| Internet-Draft | moq-chat | October 2024 |
| Frindell | Expires 24 April 2025 | [Page] |
MoQ Chat (moq-chat) is a simple text based protocol for exercising MoQ Transport.¶
This note is to be removed before publishing as an RFC.¶
The latest revision of this draft can be found at https://afrind.github.io/draft-frindell-moq-chat/draft-frindell-moq-chat.html. Status information for this document may be found at https://datatracker.ietf.org/doc/draft-frindell-moq-chat/.¶
Discussion of this document takes place on the Media Over QUIC Working Group mailing list (mailto:[email protected]), which is archived at https://mailarchive.ietf.org/arch/browse/moq/. Subscribe at https://www.ietf.org/mailman/listinfo/moq/.¶
Source for this draft and an issue tracker can be found at https://github.com/afrind/draft-frindell-moq-chat.¶
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 24 April 2025.¶
Copyright (c) 2024 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 (https://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 Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License.¶
MoQ Chat (moq-chat) is a simple text based protocol for exercising MoQ Transport [MOQT]. The protocol allows many participants to join a virtual chat room, publish messages to the room and receive messages published by others.¶
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.¶
Commonly used terms in this document are described below.¶
The protocol requires a MoQ relay to act as a chat server. The relay maintains the set of connected clients that have announced a chat track.¶
Every chat has a unique ID. The ID is a string of arbitrary length and uniquely identifies the chat. The creation of chat IDs and discovery of the relay is out of the scope of this document.¶
Each chat participant has a chat track. The namespace of the track is ("moq-chat", <id>, <user-id>, <device-id>, <timestamp>) and the name track is "chat".¶
To join the chat a participant sends a SUBSCRIBE_NAMESPACE message to the relay with a namespace prefix ("moq-chat", <id>). MoQ Relays track the current state of all announced namespaces and namespace subscriptions, and forward any matching ANNOUNCE or UNANNOUNCE messages to interested endpoints.¶
The participant also sends an ANNOUNCE message for their chat track namespace.¶
When receiving an ANNOUNCE that matches the chat prefix, the client extracts the client's user-id, device-id and timestamp from the third, fourth and fifth tuple elements, respectively. The client SHOULD subscribe to the latest timestamp track for each (user-id, device-id) pair.¶
Upon receiving an UNANNOUNCE, a client SHOULD UNSUBSCRIBE from that matching track if it had previously subscribed.¶
Each chat message is sent in a new Group and new Object. The format of a chat chat message this draft is UTF-8 Encoded text. There is no limit to the length of a chat message beyond those imposed on QUIC streams. Chat clients MUST send an END_OF_GROUP message for each Group.¶
The starting Group ID for each track starts at 0 and increments by 1. The Object ID for each chat message starts at 0 and increments by 1.¶
When a user leaves the chat, they SHOULD send an UNANNOUNCE message for their namespace. They also SHOULD publish an object with status END_OF_TRACK_AND_GROUP on their chat track, since they will start a new track if they rejoin. Finally, they SHOULD send an UNSUBSCRIBE message for any tracks they subscribed to before closing their Transport Session.¶
If all publishers of a given namespace disconnect from the relay abruptly, the relay will send UNANNOUNCE messages matching SUBSCRIBE_NAMESPACE to interested endpoints.¶
The RECOMMENDED forwarding preference for the chat track is Subgroup, with all subgroup IDs set to 0, though clients MAY use other forwarding preferences at their discretion.¶
If a client detects a MOQT session has been closed by the relay, it assumes the relay has exited or crashed, and does not attempt to reconnect.¶
TODO Security¶
This document has no IANA actions.¶
TODO acknowledge.¶