Internet-Draft Web Traffic Management Principles October 2026
Meunier & Kelly Expires 2 May 2027 [Page]
Workgroup:
Network Working Group
Internet-Draft:
draft-meunier-bcp-civil-00
Published:
Intended Status:
Informational
Expires:
Authors:
T. Meunier
Cloudflare
K. Kelly
Anthropic

Principles for Web Traffic Management by Intermediaries

Abstract

This document describes principles for web intermediaries that balance security needs with open web accessibility.

About This Document

This note is to be removed before publishing as an RFC.

The latest revision of this draft can be found at https://thibmeu.github.io/draft-bcp-civil/draft-meunier-bcp-civil.html. Status information for this document may be found at https://datatracker.ietf.org/doc/draft-meunier-bcp-civil/.

Source for this draft and an issue tracker can be found at https://github.com/thibmeu/draft-bcp-civil.

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 2 May 2027.

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Table of Contents

1. Introduction

Web intermediaries such as content delivery networks, security services, and edge platforms increasingly implement traffic management systems to protect against abuse. As these systems become more sophisticated, there is growing concern about their impact on legitimate users and the open nature of the web.

This document establishes principles for responsible traffic management that preserve web accessibility while maintaining necessary protections.

2. Conventions and Definitions

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.

The following terms are used throughout this document:

Active signal:

Client property asserted by the client or its operator, verifiable by the intermediary, and not assertable by an unrelated party

Passive signal:

Inferred/heuristic client property

Graduated response:

Configurable action spectrum

Intermediary:

As defined in Section 3.7 of [RFC9110], an HTTP intermediary is a proxy, gateway, or tunnel that acts on behalf of either the client or server. This document also covers traffic management services integrated into proxies or applications.

3. Principles

The following principles should be followed by web intermediaries to balance\ security requirements with web openness:

  1. Intermediaries must classify traffic by specific behaviors, not by client identity

  2. Intermediaries must offer options other than block or allow

  3. Intermediaries must favor open protocols for traffic management decisions

  4. Intermediaries must prefer active signals over passive signals

  5. Intermediaries must document where their services diverge from published standards.

3.1. Behavior-based classification

Intermediaries must classify traffic by specific behaviors, not by client identity.

Classifications based on inferred client types (such as "bot" or "automated") are unreliable as the distinction between human and automated web browsing continues to blur. Modern web applications routinely use automation, and browsers themselves perform automated requests for prefetching, security scanning, and other legitimate purposes. Human users can be represented by software, including automated clients (Section 2 of [RFC8890]). Representing a user implies neither unconditional access nor an override of site policy.

Behavior-based classification focuses on observable actions that may indicate abuse, such as excessive request rates, unusual access patterns, or failure to respect machine-readable signals such as caching directives [RFC9111] and, for crawlers, the Robots Exclusion Protocol [RFC9309]. This approach enables more precise enforcement while avoiding false positives based on client characteristics.

Policies applied to every client must be general, such as not causing adverse impact on the site. More specific expectations apply according to the purpose a client declares, such as [CBCP] for crawlers.

3.2. Graduated enforcement

Intermediaries must allow traffic unless restrictions are required by the policy of the operator they act for (client or server), or necessary to protect availability (Section 4). They must make the policies they apply and their effects clear to that operator, and offer options other than block or allow.

Binary blocking decisions create unnecessary friction for legitimate users while failing to address the spectrum of potentially unwanted behavior. Graduated responses allow intermediaries to apply appropriate restrictions based on confidence levels and threat severity. Intermediaries should narrowly target restrictions to the relevant behavior, minimizing effects on unrelated users sharing infrastructure, applying the scope and granularity considerations in Section 4.1.1 of [RFC7754] and Section 4.1.2 of [RFC7754].

Effective responses include rate limiting (HTTP 429 status code), requests to retry after temporary overload (HTTP 503 with Retry-After), content modification per site policy (for instance, a summary or lower-quality variant), and verification challenges. Rate limiting implementations SHOULD follow emerging standards such as [draft-ietf-httpapi-ratelimit-headers] for consistent client communication. These responses can be applied progressively based on behavior patterns rather than defaulting to complete blocking for ambiguous cases.

Challenges and content modification can prevent legitimate clients from processing a response. Where site policy otherwise permits access, intermediaries should offer a documented recovery or alternative access path that does not depend on human interaction or a particular browser's capabilities. Such a path does not guarantee access and remains subject to the availability protections in Section 4.

3.3. Protocol neutrality

Intermediaries must favor open protocols for traffic management decisions and communicate responses using standard HTTP semantics.

Traffic management decisions should be based on standardized mechanisms that any client can implement, rather than proprietary systems or curated lists. This allows legitimate automated clients to identify themselves appropriately and follow established conventions for access control.

When responding to blocked or restricted requests, intermediaries MUST use appropriate HTTP status codes: 403 Forbidden for policy violations and 503 Service Unavailable for temporary overload or maintenance, as defined in [RFC9110], and 429 Too Many Requests for rate limiting, as defined in [RFC6585]. Response headers SHOULD provide actionable information about restrictions and recovery paths. For 429 and 503 responses, intermediaries SHOULD include Retry-After (Section 10.2.3 of [RFC9110]) when they can estimate when the client should retry.

Open protocols enable website owners to express their preferences consistently across different intermediaries, rather than managing separate configurations for each vendor's proprietary system.

3.4. Active signals over passive fingerprints

Intermediaries must prefer active signals over passive signals.

Passive fingerprinting techniques identify users without their participation, and create false positives for users sharing IP addresses, using privacy tools, or connecting from networks with unusual characteristics. These techniques also degrade over time as clients change behavior or implement countermeasures.

Active signals provide assurance about the asserted property, because the client or its operator positively asserts a property that the intermediary can verify. Examples include HTTP Message Signatures [RFC9421] profiles such as [draft-ietf-webbotauth-httpsig-protocol], Privacy Pass tokens [RFC9577], published IP ranges as recommended by [CBCP], and forward-confirmed reverse DNS.

Note that what differs is not necessarily the data itself. An observed IP address is a passive signal, while the same address published by its operator is an active signal.

Authentication and privacy-preserving tokens can improve traffic management, but do not by themselves resolve how legitimate clients without recognized credentials or supported challenge capabilities are treated. Absence of an active signal does not itself establish abuse.

3.5. Implementation transparency

Intermediaries must document where their services diverge from published standards.

Intermediaries that develop or promote standards operate multiple services that may implement those standards differently. An intermediary that promotes a standard should disclose where its services do not follow it.

While documenting every deviation may not be practical, intermediaries should prioritize disclosure in areas where they have established published guidance.

Where safe and feasible, intermediaries should distinguish explicit site-policy denial from suspected abuse or temporary overload, and provide operators enough information to investigate unintended blocking. This need not disclose detection rules or sensitive signals.

4. Security Considerations

Authentication does not by itself establish authorization or harmless behavior. Authenticated clients remain subject to site access policy and behavior-based limits. The preference for active signals does not require clients to identify themselves to access public resources.

Client assertions can be spoofed. Intermediaries should verify active signals using the relevant mechanism, including the authenticity and integrity of published identity data, before using them in access decisions.

Protecting availability can require immediate blocking or dropping connections. Graduated enforcement does not require trying every response first (Section 7.2 of [RFC6585]). Intermediaries should also limit the resources spent on signal verification and challenges.

Active identifiers and passive fingerprints can enable tracking. Intermediaries should minimize the collection and retention of identifying data and prefer mechanisms that disclose only the property needed for a decision.

5. IANA Considerations

This document has no IANA actions.

6. References

6.1. Normative References

[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/rfc/rfc2119>.
[RFC6585]
Nottingham, M. and R. Fielding, "Additional HTTP Status Codes", RFC 6585, DOI 10.17487/RFC6585, , <https://www.rfc-editor.org/rfc/rfc6585>.
[RFC8174]
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <https://www.rfc-editor.org/rfc/rfc8174>.
[RFC9110]
Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke, Ed., "HTTP Semantics", STD 97, RFC 9110, DOI 10.17487/RFC9110, , <https://www.rfc-editor.org/rfc/rfc9110>.

6.2. Informative References

[CBCP]
Illyes, G., Kühlewind, M., and K. Aj, "Crawler best practices", Work in Progress, Internet-Draft, draft-illyes-webbotauth-cbcp-01, , <https://datatracker.ietf.org/doc/html/draft-illyes-webbotauth-cbcp-01>.
[draft-ietf-httpapi-ratelimit-headers]
Polli, R., Ruiz, A. M., and D. Miller, "RateLimit header fields for HTTP", Work in Progress, Internet-Draft, draft-ietf-httpapi-ratelimit-headers-11, , <https://datatracker.ietf.org/doc/html/draft-ietf-httpapi-ratelimit-headers-11>.
[draft-ietf-webbotauth-httpsig-protocol]
Meunier, T. and S. Major, "HTTP Message Signatures for automated traffic", Work in Progress, Internet-Draft, draft-ietf-webbotauth-httpsig-protocol-00, , <https://datatracker.ietf.org/doc/html/draft-ietf-webbotauth-httpsig-protocol-00>.
[RFC7754]
Barnes, R., Cooper, A., Kolkman, O., Thaler, D., and E. Nordmark, "Technical Considerations for Internet Service Blocking and Filtering", RFC 7754, DOI 10.17487/RFC7754, , <https://www.rfc-editor.org/rfc/rfc7754>.
[RFC8890]
Nottingham, M., "The Internet is for End Users", RFC 8890, DOI 10.17487/RFC8890, , <https://www.rfc-editor.org/rfc/rfc8890>.
[RFC9111]
Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke, Ed., "HTTP Caching", STD 98, RFC 9111, DOI 10.17487/RFC9111, , <https://www.rfc-editor.org/rfc/rfc9111>.
[RFC9309]
Koster, M., Illyes, G., Zeller, H., and L. Sassman, "Robots Exclusion Protocol", RFC 9309, DOI 10.17487/RFC9309, , <https://www.rfc-editor.org/rfc/rfc9309>.
[RFC9421]
Backman, A., Ed., Richer, J., Ed., and M. Sporny, "HTTP Message Signatures", RFC 9421, DOI 10.17487/RFC9421, , <https://www.rfc-editor.org/rfc/rfc9421>.
[RFC9577]
Pauly, T., Valdez, S., and C. A. Wood, "The Privacy Pass HTTP Authentication Scheme", RFC 9577, DOI 10.17487/RFC9577, , <https://www.rfc-editor.org/rfc/rfc9577>.

Acknowledgments

TODO acknowledge.

Authors' Addresses

Thibault Meunier
Cloudflare
Kevin Kelly
Anthropic