org/#narrow/stream/tsvwg

Charter for Working Group

The Transport and Services Working Group (TSVWG) is the forum for development and publication of RFCs dealing with transport-layer topics that are not in scope of an existing working group or do not justify the formation of a new working group.

A non-exhaustive list of transport topics includes mechanisms that deal with packetization and reassembly, ports, maximum transmission unit discovery, reordering, congestion control, loss detection and recovery, queue management, explicit congestion notification, multihoming, stream multiplexing, and quality of service (including DSCP and RSVP). Transport-layer protocols include TCP, QUIC, SCTP, UDP, and DCCP. TSVWG maintains these protocols and mechanisms in the absence of a specialized working group.

The TSVWG mailing list is an open discussion forum for such work items, when they arise. The working group meets if there are active proposals that require discussion. The working group milestones are updated as needed to reflect the current work items and their associated milestones, with the approval of the responsible AD.

The currently active TSVWG work items mostly fall under the following topics:

(A) Maintenance and extension of the Stream Control Transmission Protocol
(SCTP), User Datagram Protocol (UDP), and Datagram Congestion Control Protocol (DCCP), as these do not have dedicated working groups.

(B) Explicit Congestion Notification (ECN), as the working group improves existing directives for tunnelling and observes the recently launched experiment with Low Latency, Low Loss, and Scalable Throughput (L4S).

(C) Maintenance of IP Differentiated Services (DiffServ) mechanisms, which involves mostly advisory documents on the use of DiffServ in specific application scenarios. Other work items related to DiffServ require Area Director approval.

Work in TSVWG must satisfy four conditions:
(1) WG consensus on the suitability and projected quality of the proposed work item.
(2) A core group of WG participants with sufficient energy and expertise to advance the work item according to the proposed schedule.
(3) Commitment from the WG as a whole to provide sufficient and timely review of the proposed work item.
(4) Agreement by the AD, who, depending on the scope of the proposed work item, may decide that an IESG review of adoption is needed first.

Milestones

Date Milestone Associated documents
Apr 2026 Submit "Configuring UDP Sockets for ECN for Common Platforms" as an Informational RFC draft-ietf-tsvwg-udp-ecn
Apr 2025 Submit "Operational Guidance for Deployment of L4S in the Internet" as an Informational RFC draft-ietf-tsvwg-l4sops
Mar 2025 Submit "DTLS over SCTP" as a Proposed Standard RFC draft-ietf-tsvwg-dtls-over-sctp-bis
Mar 2025 Submit "Authenticated Chunks for the SCTP" as a Proposed Standard RFC draft-ietf-tsvwg-rfc4895-bis
Dec 2024 Submit "User Ports for Experiments " for publication as a Proposed Standard RFC. draft-ietf-tsvwg-usr-exp
Nov 2024 Submit "Careful convergence of congestion control from retained state" for publication as a Proposed Standard RFC. draft-ietf-tsvwg-careful-resume

Done milestones

Date Milestone Associated documents
Done Submit "Datagram PLPMTUD for UDP Options" for publication as a Proposed Standard RFC. draft-ietf-tsvwg-udp-options-dplpmtud
Done Submit "A Non-Queue-Building Per-Hop Behavior (NQB PHB) for Differentiated Services" as a Proposed Standard RFC draft-ietf-tsvwg-nqb
Done Submit " Transport Options for UDP" as a Proposed Standard RFC draft-ietf-tsvwg-udp-options
Done Submit " DCCP Extensions for Multipath Operation with Multiple Addresses" as a Proposed Standard RFC draft-ietf-tsvwg-multipath-dccp
Done Submit 'Guidelines for Adding Congestion Notification to Protocols that Encapsulate IP' as a BCP RFC rfc9599 (was draft-ietf-tsvwg-ecn-encap-guidelines)
Done Submit 'Propagating Explicit Congestion Notification Across IP Tunnel Headers Separated by a Shim' as a Proposed Standard RFC rfc9601 (was draft-ietf-tsvwg-rfc6040update-shim)