Dirk Kutscher

How can we obtain the benefits of network-assisted multipath transport without changing Internet routing?

Our paper on "MARS: Multipath Adaptive Reliable Service has been accepted for publication at the 34th IEEE International Conference on Network Protocols (ICNP). It addresses this question by combining receiver-driven transport with lightweight overlay forwarders that safely discover additional forwarding opportunities and coordinate congestion control close to network bottlenecks.

Modern cloud services, geo-distributed AI systems, and large-scale content distribution increasingly depend on moving massive amounts of data across heterogeneous wide-area networks. Existing multipath transports, such as MPTCP and MPQUIC, can only exploit the paths visible to endpoints, while routing-based approaches require changes to network infrastructure.

At a glance, MARS augments traditional endpoint multipath with lightweight receiver-driven overlay forwarding.

MARS (Multipath Adaptive Reliable Service) explores a different direction. Rather than relying solely on endpoint scheduling or modifying Internet routing, MARS introduces lightweight, deployable forwarding assistance in an overlay network.

MARS combines receiver-driven transport with cooperating overlay forwarders that safely discover additional forwarding opportunities and react to congestion much closer to network bottlenecks—all while running as an incrementally deployable UDP overlay that requires no changes to Internet routers or routing protocols.

Key Ideas

• Safe overlay path discovery that expands usable path diversity while preventing forwarding loops, backward steering, and excessive path inflation.
• Receiver-driven congestion control coordinated with intermediate forwarders using lightweight queue feedback.
• Incremental deployment, allowing MARS to operate at endpoints alone while automatically benefiting from additional cooperating overlay forwarders.
• Robust operation under heterogeneous WAN conditions, packet loss, and transient network failures.

Results

We evaluate MARS through both large-scale ndnSIM simulations and a working Mininet prototype.

The results show that:

• MARS remains competitive even with endpoint-only deployment.
• Additional overlay forwarders expose significantly richer path diversity.
• MARS reduces worst-case 95th-percentile Flow Completion Time (FCT) by up to 81.5% compared with ECMP-limited multipath baselines.
• MARS remains robust under packet loss and quickly adapts to transient network failures.

Why It Matters

MARS demonstrates how Information-Centric Networking enables deployable receiver-driven overlay multipath without requiring changes to Internet routing. Rather than replacing today's Internet, MARS shows how lightweight receiver-driven forwarding can incrementally extend existing infrastructures with richer path diversity, faster congestion response, and improved robustness for modern WAN applications.

Reference

• Yitong Li, Xinjiao Li, Dirk Kutscher; MARS: Multipath Adaptive Reliable Service, to appear in the proceedings of the 34th IEEE International Conference on Network Protocols (ICNP); Tempe, Arizona, USA, October 05-08, 2026
• Pre-print on arxiv

Our paper on "MultiMoQ: Multi-Access Media-Over-QUIC for Robust Immersive Video Streaming" has been accepted for publication at ACM Multimedia 2026.

Abstract

Live immersive video streaming, particularly 360° video, is increasingly adopted in applications such as virtual events, sports broadcasting, and remote education. Existing approaches struggle to support high-bitrate immersive streaming for large numbers of concurrent users, with coarse-grained delivery limiting responsiveness and insufficient support for coordinating concurrent tile streams. Media over QUIC (MoQ) has recently emerged as a promising solution for large-scale media delivery, yet it lacks robustness under bandwidth-constrained conditions, often resulting in playback stalls.

To address these challenges, we present MultiMoQ, a multi-access tile streaming framework built on MoQ that redesigns its delivery mechanism to enable robust high-bitrate streaming across multiple access paths, while supporting flexible tile scheduling and seamless access switching without playback stalls.

We implement a fully functional prototype of MultiMoQ and evaluate it in network emulation under heterogeneous real-world network conditions, comparing against Dynamic Adaptive Streaming over HTTP (DASH) and standard MoQ. Results show that MultiMoQ significantly improves robustness, increasing average goodput by about 61% and reducing tail end-to-end latency by about 69% compared to DASH, while reducing average stall time by about 97%ccompared to standard MoQ. These transport gains also translatecinto smoother viewport playback, reducing playback freeze ratio to 1.09%, compared with 3.96% for standard MoQ and 51.5% for DASH.

Reference

• Yitong Li, Xinjiao Li, Ruonan Chai, Dirk Kutscher; MultiMoQ: Multi-Access Media-Over-QUIC for Robust Immersive Video Streaming; to appear in the proceedings of ACM Multimedia 2026; Rio de Janeiro, Brazil — 10–14 November 2026
• pre-print on arxiv

Our paper on COMETS: Coordinated Multi-Destination Video Transmission with In-Network Rate Adaptation has been accepted for publication by IEEE Transactions on Multimedia (TMM)

Abstract

Large-scale video streaming events attract millions of simultaneous viewers, stressing existing delivery infrastructures. Client-driven adaptation reacts slowly to shared congestion, while server-based coordination introduces scalability bottlenecks and single points of failure. We present COMETS, a coordinated multi-destination video transmission framework that leverages information-centric networking principles such as request aggregation and in-network state awareness to enable scalable, fair, and adaptive rate control. COMETS introduces a novel range-interest protocol and distributed in-network decision process that aligns video quality across receiver groups while minimizing redundant transmissions. To achieve this, we develop a lightweight distributed optimization framework that guides per-hop quality adaptation without centralized control. Extensive emulation shows that COMETS consistently improves bandwidth utilization, fairness, and user-perceived quality of experience over DASH, MoQ, and ICN baselines, particularly under high concurrency. The results highlight COMETS as a practical, deployable approach for next-generation scalable video delivery.

Introduction to COMETS

Nowadays, large streaming events typically attract millions of viewers, and the demand for concurrent video consumption is also expanding dramatically. For example, the number of monthly sports streaming viewers have grown from 57 million in 2021 to more than 90 million in 2025, with more than 17% users participating in multiple streams simultaneously. This explosive growth exposes fundamental limitations in existing video delivery architectures: how to maintain consistent, fair Quality of Experience (QoE) when thousands of users compete for shared bottleneck resources.

Existing infrastructures are not designed for effective coordination and resource sharing among large numbers of simultaneous viewers, resulting in inefficient management of concurrent requests for the same content segments and insufficient coordination of network resource allocation among users of the shared infrastructure. These inefficiencies lead to redundant data transmission and suboptimal bandwidth utilization, ultimately impairing user QoE by increasing network congestion, unstable bitrates, and higher incidences of buffering, especially during peak usage scenarios. To address these challenges, an ideal video delivery system must possess coordinated, scalable, and adaptive capabilities to maximize bandwidth utilization while ensuring a fair, high-quality experience for all users. Such a system should aggregate requests for the same content to eliminate redundancy, make intelligent in-network decisions and distribute computational load to avoid bottlenecks.

a) Latency vs. User Load	b) Mean Bitrate vs. User Load

Figure 1: Performance Comparison between baseline MoQ and server-optimized MoQ under increasing user load.

Current solutions exhibit fundamental limitations with respect to coordination and scalability. Client-adaptive approaches like Dynamic Adaptive Streaming over HTTP (DASH) enable individual clients to select video representations independently. However, their uncoordinated decisions, based on delayed and localized network views, lag behind the actual state of shared network bottlenecks, leading to bandwidth contention and bitrate oscillations. Server-side approaches address these limitations by centralizing adaptation logic, enabling optimal resource allocation through comprehensive network and user demand assessments. However, managing state and control interactions for numerous users introduces scalability challenges, and centralized decision architectures create single points of failure that compromise real-time performance. Our experiments (Figure 1) demonstrate that even state-of-the-art server-optimized Media over QUIC (MoQ) ultimately encounters the same scalability barriers as baseline approaches under high concurrency.

Key Insights

We observe that effective multi-user video streaming requires two properties: I). aggregation-aware delivery, where identical requests are merged to eliminate redundant transmissions, and II). distributed coordination, where adaptation decisions are made at points of request convergence rather than at centralized endpoints. This leads us to consider Information-Centric Networking (ICN). ICN provides inherent advantages for multi-user content distribution through in-network caching and request aggregation in systems like CCNx/NDN. While these features reduce redundant transmissions by merging duplicate requests at forwarders, existing ICN-based solutions focus on hop-by-hop adaptation rather than coordinated multi-user rate adaptation, suffering from decision lag and failing to ensure efficient convergence toward stable, fair rate allocations (i.e., equitable QoE distribution). To address these limitations, we present COMETS (Coordinated Multi-Destination Video Transmission with In-Network Rate Adaptation), a scalable, ICN-based multi-destination video streaming framework engineered to resolve challenges in large-scale video delivery: redundant data transmission, lack of scalable coordination, and inefficient system convergence.

Design Philosophy

COMETS is based on three principles that distinguish it from prior work: I). Group-aware rather than individual optimization. Instead of each client independently selecting bitrates, COMETS groups receivers with similar capabilities and network conditions, then aligns video quality across each group. This transforms the combinatorial complexity of individual decisions into tractable group-level optimization. II). Proactive rather than reactive adaptation. Unlike existing ICN approaches that react to congestion signals, COMETS uses a distributed Lagrangian framework where forwarders exchange dual variables (price signals) to anticipate upstream constraints. This enables proactive coordination without centralized state collection. III). Deployable overlay architecture. COMETS requires no modifications to network infrastructure. To ensure deployability, COMETS is architecturally flexible and can be deployed as an application-layer overlay network over existing Internet protocols (e.g., HTTP/QUIC over UDP), similar to Content Delivery Networks (CDNs) like Akamai or CloudFlare. It requires no infrastructure modifications and assumes trusted intermediate nodes under the same administrative domain, enabling immediate integration into today’s networks without network-layer changes. While COMETS shares MoQ’s vision of moving intelligence into the network, it avoids central bottlenecks by enabling per-hop optimization via ICN primitives, and is deployable over MoQ-capable infrastructures as an overlay.

Our Approach. COMETS transforms video streaming from isolated endpoint control into coordinated in-network negotiation, with four key contributions:

• Range-interest protocol for coordinated adaptation. We introduce a novel protocol where clients express resolution ranges rather than specific quality levels. This enables forwarders to aggregate requests and optimize resolution assignments across user groups, shifting adaptation logic from endpoints to the network fabric.
• Scalable architecture without central bottlenecks. COMETS distributes adaptation logic across forwarders, combining request aggregation with per-hop decision-making.
• Distributed optimization with closed-form solutions. We formalize coordinated multi-destination video transmission as a unified Integer Linear Programming (ILP) problem and develop a two-stage distributed algorithm. Unlike prior ICN approaches that rely on heuristics or reactive congestion signals, our method derives analytical closed-form solutions for per-hop quality decisions, enabling proactive, group-aware rate allocation with provable convergence guarantees.
• Implementation and Evaluation: Through extensive emulation on Mini-NDN with up to 300 concurrent clients, we demonstrate that COMETS achieves consistent QoE scores above 0.7 across all tested scales, while baselines degrade below 0.5 at high concurrency. COMETS maintains near-perfect fairness (Jain’s index ≥ 0.93) and achieves optimization convergence within 50ms—up to 3.7× faster than centralized approaches.

References

Yulong Zhang, Ying Cui, Zili Meng, Abhishek Kumar, Dirk Kutscher; COMETS: Coordinated Multi-Destination Video Transmission with In-Network Rate Adaptation; IEEE Transactions on Multimedia; 2026; pre-print: https://arxiv.org/abs/2601.18670

Our paper on INDS: Incremental Named Data Streaming for Real-Time Point Cloud Video has been accepted at ACM Multimedia 2025.

Abstract:

Real-time streaming of point cloud video – characterized by high data volumes and extreme sensitivity to packet loss – presents significant challenges under dynamic network conditions. Traditional connection-oriented protocols such as TCP/IP incur substantial retransmission overhead and head-of-line blocking under lossy conditions, while reactive adaptation approaches such as DASH lead to frequent quality fluctuations and a suboptimal user experience. In this paper, we introduce INDS (Incremental Named Data Streaming), a novel adaptive transmission framework that exploits the inherent layered encoding and hierarchical object structure of point cloud data to enable clients to selectively request enhancement layers based on available bandwidth and decoding capabilities. Built on Information-Centric Networking (ICN) principles, INDS employs a hierarchical naming scheme organized by time windows and Groups of Frames (GoF), which enhances cache reuse and facilitates efficient data sharing, ultimately reducing both network and server load. We implemented a fully functional prototype and evaluated it using emulated network scenarios. The experimental results demonstrate that INDS reduces end-to-end delay by up to 80%, boosts effective throughput by 15%–50% across diverse operating conditions, and increases cache hit rates by 20%–30% on average.

References

Ruonan Chai, Yixiang Zhu, Xinjiao Li, Jiawei Li, Zili Meng, Dirk Kutscher; INDS: Incremental Named Data Streaming for Real-Time Point Cloud Video; accepted for publication at ACM Multimedia 2025; October 2025

Our 2024 paper on Networked Metaverse Systems: Foundations, Gaps, Research Directions has been mentioned as one most popular and impactful papers of the IEEE Open Journal of the Communications Society (OJCOMS) 2024–2025.

References

• https://dirk-kutscher.info/publications/networked-metaverse-systems/
• Y. Zhang, D. Kutscher and Y. Cui, "Networked Metaverse Systems: Foundations, Gaps, Research Directions," in IEEE Open Journal of the Communications Society, vol. 5, pp. 5488-5539, 2024, doi: 10.1109/OJCOMS.2024.3426098.

The ICNRG Meeting at IETF-121 takes place on 2024-11-05, 13:00 to 14:30 UTC.

• Agenda and Presentations
• MeetEcho
• Notes
• IETF-121 Agenda

ICNRG Agenda

Please remember that all sessions are being recorded.

Material

1. https://datatracker.ietf.org/doc/draft-irtf-icnrg-flic/
2. https://datatracker.ietf.org/doc/draft-mosko-icnrg-ccnxchunking/
3. https://github.com/mmosko/ccnpy
4. https://datatracker.ietf.org/doc/draft-irtf-icnrg-reflexive-forwarding/
5. https://datatracker.ietf.org/doc/draft-hong-icn-metaverse-interoperability/
6. https://datatracker.ietf.org/doc/draft-li-icnrg-damc/

We updated our Internet Draft draft-irtf-icnrg-reflexive-forwarding-00 on Reflexive Forwarding for CCNx and NDN Protocols.

Current Information-Centric Networking protocols such as CCNx and NDN have a wide range of useful applications in content retrieval and other scenarios that depend only on a robust two-way exchange in the form of a request and response (represented by an Interest-Data exchange in the case of the two protocols noted above). A number of important applications however, require placing large amounts of data in the Interest message, and/or more than one two-way handshake. While these can be accomplished using independent Interest-Data exchanges by reversing the roles of consumer and producer, such approaches can be both clumsy for applications and problematic from a state management, congestion control, or security standpoint. This specification proposes a Reflexive Forwarding extension to the CCNx and NDN protocol architectures that eliminates the problems inherent in using independent Interest-Data exchanges for such applications. It updates RFC8569 and RFC8609.

The recent update includes a generalization of the main protocol specification, so that Reflexive Forwarding can be used in both CCNx and NDN.

On October 10th, 2024, I was invited to give a talk at the 2nd Airbus Workshop on Networking Systems. The workshop largely discussed connected aircraft scenarios and technologies and features talks on security and reliability, IoT sensor fusioning, and future space and 6G network architectures.

My talk was on Connected Aircraft – Network Architectures and Technologies, and discussed relevant scenarios from my perspective, such as passenger services and new aircraft management applications. For the technology discussion, I focused on large-scale low-latency multimedia communication over the expected heterogeneous and dynamic aircraft connectivity networks and discussed current and emerging technologies such as Media over QUIC, ICN.

I also introduced the recently established Low-Altitude Systems and Economy Research Institute at HKUST(GZ), a cross-disciplinary research institute for the low-altitude domain (with similar but not identical requirements) and some of our recent projects such as Named Data Microverse.

The term ‘Metaverse’ often denotes a wide range of existing and fictional applications. Nevertheless, there are actual systems today that can be studied and analyzed. However, whereas a considerable body of work has been published on applications and application ideas, there is less work on the technical implementation of such systems, especially from a networked systems perspective.

In a recently published open access journal article, we share some insights into the technical design of Metaverse systems, their key technologies, and their shortcomings, predominantly from a networked systems perspective. For the scope of this study, we define the ‘Metaverse’ as follows. The ‘Metaverse’ encompasses various current and emerging technologies, and the term is used to describe different applications, ranging from Augmented Reality (AR), Virtual Reality (VR),and Extended Reality (XR) to a new form of the Internet or Web. A key feature distinguishing the Metaverse from simple AR/VR is its inherently collaborative and shared nature, enabling interaction and collaboration among users in a virtual environment.

Building on Existing Platforms and Network Stacks

Most current Metaverse systems and designs are built on existing technologies and networks. For example, massively multiplayer online games such as Fortnite use a generalized client-server model. In this model, the server authoritatively manages the game state, while the client maintains a local subset of this state and can predict game flow by executing the same game code as the server on approximately the same data. Servers send information about the game world to clients by replicating relevant actors and their properties. Commercial social VR platforms such as Horizon Worlds and AltspaceVR use HTTPS to report client-side information and synchronize in-game clocks across users.

Mozilla Hubs, built with A-Frame (a web framework for building virtual reality experiences), uses WebRTC communication with a Selective Forwarding Unit (SFU). The SFU receives multiple audio and video data streams from its peers, then determines and forwards relevant data streams to connected peers. Blockchain or Non-Fungible Token (NFT)-based online games, such as Decentraland, run exclusively on the client side but allow for various data flow models, ranging from local effects and traditional client-server architectures to peer-to-peer (P2P) interactions based on state channels; Upland is built on EOSIO, an open-source blockchain protocol for scalable decentralized applications, and transports data through HTTPS. Connections between peers in Upland are established using TLS or VPN tunnels.

Many studies have focused on improving various aspects of Metaverse systems. For example, EdgeXAR is a mobile AR framework using edge offloading to enable lightweight tracking with six degrees of freedom (DOF) while reducing offloading delay from the user’s view; SORAS is an optimal resource allocation scheme for edgeenabled Metaverse, using stochastic integer programming to minimize the total network cost; Ibrahim et al. explores the issue of partial computation offloading for multiple subtasks in an in-network computing environment, aiming to minimize energy consumption and delay. However, these ideas for offloading computation and rendering tasks to edge platforms often conflict with the existing end-to-end transport protocols and overlay deployment models. Recently, a Deep Reinforcement Learning (DRL)-based multipath network orchestration framework designed for remote healthcare services is presented, automating subflow management to handle multipath networks. However, proposals for scalable multi-party communication would require interdomain multicast services, unavailable on today’s Internet.

Disconnect Between High-Level Concepts and Actual Systems

In practice, there is a significant disconnect between high-level Metaverse concepts, ideas for technical improvements, and systems that are actually developed and partially deployed. A 2022 ACM IMC paper titled Are we ready for metaverse?: a measurement study of social virtual reality platforms analyzes the performance of various social VR systems, pinpointing numerous issues related to performance, communication overhead, and scalability. These issues are primarily due to the fact that current systems leverage existing platforms, protocols, and system architectures, which cannot tap into any of the proposed architectural and technical enhancements, such as scalable multi-party communication, offloading computation, rendering tasks, etc.

Rather than merely layering ‘the Metaverse’ on top of legacy and not always ideal foundations, we consider Metaverse as a driver for future network and web applications and actively develop new designs to that end. In our article, we take a comprehensive systems approach and technically describe current Metaverse systems, focusing on their networking aspects. We document the requirements and challenges of Metaverse systems and propose a principled approach to system design for these requirements and challenges based on a thorough understanding of the needs of Metaverse systems, the current constraints and limitations, and the potential solutions of Internet technologies.

Article Overview

1. We present a technical description of the ‘Metaverse’ based on existing and emerging systems, including a discussion of its fundamental properties, applications, and architectural models.
2. We comprehensively study relevant enabling technologies for Metaverse systems, including HCI/XR technologies, networking, communications, media encoding, simulation, real-time rendering and AI. We also discuss current Metaverse system architectures and the integration of these technologies into actual applications.
3. We conduct a detailed requirements analysis for constructing Metaverse systems. We analyze applications specific requirements and identify existing gaps in four key aspects: communication performance, mobility, large-scale operation,and end system architecture. For each area, we propose candidate technologies to address these gaps.
4. We propose a research agenda for future Metaverse systems, based on our gap analysis and candidate technologies discussion. We re-assess the fundamental goals and requirements, without necessarily being constrained by existing system architectures and protocols. Based on a comprehensive understanding of what Metaverse systems need and what end-systems, devices, networks and communication services can theoretically provide, we propose specific design ideas and future research directions to realize Metaverse systems that can meet the expectations often articulated in the literature.

References

• Y. Zhang, D. Kutscher and Y. Cui; Networked Metaverse Systems: Foundations, Gaps, Research Directions; in IEEE Open Journal of the Communications Society, doi: 10.1109/OJCOMS.2024.3426098.
• Tianyuan Yu, Xinyu Ma, Varun Patil, Yekta Kocaogullar, Yulong Zhang, Jeff Burke, Dirk Kutscher, Lixia Zhang; Secure Web Objects: Building Blocks for Metaverse Interoperability and Decentralization; IEEE MetaCom 2024; August 12-14 2024; Hong Kong, China
• Dirk Kutscher, Jeff Burke, Giuseppe Fioccola, Paulo Mendes;
  Statement: The Metaverse as an Information-Centric Network; 10th ACM Conference on Information-Centric Networking (ACM ICN '23); October 9 — 10, 2023, Reykjavik, Iceland
• Giuseppe Fioccola , Paulo Mendes , Jeff Burke , Dirk Kutscher;
  Information-Centric Metaverse; Internet Draft draft-fmbk-icnrg-metaverse-01; Work in Progress; July 2023

In our upcoming paper at IEEE Metacom-2024, we propose a data-oriented approach for future Web and Metaverse system designs.

Abstract

This position paper explores how to support the Web's evolution through an underlying data-centric approach that better matches the data-orientedness of modern and emerging applications. We revisit the original vision of the Web as a hypermedia system that supports document composability and application interoperability via name-based data access. We propose the use of secure web objects (SWO), a data-oriented communication approach that can reduce complexity, centrality, and inefficiency, particularly for collaborative and local-first applications, such as the Metaverse and other collaborative applications. SWO are named, signed, application-defined objects that are secured independently of their containers or communications channels, an approach that leverages the results from over a decade-long data-centric networking research. This approach does not require intermediation by aggregators of identity, storage, and other services that are common today. We present a brief design overview, illustrated through prototypes for two editors of shared hypermedia documents: one for 3D and one for LaTeX. We also discuss our findings and suggest a roadmap for future research.

References

• Tianyuan Yu, Xinyu Ma, Varun Patil, Yekta Kocaogullar, Yulong Zhang, Jeff Burke, Dirk Kutscher, Lixia Zhang; Secure Web Objects: Building Blocks for Metaverse Interoperability and Decentralization; IEEE MetaCom 2024, pre-print: https://arxiv.org/abs/2407.15221

• Dirk Kutscher; Data-oriented, Decentralized, Daring: Opportunities and Research Challenges for an Information-Centric Web; Lightning Talk at NDNComm 2024; March 2024

• Navin V. Keizer, Onur Ascigil, Michał Król, Dirk Kutscher, and George Pavlou; A Survey on Content Retrieval on the Decentralised Web; ACM Computing Surveys; March 2024; https://doi.org/10.1145/3649132

• Dirk Kutscher, Jeff Burke, Giuseppe Fioccola, Paulo Mendes;
  Statement: The Metaverse as an Information-Centric Network; 10th ACM Conference on Information-Centric Networking (ACM ICN '23); October 9 — 10, 2023, Reykjavik, Iceland; https://doi.org/10.1145/3623565.3623761