Internet Congestion Control Research Group ICCRG


Internet congestion control crucially impacts network efficiency and user quality of experience (QoE). The Internet Congestion Control Research Group (ICCRG) is an IRTF group tasked with investigating innovative conceptual and practical aspects of Internet congestion control. The ICCRG brings together researchers and practitioners from academia and industry and strives to promote continued engagement by participants to facilitate an ongoing and lively discussion of congestion control research. Discussions in this group range from early, half-baked ideas that could benefit from feedback from the community to evaluations of widely-deployed congestion controllers and their impact on the Internet.

Topics of Interest:

The ICCRG’s primary focus is on the open Internet, broadly defined, though its interests extend to related network domains. In particular, topics of interest for the ICCRG include:

  1. Trends impacting Internet congestion control:
    • trends in application requirements: different types of emerging / existing application profiles, and the induced requirements from the network needed to support high QoE;
    • trends in traffic patterns: different types of emerging/existing traffic profiles and how to best support them;
    • interactions with the network: specific network characteristics (e.g., 5G, LTE, wired), QoS mechanisms, signaling mechanisms (e.g., ECN, INT), traffic engineering, lower-layer technologies;
    • interactions with other traffic: traffic controlled by different congestion controllers, DDoS and mitigation mechanisms, other forms of bandwidth consumption/protection.
  2. Novel approaches to Internet congestion control protocol design:
    • new design objectives, e.g., application-oriented/QoE-aware protocol design.
    • new algorithmic approaches, e.g., control-theoretic, learning-based
    • rethinking the design space, e.g., novel schemes for multipath congestion control.
  3. New evaluation frameworks for congestion control.
    • new formal models and performance metrics/criteria for congestion control, spanning different notions of performance, fairness, stability, etc.
    • network simulation/emulation frameworks for congestion control, including new experimentation tools and proposed experiments.
    • empirical datasets for evaluating congestion control protocols that reflect real-world challenges for Internet congestion control.
    To accommodate reproducibility, we strongly encourage participants to share code for congestion control prototypes and evaluation tools, as well as (possibly anonymized) useful datasets with the community.
  4. Evaluation of (existing and new) congestion controllers.
    • Theoretical results for Internet congestion control, e.g., theoretical guarantees for specific congestion controllers, general impossibility results, inherent tradeoffs between different objectives, etc.
    • Experimental/empirical evaluation results describing the behavior of different congestion controllers and contrasting different congestion control schemes. This includes comparative academic studies, as well as input from practitioners working on congestion control, even if limited to their own network environments or use cases.

    If you are working on something that you believe is in scope for ICCRG but are uncertain, please reach out to the chairs.

    “Soft” Deliverables:

    The ICCRG’s goal is to enhance our understanding of Internet congestion control and to support conceptual innovation. Hence, while ICCRG discussions might entail writing documents, these are not a required or expected outcome of the ICCRG. In particular, the ICCRG does not produce standards-track RFCs (although it can publish Experimental or Informational RFCs). The IETF is the appropriate venue for deployment-oriented documents concerning interoperability or standardization of implementation, where the ICCRG will coordinate with the IETF transport area as appropriate.

    While oral presentations of ideas at ICCRG meetings and any subsequent discussions are the primary form of communicating ideas at the ICCRG, participants are encouraged to deposit artifacts, such as datasets, draft research papers, documents covering recent theoretical/empirical results on Internet congestion control, for review, discussion, or collaboration. These artifacts are not intended as replacements to Internet drafts and may be provided in any appropriate format.


    The ICCRG will coordinate with other IRTF research groups, the IETF Transport Area, practitioners in industry, and the broader research community as appropriate.

    Membership Policy



    The ICCRG is chaired by Simone Ferlin, Reese Enghardt and Vidhi Goel.

    Mailing List

    The ICCRG mailing list is To subscribe or access the list archives, visit the mailman page.


    Documents and meeting materials for the ICCRG can be found on the IETF datatracker.

    Web Page

    Additional ICCRG information is available at


    The ICCRG was chartered on 2014-11-13.