Internet DRAFT - draft-ralston-mimi-messaging-requirements
draft-ralston-mimi-messaging-requirements
More Instant Messaging Interoperability T. Ralston
Internet-Draft The Matrix.org Foundation C.I.C.
Intended status: Informational 13 March 2023
Expires: 14 September 2023
Requirements of Interoperable Messaging
draft-ralston-mimi-messaging-requirements-00
Abstract
This document describes a set of requirements for messaging services
to interoperate.
These requirements are independent of any particular protocol or
messaging service, describing the set of features an interoperable
messaging service should support. Services should expect to go
beyond the requirements listed here, as MIMI's future content format
evolves.
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://turt2live.github.io/ietf-mimi-messaging-requirements/draft-
ralston-mimi-messaging-requirements.html. Status information for
this document may be found at https://datatracker.ietf.org/doc/draft-
ralston-mimi-messaging-requirements/.
Discussion of this document takes place on the More Instant Messaging
Interoperability Working Group mailing list (mailto:mimi@ietf.org),
which is archived at https://mailarchive.ietf.org/arch/browse/mimi/.
Subscribe at https://www.ietf.org/mailman/listinfo/mimi/.
Source for this draft and an issue tracker can be found at
https://github.com/turt2live/ietf-mimi-messaging-requirements.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Minimum Feature Set . . . . . . . . . . . . . . . . . . . . . 3
3. Maximum Feature Set . . . . . . . . . . . . . . . . . . . . . 3
3.1. Moderation and Personal Safety Functionality . . . . . . 5
4. Security Considerations . . . . . . . . . . . . . . . . . . . 5
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 5
1. Introduction
MIMI's charter seeks to establish an extensible set of messaging
features which make use of a future content format published by MIMI.
The charter also states that MIMI will use End-to-End Encryption
(E2EE), and that the content format must support E2EE.
This document describes a possible set of features that messaging
services should support. By extension, it also includes what MIMI
should support in its future content format. This document also
explores extensibility by contrasting a minimum and maximum feature
set for interoperability over MIMI.
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2. Minimum Feature Set
The following are the minimum features for an interoperable messaging
service. We consider group communication on the basis that 1:1
communication can typically be modelled as a subset of group
communication.
* Encryption, as required by MIMI's charter, and all associated
features (device tracking, etc).
* Reliable synchronisation of messages between messaging services,
avoiding gaps.
* Text and rich text to represent nearly all features persisted to
the conversation history.
* Ability to redact, remove, or delete a message, both as an
individual and as a room moderator.
* Invite, kick, ban, and leave membership states within a
conversation.
* Display names and avatars for users, to allow for personalization
beyond their identifier or username.
* Direct messaging, or conversations of exactly 2 users. The
underlying protocol might choose to treat DMs no different from
multi-user conversations, though messaging services might apply
semantics to represent DMs usefully to users.
* Differentiation between users and their abilities. For example,
roles for Moderators, Admins, etc.
3. Maximum Feature Set
This list is not exhaustive, but outlines some examples for what the
content format should be capable of supporting. The features that
messaging services currently support are:
* Names, topics/descriptions, and avatars for conversations for
personalization. Messaging services which don't support these
aesthetic features would ignore them.
* Read receipts/indicators when others in the room have read the
message. If a messaging service doesn't support them, that
service would not produce receipts and ignore received receipts.
This is a safe failure mode for the feature.
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* Typing notifications when others in the room are writing a
message. Like read receipts, services have the same safe failure
mode.
* Presence or online state. Like read receipts or typing
notifications, presence has the same safe fallback mode.
* Ability to reliably synchronize visible conversation history
between messaging services.
* Ability to port conversation history between messaging services.
* Images, videos, files, and audio in messages. The content format
would specify a fallback to (rich) text to support messaging
services that are primarily text-based, such as by specifying a
URL for users to click on to view the relevant media.
* Voice messages are semantically distinct from file transfers, but
can be represented as audio file uploads with minor decoration
metadata in the content format.
* Replies (also called "rich quoting") to reference specific
messages or parts of messages. A content format specification
might define a fallback format to ensure messaging services that
do not support replies can still render something which looks
vaguely like a reply.
* Threads to organize a conversation. A content format
specification might define a fallback to Replies to keep a
reader's context in tact when using a messaging service that
doesn't support threads.
* 1:1 VoIP. Messaging services which don't support VoIP could be
asked to say "a call is happening, but you can't join on this
device" under a content format, or, if the conference protocol
allows, a link for the user to click and join the call externally.
* Multi-party VoIP.
* Message editing. A content format could define a fallback which
references the edited message with a reply and using a difference
syntax to highlight applicable changes.
* Reactions. A content format might decide to provide a fallback by
using replies to associate an emoji or textual reaction to a given
message, or simply ignore it.
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As implied above, a future content format document would be
responsible for describing the exact details of how features fall
back, if at all. This document offers non-binding suggestions.
3.1. Moderation and Personal Safety Functionality
Currently out of scope for MIMI, moderation, anti-spam, etc
functionality would likely be considered part of the "Maximum Feature
Set". A suitable protocol could support functionality such as
ignoring or blocking individual users, "who can send invites to me"
controls, and similar features without needing to have a specific
content format specification necessarily. For example, preventing
invites from being received could simply be a rejected action over
the delivery and transport layer.
4. Security Considerations
Security considerations for these features would be handled by other
documents, such as a content format document.
5. IANA Considerations
This document has no IANA actions.
Author's Address
Travis Ralston
The Matrix.org Foundation C.I.C.
Email: travisr@matrix.org
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