Clique - link-local chat rooms

Clique - link-local chat rooms A protocol for serverless link-local multi-user chat over reliable multicast. Copyright (c) 2007 Collabora Limited. This document may be distributed under the same terms as the Telepathy specification. proto-clique ProtoXEP Extension Standards Telepathy project XMPP Core XEP-0174 NOT YET ASSIGNED Simon McVittie simon.mcvittie@collabora.co.uk simon.mcvittie@collabora.co.uk 0.0.1 2007-11-02 smcv

First draft.

Clique is an extension of XEP-0174 to support multi-user chat. It consists of the following components:

a binary multicast message-passing protocol sometimes referred to as rMulticast, with retransmission/reliability, fragmentation/reassembly, causal ordering, and reliable membership semantics, in which messages are associated with a stream ID in the range 0 to 65535
XMPP-like XML messages sent with stream ID 0
optional auxiliary data (e.g. Tubes) sent with stream IDs 1-65535, with semantics signalled by XML messages in stream 0

The chat room behaves a lot like XMPP, and namespaces used in XMPP have their usual semantics. However, instead of a stream of XML as in XMPP, Clique's XMPP-like messages are individually well-formed XML documents.

XEP-0174 instance names are used for identification in a chat room.

The Clique XML namespace can also be used for certain elements sent over XEP-0174 unicast TCP streams, for instance to send invitations.

STRONGLY RECOMMENDED.

OPTIONAL.

FIXME: there need to be some examples of the actual Clique protocol here

In this example a chatroom called "Witchcraft" uses the multicast group 239.255.71.66, port 13251 (arbitrarily chosen).

We recommend that chatrooms use a random high port number in a random multicast group in the range 239.255.71.x.

In this example crone@desktop invites hecate@broom to the chatroom given above.

This would work just as well if the chatroom was not advertised in mDNS; this can be used to make "private" chatrooms. Note however that anyone with a network traffic sniffer can see the chatroom itself.


      
      
        
          Witchcraft
          239.255.71.66
          13251
          
          We need to plot Macbeth's doom, but the XMPP server is
            down
        
        
        You got a Clique chatroom invitation
      
      ]]>

OPTIONAL.

REQUIRED.

None.

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