Internet Engineering Task Force (IETF) Y. Sheffer Request for Comments: 7942 Intuit BCP: 205 A. Farrel Obsoletes: 6982 Juniper Networks Category: Best Current Practice July 2016 ISSN: 2070-1721
Improving Awareness of Running Code: The Implementation Status Section
This document describes a simple process that allows authors of Internet-Drafts to record the status of known implementations by including an Implementation Status section. This will allow reviewers and working groups to assign due consideration to documents that have the benefit of running code, which may serve as evidence of valuable experimentation and feedback that have made the implemented protocols more mature.
This process is not mandatory. Authors of Internet-Drafts are encouraged to consider using the process for their documents, and working groups are invited to think about applying the process to all of their protocol specifications. This document obsoletes RFC 6982, advancing it to a Best Current Practice.
Status of This Memo
This memo documents an Internet Best Current Practice.
This document is a product of the Internet Engineering Task Force (IETF). It has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on BCPs is available in Section 2 of RFC 7841.
Copyright (c) 2016 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 (http://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 the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
Most IETF participants are familiar with the saying "rough consensus and running code" [Tao] and can identify with its pragmatic approach. However, implementation is not a requirement for publication as an RFC. There are many examples of Internet-Drafts containing protocol specifications that have gone through to publication as Proposed Standard RFCs without implementation. Some of them may never get implemented.
Over time, a variety of policies have been applied within the IETF to consider running code. In the Routing Area, it used to be a requirement that one or more implementations must exist before an Internet-Draft could be published as a Proposed Standard RFC [RFC1264]. That RFC was later obsoleted and the requirement for implementation was lifted, but each working group was given the authority to impose its own implementation requirements [RFC4794] and at least one working group, Inter-Domain Routing (IDR), continues to require two independent implementations.
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The hypothesis behind the current document is that there are benefits to the IETF standardization process of producing implementations of protocol specifications before publication as RFCs. These benefits, which include determining that the specification is comprehensible and that there is sufficient interest to implement, are further discussed in Section 4.
This document describes a simple mechanism that allows authors of Internet-Drafts to record and publicize the status of known implementations by including an Implementation Status section. The document defines (quite informally) the contents of this section to ensure that the relevant information is included. This will allow reviewers and working groups to assign due consideration to documents that have the benefit of running code, which may serve as evidence of valuable experimentation and feedback that have made the implemented protocols more mature.
It is up to the individual working groups to use this information as they see fit, but one result might be the preferential treatment of documents, resulting in them being processed more rapidly. We recommend that the Implementation Status section should be removed from Internet-Drafts before they are published as RFCs. As a result, we do not envisage changes to this section after approval of the document for publication, e.g., the RFC errata process does not apply.
This process is not mandatory. Authors of Internet-Drafts are encouraged to consider using the process for their documents, and working groups are invited to think about applying the process to all of their protocol specifications.
The scope of this process is all Internet-Drafts (I-Ds) that contain implementable specifications, whether produced within IETF working groups or outside working groups but intended for IETF consensus. I-Ds published on the Independent Stream are explicitly out of scope. It is expected that the greatest benefit will be seen with Standards Track documents developed within working groups.
This process was initially proposed as an experiment in [RFC6982]. That document is now obsoleted, and the process advanced to Best Current Practice.
Historically, there have been other ways for experience based on protocol implementations to feed back into the IETF process. Many "implementation reports" have been published, in some cases several years after the protocol was originally published. Providing
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feedback to published protocols is a related goal, but different from the current document's focus. Two notable examples of published implementation reports are [RFC1369] and [RFC5080].
Each Internet-Draft may contain a section entitled "Implementation Status". This section, if it appears, should be located just before the "Security Considerations" section and contain, for each existing implementation, some or all of the following:
- The organization responsible for the implementation, if any.
- The implementation's name and/or a link to a web page where the implementation or a description of it can be found.
- A brief general description.
- The implementation's level of maturity: research, prototype, alpha, beta, production, widely used, etc.
- Coverage: which parts of the protocol specification are implemented.
- Version compatibility: what version/versions of the Internet-Draft are known to be implemented.
- Licensing: the terms under which the implementation can be used. For example: proprietary, royalty licensing, freely distributable with acknowledgement (BSD style), freely distributable with requirement to redistribute source (General Public License (GPL) style), and other (specify).
- Implementation experience: any useful information the implementers want to share with the community.
- Contact information: ideally a person's name and email address, but possibly just a URL or mailing list.
- The date when information about this particular implementation was last updated.
In addition, this section can contain information about the interoperability of any or all of the implementations, including references to test-case descriptions and interoperability reports, when such exist.
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Working group chairs and area directors (ADs) are requested to ensure that this section is not used as a marketing venue for specific implementations.
Since this information is necessarily time dependent, it is inappropriate for inclusion in a published RFC. The authors should include a note to the RFC Editor requesting that the section be removed before publication.
The following boilerplate text is proposed to head the Implementation Status section:
This section records the status of known implementations of the protocol defined by this specification at the time of posting of this Internet-Draft, and is based on a proposal described in RFC 7942. The description of implementations in this section is intended to assist the IETF in its decision processes in progressing drafts to RFCs. Please note that the listing of any individual implementation here does not imply endorsement by the IETF. Furthermore, no effort has been spent to verify the information presented here that was supplied by IETF contributors. This is not intended as, and must not be construed to be, a catalog of available implementations or their features. Readers are advised to note that other implementations may exist.
According to RFC 7942, "this will allow reviewers and working groups to assign due consideration to documents that have the benefit of running code, which may serve as evidence of valuable experimentation and feedback that have made the implemented protocols more mature. It is up to the individual working groups to use this information as they see fit".
Authors are requested to add a note to the RFC Editor at the top of this section, advising the Editor to remove the entire section before publication, as well as the reference to RFC 7942.
Sometimes it can be advantageous to publish the implementation status separately from the base Internet-Draft, e.g., on the IETF wiki:
- When the Implementation Status section becomes too large to be conveniently managed within the document.
- When a working group decides to have implementors, rather than authors, keep the status of their implementations current.
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- When a working group already maintains an active wiki and prefers to use it for this purpose.
- If the working group decides that the information is still valuable (and needs to be kept current) after the I-D is published as an RFC, and the Implementation Status section had been removed from it.
It is highly desirable for all readers of the Internet-Draft to be made aware of this information. Initially, this can be done by replacing the Implementation Status section's contents with a URL pointing to the wiki. Later, the IETF Tools may support this functionality, e.g., by including such a link in the HTML file of the document, similar to the IPR link.
If the implementation status is published separately from the I-D, then this information needs to be openly available without requiring authentication, registration, or access controls if it is to have any useful effects.
Publishing the information about implementations provides the working group with several benefits:
- Working group members, chairs, and ADs may use the information provided to help prioritize the progress of I-Ds, e.g., when there are several competing proposals to solve a particular problem.
- Similarly, the information is useful when deciding whether the document should be progressed on a different track (individual submission, Experimental, etc.).
- Making this information public and an explicit part of WG deliberations will motivate participants to implement protocol proposals, which in turn helps in discovering protocol flaws at an early stage.
- Other participants can use the software to evaluate the usefulness of protocol features, its correctness (to some degree), and other properties, such as resilience and scalability.
- WG members may choose to perform interoperability testing with known implementations, especially when they are publicly available.
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- In the case of open source, people may want to study the code to better understand the protocol and its limitations, determine if the implementation matches the protocol specification, and whether the protocol specification has omissions or ambiguities.
- And lastly, some protocol features may be hard to understand, and for such features, the mere assurance that they can be implemented is beneficial. We note though that code should never be used in lieu of a clear specification.
We do not specify here whether and to what degree working groups are expected to prefer proposals that have "running code" associated with them, over others that do not.
Working group chairs are invited to suggest this mechanism to document editors in their working groups, and to draw the attention of their working group participants to Implementation Status sections where they exist.
We would like to thank Stephen Farrell, who reawakened community interest in this topic. Several reviewers provided important input, including Loa Andersson, Dave Crocker, Ned Freed, Joel M. Halpern, Christer Holmberg, Denis Ovsienko, and Curtis Villamizar.
This document was originally prepared using the lyx2rfc tool, and we would like to thank Nico Williams, its author.