Network Working Group
Request for Comments: 4053
BCP: 103
Category: Best Current Practice
S. Trowbridge
Lucent Technologies
S. Bradner
Harvard University
F. Baker
Cisco Systems
April 2005

Procedures for Handling Liaison Statements to and from the IETF

Status of This Memo

This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. Distribution of this memo is unlimited.

Copyright Notice

Copyright © The Internet Society (2005).


This document describes the procedure for proper handling of incoming liaison statements from other standards development organizations (SDOs), consortia, and industry fora, and for generating liaison statements to be transmitted from IETF to other SDOs, consortia and industry fora. This procedure allows IETF to effectively collaborate with other organizations in the international standards community.

The IETF expects that liaison statements might come from a variety of organizations, and it may choose to respond to many of those. The IETF is only obligated to respond if there is an agreed liaison relationship, however.

Table of Contents

   1. Introduction ....................................................3
   2. Liaison Statements and Their Handling ...........................3
      2.1. Definitions ................................................3
      2.2. Liaison Statements .........................................4
           2.2.1. Contents of a Liaison Statement .....................4
         Envelope Information .......................4
         Liaison Content ............................5
      2.3. Addressee Responsibilities .................................6
      2.4. Lifetime of a Liaison Statement ............................7
   3. Tools for Handling Liaison Statements ...........................7
      3.1. Liaison Statements from Other SDOs, Consortia, and
           Fora to IETF ...............................................7
           3.1.1. Liaison Statement Submission ........................8
           3.1.2. Mechanism for Displaying Liaison Statements .........9
      3.2. Communicating IETF Information to Other SDOs,
           Consortia, and Fora ........................................9
           3.2.1. Spontaneously Generating Liaison Statements
                  to Other ............................................9
         Transmitting IETF Documents to
                           Other Organizations .......................10
         Requests for Information ..................10
         Requesting Comments on Work in Progress ...11
         Requests for Other Actions
                           (Besides Comments on IETF Drafts) .........11
           3.2.2. Responding to Incoming Liaison Statements ..........11
         Responding to Requests for Information ....11
         Responding to Requests for Comments .......12
         Responding to Request for Action ..........12
         Generating Liaison Statements .............13
   4. Security Considerations ........................................13
   5. Acknowledgements ...............................................14
   A. Implementation Road map ........................................15
      A.1. Phase I: Initial Implementation ...........................15
           A.1.1.   Displays .........................................15
           A.1.2.   Actions on Submission ............................16
   B. Phase II: Additional Instrumentation and Responses to
      Usage Experience ...............................................17
   Normative References ..............................................17

1. Introduction

This document describes the procedure for generating and handling liaison statements between the IETF and other SDOs, so that IETF can effectively collaborate with other organizations in the international standards community. These liaison statements are primarily exchanged between IETF and organizations with whom the IAB has created a liaison relationship (see [RFC4052]), although other organizations are not precluded. The procedures described in this document encompass all liaisons statements received from SDOs, whether or not a formal liaison arrangement is in place between the SDO and the IETF. The IETF is not obligated to respond to the liaison statement where there is no formal liaison arrangement.

The implementation of the procedure and supporting tools is occurring in a minimum of three phases. The initial phase has been the development of a prototype (in the best tradition of "rough consensus and running code"), by Sunny Lee of Foretec, in parallel with the development of this specification. The second phase is the conversion of that prototype to an operational tool. This operational tool lacks an automated tracking tool; rather, the liaison manager implements it in his or her own way. The third phase will include that tracking tool.

The specific supporting tools and their functionality described in this document are one possible way of providing automated support for the processes described in this document. Because specific tools and their functionality will change over time, the descriptions in this document are to be considered examples only and are not a normative part of this specification.

2. Liaison Statements and Their Handling

Let us first define what a liaison statement is (and is not), and set reasonable expectations. The expectations in this section are normative for a liaison statement sent by any SDO to the IETF.

2.1. Definitions

For purposes of clarity, we use the following definitions:

Addressee: The Working Group(s) (WG) or other party(s) in the IETF to

whom a liaison statement is addressed.

Assignee: The person responsible to act on a liaison statement,

initially either the person to whom it was addressed or the chair of the group to which it was addressed. The task may be reassigned to another person in the same or a different group as appropriate.

Liaison manager: A person designated to act as a manager of the

relationship between the IETF and a peer organization to ensure that communication is maintained, is productive, and is timely, as defined by sections 2.2 and 3 in [RFC4052].

Liaison statement: A letter as described in this document, exchanged

between organizations.

2.2. Liaison Statements

   A Liaison Statement is a business letter sent by one standards
   organization to another.  These organizations may be at any level
   (WG, Area, etc.)   Generally, the sender and receiver are peer
   organizations.  A liaison statement may have any purpose, but
   generally the purpose is to solicit information, make a comment or
   request an action.

2.2.1. Contents of a Liaison Statement

Liaison statements may be very formal or informal, depending on the rules of the body generating them. Any liaison statement, however, will always contain certain information, much as an business letter does. This information will include the following: Envelope Information

The following fields detail properties of the liaison statement. From:

The statement will indicate from what body it originates; for example, it may be from, an IETF WG or Area, an ITU-T Study Group, Working Party, or Question, etc. In this document, this body is the "sender". To:

The statement will indicate to which body it is. In this document, this body is the "addressee". Title:

The statement will contain a short (usually single line) statement of its context and content. Response Contact:

The sender will indicate the electronic mail address to which any response should be sent. Technical Contact:

The sender will indicate one or more electronic mail addresses (persons or lists) that may be contacted for clarification of the liaison statement. Purpose:

A liaison statement generally has one of three purposes and will clearly state its purpose using one of the following labels:

For Information: The liaison statement is to inform the addressee of

something, and expects no response.

For Comment: The liaison statement requests commentary from the

addressee, usually within a stated time frame.

For Action: The liaison statement requests that the addressee do

something on the sender's behalf, usually within a stated time frame.

In Response: The liaison statement includes a response to a liaison

statement from the peer organization on one or more of its documents and expects no further response. Deadline:

Liaison statements that request comment or action will indicate when the comment or action is required. If the addressee cannot accomplish the request within the stated period, courtesy calls for a response offering a more doable deadline or an alternative course of action. Liaison Content

The following fields are the substance of the liaison statement. IETF participants use a wide variety of systems, thus document formats that are not universally readable are problematic. As a result, documents enclosed with the body or attachments should be in PDF, W3C HTML (without proprietary extensions), or ASCII text format. If they were originally in a proprietary format such as Microsoft Word, the file may be sent, but should be accompanied by a generally readable file. Body:

As with any business letter, the liaison statement contains appropriate content explaining the issues or questions at hand. Attachments:

Attachments, if enclosed, may be in the form of documents sent with the liaison statement or may be URLs to similar documents including Internet Drafts.

2.3. Addressee Responsibilities

The responsibilities of the addressee of a liaison statement are the same as the responsibilities of any business letter. A liaison statement calls for appropriate consideration of its contents, and if a reply is requested and an appropriate relationship exists, a courteous authoritative reply within the expected time frame. The reply may be that the information was useful or not useful, that the requested action has been accomplished, it will be accomplished by a specified date, it will not be done for a specific reason, an answer to a question posed, or any other appropriate reply.

A liaison statement, like any other temporary document, must be considered for its relevance, importance, and urgency.

One hopes that a liaison statement will be sent to the right organization, but this cannot be assured. An SDO might send a liaison statement to a specific IETF Area whose Area Director (AD) deems it better handled by one of the WGs, or it might be sent to one WG when it should have gone to another. If a liaison statement arrives that appears misdirected, the assignee should promptly ask the liaison manager to redirect it appropriately. In some cases, a liaison statement may require consideration by multiple groups within the IETF; in such cases, one assignee takes the lead and responsibility for developing a response.

Liaison Statements are always important to the body that sent them. Having arrived at the appropriate body, the liaison statement may be more or less important to the addressee depending on its contents and the expertise of the sender. If the liaison statement seeks to influence the direction of a WG's development, it should receive the same consideration that any temporary document receives. The WG chair may request the sender's contacts to make their case to the IETF WG in the same manner that an author of an internet draft makes his or her case.

The urgency of a liaison statement is usually reflected in its deadline. A liaison statement for informational purposes may have no deadline; in such a case, a courteous "thank you" liaison statement is necessary to inform the sender that the liaison statement was received. The WG may then inform itself of the contents and close the document. A liaison statement specifying a deadline, however, gives the addressee a finite opportunity to influence the activity of another body; if it fails to react in a timely fashion, it may miss the opportunity.

2.4. Lifetime of a Liaison Statement

A liaison statement is a temporary document, much like an internet draft. If it affects IETF output, the normal expectation is that the resulting RFC will contain relevant information that remains pertinent. Retaining liaison statements that have been completely dealt with mostly serves to hide new ones and create the appearance of not dealing with them.

However, unlike an internet draft, liaison statements are often the only record the IETF has of the communication with the peer SDO. As such, some liaison statements are referred to for relatively long periods of time.

As a result, the IETF will archive liaison statements that have been fully dealt with, along with any attachments that may have been relevant, but do so in a manner obviously distinct from current liaison statements.

3. Tools for Handling Liaison Statements

Some tools have been developed for the IETF. Development is expected to continue. This section describes the basic tool and its intended use.

3.1. Liaison Statements from Other SDOs, Consortia, and Fora to IETF

The process of handling a liaison statement is more weighty than handling a business letter because it is important to a relationship with another SDO established by the IAB. To manage liaison statements, the IETF will offer three electronically accessible facilities: a form for submission of liaison statements, a mechanism organizing their contents and making them accessible, and a tracking system. Initially, the tracking system will be a manual procedure used by the liaison manager; in the future, this should be automated.

3.1.1. Liaison Statement Submission

The IETF Secretariat will provide an electronic method for submission of liaison statements.

The liaison statement submission mechanism is a form that requests the information listed in Section 2.2.1 from the user.

Submission of that information results in the following actions:

  • creation of a display mechanism containing the envelope data in Section and URLs pointing to the items from Section, an indication whether the liaison statement has been replied to, and if so, on what date,
  • the addition of a URL to the "outstanding liaison statements" summary mechanism,
  • when an automated tracking system has been implemented, a tickler/ status entry in the tracking system, assigned to the relevant chair or AD,
  • an email to the assignee copying
  • the liaison statement's technical contacts
  • The supervisor of the assignee (if it is to a WG, the relevant ADs; if to an AD, the IETF Chair),
  • The liaison manager for the sending SDO,
  • an alias associated with the assignee (WG/BOF or other open mailing list, Area Directorate, IESG, IAB, etc.)

This email should contain the URL to the liaison statement mechanism, text indicating that the liaison statement has arrived, requests appropriate consideration, and if a deadline is specified, a reply by the deadline.

The assignee has the capability of interacting with the liaison manager and the tracking system (once implemented), including replying, changing dates, reassignment, closing the liaison statement process, etc.

The liaison manager or tracking system's "tickle" function periodically reminds the assignee by email that the liaison statement has not yet been closed. This tickle email copies all of the above except the associated mailing alias.

3.1.2. Mechanism for Displaying Liaison Statements

The IETF site contains a section for current liaison statement activity. This consists of:

  • A submission mechanism,
  • A status/management mechanism for each active or recently closed liaison statement, and zero or more associated files.

The status/management mechanism contains a simple frame, showing the title of the liaison statement, the URL for its mechanism, and the organizations it is from and to.

The display for liaison statement itself contains:

  • the liaison statement envelope information (Section 2.2.1),
  • direct content (Section 2.2.1),
  • URLs for the various associated files
  • current status of the liaison statement: to whom it is assigned, its due date, and its status,
  • pointer to the liaison manager and tracking system entry for the liaison statement.
   o  reply-generation mechanism (see Section

3.2. Communicating IETF Information to Other SDOs, Consortia, and Fora

This includes liaison statements sent in reply to liaison statements sent by other bodies, and liaison statements being originated by the IETF.

3.2.1. Spontaneously Generating Liaison Statements to Other


Liaison Statements can be generated at a WG, Area, or IETF level to another organization. The respective (co)chair(s) are responsible for judging the degree of consensus for sending the particular liaison statement and deciding the content. The amount of consensus required to send a liaison statement varies greatly depending on its content. This section gives some rough guidance about how much consensus should be sought before sending a liaison statement to another organization. Transmitting IETF Documents to Other Organizations

The simplest case of approving sending of a liaison statement from IETF is when the information being transmitted consists of an IETF document that has some level of agreement within the IETF. The process that the document has already gone through to achieve its current status assures the necessary level of consensus. Any Standards Track RFC (Draft Standard, Proposed Standard, Internet Standard, BCP), and any WG document expected to be placed on the standards track, may be transmitted without concern.

Informational documents may also be exchanged readily when they represent a WG position or consensus, such as a requirements or architecture document.

In all cases, the document status must be appropriately noted. In the case of a WG Internet Draft, it must be clear that the existence of the draft only indicates that the WG has accepted the work item and, as the standard disclaimer says, the actual content can be treated as nothing more than Work in Progress.

Individually submitted Internet Drafts, Experimental or Historical RFCs, and non-WG informational documents should not be transmitted without developing further consensus within the relevant group, as these documents cannot be truthfully represented as any kind of IETF position. Requests for Information

Another type of liaison statement that can be generated without the need for extensive consensus building on the email list is a request for information. The (co)chairs(s) can generate such a liaison statement when they recognize, from the activities of the group, that some additional information is helpful, for example, to resolve an impasse (i.e., don't waste time arguing over what the real meaning or intent of another SDOs document is, just ask the other SDO and base further work on the "official" answer).

Other requests for information may request access to certain documents of other organizations that are not publicly available. Requesting Comments on Work in Progress

There may be cases when one feels that a document under development in the IETF may benefit from the input of experts in another relevant SDO, consortium, or forum. Generally, this is done before the text is "fully cooked" so that input from experts in another organization can be included in the final result. Comments would generally be solicited for a standards track WG Internet Draft and some level of consensus should be reached on the WG or other open mailing list that it is appropriate to ask another organization for comments on an IETF draft. Requests for Other Actions (Besides Comments on IETF Drafts)

There are many other kinds of actions that might reasonably be requested of another organization:

  • In the case of overlapping or related work in another organization, a request could be made that the other organization change something to align with the IETF work.
  • A request could be made for another organization to start a new work item (on behalf of IETF).
  • A request could be made for another organization to stop a work item (presumably because it overlaps or conflicts with other work in the IETF).

These kinds of requests are quite serious. They can certainly be made when appropriate, but should only be made when there is the clearest possible consensus within the particular WG, Area, or within the IETF at large.

3.2.2. Responding to Incoming Liaison Statements

Any incoming liaison statement that indicates that it is for "Comment" or for "Action" requires a response by the deadline; other liaison statements may also be replied to, although a reply is generally optional. It is the responsibility of the (co)chair(s) of the addressed organization to ensure that a response is generated by the deadline. Responding to Requests for Information

If another organization requests information that can be found in an IETF document of the types indicated in Section, this can be transmitted by the (co)chair(s) of the addressed group, indicating the level of agreement for the relevant document. Responding to Requests for Comments

If an incoming liaison statement requests comments on a document from another organization, a discussion will occur on the mailing list where participants can provide their comments.

If a clear consensus is evident from the pattern of comments made to the mailing list, the (co)chair(s) can summarize the conclusions in a reply liaison statement back to the originating organization.

If no clear consensus is evident from the pattern of comments on the mailing list, or if there is no further discussion, a response is still due to the originator. A summary of the email comments, or lack of interest in the issue, should be created and sent to the originator, and represented as "collected comments" rather than a consensus of the IETF group to which the liaison statement was addressed. It is possible to send this kind of a reply even if some of the comments are contradictory. Responding to Request for Action

A request for Action is a fairly serious thing. Examples of the kinds of actions that may be expected are:

  • In the case of overlapping or related work in another organization, another organization may request that the IETF align its work with that of the other organization.
  • A request could be made for IETF to undertake a new work item.
  • A request could be made for IETF to stop a work item (presumably because it overlaps or conflicts with other work in the originating organization).

Consensus of the receiving group within IETF is clearly necessary to fulfill the request. Fulfilling the request may require a great deal of time and multiple steps, for example, if initiating or stopping a work item requires a charter change.

There is, of course, no requirement that IETF perform the action that was requested. But the request should always be taken seriously, and a response is required. The originating organization must always be informed of what, if anything, the IETF has decided to do in response to the request. If the IETF decides not to honor the request, or to honor it with modifications, the response should include the reasons and, if applicable, the alternate course of action.

For tasks that require a great deal of time, it may be necessary that several liaison statements be sent back to the originating organization to report the status of the work and the anticipated completion time. The first of these liaison statements must be generated by the deadline indicated in the incoming liaison statement. Generating Liaison Statements

IETF participants, usually WG chairs, ADs, or other officials, need to be able to send liaison statements to other SDOs. The mechanism described in Section 3.1.2, listing appropriate contacts in other SDOs with which the IAB has established liaison relationships, provides that capability.

As a convenience, the liaison statement page described in Section 3.1.2 may be used to generate a reply. If a person (usually a WG chair or an AD) selects "reply", a new liaison statement page is generated from the existing one, reversing the addressing information. IETF documents should be referenced by URL, such as>file< or>file<.

The process of generating and approving transmission of liaison statements is a matter of IETF process and is specified in [RFC4052].

4. Security Considerations

One of the key considerations in developing this process has been the possibility of a denial of service attack on the IETF and its processes. Historically, the IETF has not always handled liaison statements effectively, resulting in people working in other organizations becoming frustrated with it. Various organizations have also used the liaison statement process to impose deadlines on IETF activities, which has been frustrating for all concerned - the IETF because it does not accept such deadlines, and other organizations because they feel ignored.

For this reason the submission process is automated. While the IETF cannot rate-limit the submitters, it can manage its internal pipelines.

This issue is exacerbated by the lack of any authentication on the part of the submitter. However, the IAB considers it important to be able to accept liaison statements whether or not a liaison relationship exists, so authentication of submitters is not an effective control.

5. Acknowledgements

This text has been prompted by discussions with numerous individuals within IETF and other SDOs and fora, including Gary Fishman and Bert Wijnen. It has been developed in cooperation with [RFC4052], which is to say with the express cooperation of the chair of the IAB, Leslie Daigle. Personal experiences and some "miscues" in coordinating work across ITU-T Study Group 15 and the IETF Sub-IP Area have also motivated this work. Some drafts addressing individual problems (for example, RFC 3427) make it clear that a more general, consistent solution is needed for dealing with outside organizations. Certain ideas have been borrowed from these texts.

Barbara Fuller, Sunny Lee, and Michael Lee developed a prototype and commented in detail on the document. Their inputs directly resulted in the appendices describing the implementation road map.

Appendix A. Implementation Road Map

This section documents the development program as of the time of the writing of this document. It is not normative.

A.1. Phase I: Initial Implementation

A.1.1. Displays

The descriptions of the required displays in Section 3.1.1 and Section 3.1.2 call for two sets of displays: one for the public (for viewing liaison statements), and one for submitters (for managing liaison statements).

Displays for public view of liaison statements include:

  • A Liaison Statements Web page that lists all incoming and outgoing liaison statements (specific fields TBD). The title of each liaison statement is a link to the details page for that liaison statement.
  • A detail page for each liaison statement that contains:
  • All of the information specified in the subsections of Section 2.2.1.
  • Links to all attachments that accompanied the liaison statement or to documents that are mentioned in the statement but were not provided as part of the submission.
  • Links to all related liaison statements (e.g., replies).

Displays for submitting and managing liaison statements include:

  • A summary page that offers mechanisms for:
  • Creating and submitting a new liaison statement.
  • Editing a liaison statement that the user has previously created and submitted.
  • Acting on a liaison statement that has been assigned to the user.
  • A template for creating and submitting a liaison statement. This template allows the user to enter the information specified in Section 2.2.1. The user is able to access the template at any time (from a list of liaison statements that the user has previously created and submitted), and update and resubmit the information.
  • A detail page for managing a liaison statement assigned to the user. This page is similar to the details page available to the public. However, it also includes:
  • A mechanism for replying to the liaison statement (initial implementation)
  • A link to a liaison statement tracking mechanism (future implementation)

A.1.2. Actions on Submission

Submission of a liaison statement results in the following actions:

  • The information is uploaded to the database.
  • An e-mail message with the content specified in Section 3.1.1 is sent to the addressee with copies to the addresses specified in Section 4.1, and to the Secretariat (as specified in [RFC4052]).
  • The liaison statement is added to the list on the Liaison Statements Web page.
  • Two detail pages are created for the liaison statement: one for the public (to view the liaison statement), and one for the sender and the assignee (to manage the liaison statement).

As specified in Section, when a user selects reply on the details page of a liaison statement, a template for creating and submitting a new liaison statement is generated from the existing one that copies "From" to "To" and specifies the respondent as the individual the response is coming "From". Submission of this reply liaison statement results in the same set of actions as submission of any new liaison statement. In addition, a link to the details page of this liaison statement is added to the list of related liaison statements on the details pages (both public and management) of the original liaison statement (i.e., the one to which the user replied).

Appendix B. Phase II: Additional Instrumentation and Responses to Usage


This section is for information, and is not normative.

The intended features of the future liaison statement tracking system are discussed in Section 3.1. They include mechanisms for:

  • Designating an assignee; the assignee is initially a person associated with the body (IAB, IESG, Area, WG, etc.) to which the liaison statement is addressed, but may subsequently be changed by an IETF participant.
  • Indicating the status of the liaison statement (e.g., actions required, actions taken, etc. Specific options TBD).
  • Sending ticklers to the assignee when action is required (with copies to whomever is appropriate).
  • Changing the status of the liaison statement, the deadline, or other attributes.
  • Reassigning responsibility.
  • Closing the liaison statement.

Normative References

   [RFC4052]  Daigle, L., "IAB Processes for Management of Liaison
              Relationships", RFC 4052, April 2005.

Authors' Addresses

Stephen J. Trowbridge
Lucent Technologies
1200 West 120th Avenue, Suite 232, Room 34Z07 Westminster, Colorado 80234-2795

   Phone: +1 303 920 6545
   Fax:   +1 303 920 6553
   Scott Bradner
   Harvard University
   29 Oxford St.
   Cambridge, Massachusetts  02138
   Phone: +1 617 495 3864
   Fax:   +1 617 492 8835
   Fred Baker
   Cisco Systems
   1121 Via Del Rey
   Santa Barbara, California  93117
   Phone: +1-408-526-4257
   Fax:   +1-413-473-2403

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