QUIC Working Group D. Liu Internet-Draft X. Yu Intended status: Informational Alibaba Group Expires: April 28, 2022 October 25, 2021 Multipath-QUIC Use Cases draft-liu-quic-mpquic-usecase-00 Abstract This draft introduces the use cases of multipath QUIC. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [1]. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on April 28, 2022. Copyright Notice Copyright (c) 2021 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of Liu & Yu Expires April 28, 2022 [Page 1] Internet-Draft Abbreviated-Title October 2021 the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Use Case 1: Redundant Transmission . . . . . . . . . . . . . 2 3. Use Case 2: bandwidth Aggregation . . . . . . . . . . . . . . 2 4. Use Case 3: Use Cases in 5G Core Network . . . . . . . . . . 2 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 3 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3 7. Security Considerations . . . . . . . . . . . . . . . . . . . 4 8. Normative References . . . . . . . . . . . . . . . . . . . . 4 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction This draft introduces multipath QUIC use cases. 2. Use Case 1: Redundant Transmission For applications such as Internet live video broadcasting, the user experience is very sensitive to delay. Especially for outdoor Internet live video broadcasting, the broadcasting device may equip two more cellphone cards to enable stable and robust network connection. In this case, multipath QUIC can provide redundant transmission over multiple network connections to improve user experience. For example, when some broadcasting packets were lost in one network connection, the redundant packets can be transmitted immediately by another connection without waiting for the timeout of the acknowledgements packets. 3. Use Case 2: bandwidth Aggregation For applications such as file download etc., if the device has multiple network access, for example, most smart phone today have both Wi-Fi and cellular network access, multipath QUIC can be used for bandwidth aggregation to accelerate the download speed. 4. Use Case 3: Use Cases in 5G Core Network Use case 3.1: 5GS is required to extend the bandwidth for the applications, such as high resolution video streaming. To achieve this purpose, the application is enabled to be access via different RAN, for example, different wireless access from PLMNs. Since 5GS can only support multipath for TCP and can not support multipath Liu & Yu Expires April 28, 2022 [Page 2] Internet-Draft Abbreviated-Title October 2021 functionality for non-TCP traffic, there is an urgent need for the multipath transport protocol for non-TCP traffic. The traffic splitting functionality in 5GS can be further enhanced by adopting QUIC with multipath extension, ensuring the bandwidth requirement for applications, such as high resolution video streaming. The NF (e.g. UPF) within 5GC may take charge of the QUIC multipath extension proxy functionality, which communicate with the multipath functionality in the client by using the QUIC multipath extension protocol. The ongoing discussion on 3GPP SA2 ATSSS R18 study item covers the research item and related requirement for the continue study of traffic splitting by considering the QUIC with multipath extension. The link for the draft of the study item is: https://www.3gpp.org/ftp/tsg_sa/WG2_Arch/TSGS2_147E_Electronic_2021- 10/Docs/S2-2107635.zip Use case 3.2: 5GS is required to ensure the reliability and QoE for applications, such as live video streaming, video on demand, etc. To achieve this purpose, the application is enabled to be accessed via different wireless paths, for example, 5G and Wi-Fi. However, due to the varied wireless environment, the packet sent by one path might be lost because of the poor signal and/or wireless interference. In this case, redundant transmission based on multipath is needed for guaranteeing reliability and QoE once the performance of the original path is deteriorated. The alternative path(s) may be able to send duplicated packets to the client in order to ensure the QoE. The NF (e.g. UPF) within 5GC may take charge of the QUIC multipath extension proxy functionality, which communicate with the multipath functionality in the client by using the QUIC multipath extension protocol. 3GPP SA2 has an ongoing discussion on ATSSS R18 study item. The redundant steering functionality has been written in the latest draft, which reflects the requirement on the redundant transmission. The link for the draft is: https://www.3gpp.org/ftp/tsg_sa/WG2_Arch/ TSGS2_147E_Electronic_2021-10/Docs/S2-2107635.zip 5. Acknowledgements 6. IANA Considerations This memo includes no request to IANA. Liu & Yu Expires April 28, 2022 [Page 3] Internet-Draft Abbreviated-Title October 2021 7. Security Considerations None 8. Normative References [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", March 1997, . [2] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629, DOI 10.17487/RFC2629, June 1999, . Authors' Addresses Dapeng(Max) Liu Alibaba Group Email: max.ldp@alibaba-inc.com Xiaobo Yu Alibaba Group Email: shibo.yxb@alibaba-inc.com Liu & Yu Expires April 28, 2022 [Page 4]